- Optically induced linking of protein and nanoparticles to gold surfaces
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Attachment of molecules and proteins to surfaces is of great interest for the development of a large variety of applications. We present herein a novel approach to efficiently couple a molecule of choice to biological building blocks. We synthesized and employed a new derivative of 5-bromo-7-nitroindoline to attach nucleophilic molecules and proteins to gold surfaces by photochemical activation. The reaction can be seen as a photoactivated alternative to the activated ester type chemistries that are commonly used to attach proteins or molecules to surfaces. We characterize the reaction by UV-vis and NMR spectroscopy, and as test of principle experiment, we show that we can attach proteins to surfaces and demonstrate that we can functionalize gold nanoparticles by this optically induced cross-linking reaction.
- Moth-Poulsen, Kasper,Kofod-Hansen, Vesna,Kamounah, Fadhil S.,Hatzakis, Nikos S.,Stamou, Dimitrios,Schaumburg, Kjeld,Christensen, J?rn B.
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- Selective detection of non-aromatic pesticides via cyclodextrin-promoted fluorescence modulation
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Reported herein is the detection of aliphatic pesticides using cyclodextrin-promoted fluorescence modulation. The introduction of the pesticide leads to noticeable changes in the emission of a fluorophore held in close proximity by cyclodextrin, leading to a pesticide detection system that operates with 100% successful differentiation and low limits of detection.
- Discenza, Dana J.,Levine, Mindy
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- Fabrication of Gradient and Patterned Organic Thin Films by Bipolar Electrolytic Micelle Disruption Using Redox-Active Surfactants
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Bipolar electrochemistry could be regarded as a powerful approach for selective surface modification due to the beneficial feature that a wirelessly controllable potential distribution on bipolar electrodes (BPEs). Herein we report a bipolar electrolytic micelle disruption (BEMD) system for the preparation of shaped organic films. A U-shaped bipolar electrolytic system with a sigmoidal potential gradient on the BPE gave gradient-thin films including various interesting organic compounds, such as a polymerizable monomer, an organic pigment and aggregation induced emission (AIE) molecules. The gradient feature was characterized by UV–Vis absorption, thickness measurements and surface morphology analysis. Corresponding patterned films were also fabricated using a cylindrical bipolar electrolytic setup that enables site-selective application of the potential on the BPE. Such a facile BEMD approach will open a long-term perspective with respect to organic film preparation.
- Zhou, Yaqian,Shida, Naoki,Tomita, Ikuyoshi,Inagi, Shinsuke
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- Formation of organic thin films by electrolysis of surfactants with the ferrocenyl moiety
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The formation of organic thin films by controlled-potential electrolysis (oxidation) of an aqueous solution containing surfactants with a ferrocenyl moiety and an organic compound incorporated in micelles or in a dispersed organic pigment with use of the surfactants is examined. Opaque films of five azo dyes, vinylcarbazole, cetyl alcohol, dioctadecyldimethylammonium chloride, and 4,4′-didodecylviologen are formed through the former mechanism. Transparent films of phthalocyanine compounds (MPc (M = H2, Cu)), four halogen derivatives of CuPc, three perylene derivatives, and two quinones are formed through the latter mechanism. The scanning electron micrograph studies show that crystal size of the film increases with electrolysis time in the case of the former mechanism and is the same for the added particles in the case of the latter mechanism. The adsorption isotherm of the surfactant on the pigment particle surface shows that they form monolayers at saturation and their desorption starts at slightly above the critical micelle concentration (cmc). These results suggest that the films formed through the former and the latter mechanisms are prepared by disruption of micelles and desorption of surfactant from the pigment surface, respectively.
- Saji, Tetsuo,Hoshino, Katsuyoshi,Ishii, Yoshiyuki,Goto, Masayuki
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- Electrochromism of a bipolar reversible redox-active ferrocene-viologen linked ionic liquid
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A ferrocene-viologen linked “bipolar” type redox-active ionic liquid ([FcC11VC1][TFSI]2) was synthesized as an electrochromic (EC) material that functions without any other additives: solvents, supporting electrolytes and sacrificial agents. The efficiency of a prototype symmetrical EC cell was 70 cm2 C?1 at 1.0 V. The EC process was stable even after over 10?000 potential cycles.
- Tahara, Hironobu,Baba, Rei,Iwanaga, Kodai,Sagara, Takamasa,Murakami, Hiroto
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- Synthesis of [1]benzothieno[3,2-b][1]benzothiophene pendant and norbornene random co-polymers via ring opening metathesis
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2-Octyl-7-(11-(cis-5-norbornene-endo-2,3-dicarboxylicimide)undecane)[1] benzothienopheno[3,2-b] benzothienophene (1) was synthesised and co-polymerised with varying amounts of 1-decyl(cis-5-norbornene-endo-2,3-dicarboxylic) imide (2) or norbornene, using a ruthenium catalyst, to produce a series of random co-polymers.
- Combe, Craig M. S.,Biniek, Laure,Schroeder, Bob C.,McCulloch, Iain
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- Supramolecular assemblies formed by new L-lysine derivatives of viologens?
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L-Lysine derivatives of viologens form supramolecular assemblies of fibers and ribbons in some aromatic solvents, and the charge separation reaction in these self-assembling systems proceeds with a similar efficiency to the MV2+ system.
- Suzuki,Waraksa,Nakayama,Hanabusa,Kimura,Shirai
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- Self-assembly of pyridinium-functionalized anthracenes: Molecular-skeleton-directed formation of microsheets and microtubes
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Two amphiphilic regioisomers, 9-AP (1-[11-(9-anthracenylmethoxy)-11- oxoundecyl]pyridinium bromide), and 2-AP (1-[11-(2-anthracenyl methoxy)-11-oxoundecyl]pyridinium bromide), were synthesized and their assembly behaviors were studied. Due to the anisotropic features of the anthracene structure, different substituted positions on the anthracene ring lead 9-AP and 2-AP to adapt "shaver" and "spatula"-like molecular shapes, respectively, which consequently dictate the structure of their final assemblies. While "shaver"-shaped 9-AP assembled into microsheets, driven by π-π interactions, "spatula"-shaped 2-AP assembled into microtubular structures, promoted primarily by charge-transfer interactions. Self-assembly: Two anthracene-based amphiphilic regioisomers, 9-AP and 2-AP, were synthesized. Due to the anisotropy of the anthracene structure, different substitutions on anthracene rings led 9-AP and 2-AP to adapt different molecular structures and self-assembled morphologies (see figure). While "shaver"-shaped 9-AP assembled into microsheets through π-π interactions, "spatula"-shaped 2-AP transformed into microtubes due to charge-transfer interactions.
- Hu, Jun,Wang, Peiyi,Lin, Yuan,Zhang, Jidong,Smith, Mark,Pellechia, Perry J.,Yang, Song,Song, Baoan,Wang, Qian
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- DNA-binding and photocleavage properties of cationic porphyrin-anthraquinone hybrids with different lengths of links
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Four cationic porphyrin-anthraquinone (Por-AQ) hybrids differing in lengths of flexible alkyl linkage, 5-[4-(1-N-anthraquinonon-yl)-l-oxophenyl]-10,15,20-tris(N-methylpyridinium-4-yl)porphyrin triiodide, (l = acetyl, pentanoyl, octanoyl, undecanoyl, designed as [AQATMPyP]I3, [AQPTMPyP]I3, [AQOTMPyP]I3 and [AQUTMPyP]I3, respectively, see Fig. 1), were synthesized and their interactions with DNA were investigated. The results of spectroscopic, denaturation and viscosity measurements suggest that [AQATMPyP]I3 binds to DNA through non-intercalative mode while the other three hybrids with longer links bind via bis-intercalative mode. Ethidium bromide (EB) competition experiment was carried out to determine the binding constants (Kb) of these compounds for CT DNA, and [AQPTMPyP]I3 shows the largest Kb among these hybrids. The photocleavage mechanism and wavelength-dependent cleaving abilities of these hybrids to pBR322 plasmid DNA were also comparably investigated.
- Zhao, Ping,Xu, Lian-Cai,Huang, Jin-Wang,Fu, Bo,Yu, Han-Cheng,Zhang, Wei-Hong,Chen, Jian,Yao, Jun-Hua,Ji, Liang-Nian
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- Development of pyrene-based fluorescent ether lipid as inhibitor of SK3 ion channels
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We report the synthesis of three bioactive pyrene-based fluorescent analogues of Ohmline which is the most efficient and selective inhibitor of SK3 ion channel. The interaction of these Ohmline-pyrene (OP1-3) with liposomes of different composition reveals that only OP2 and OP3 are readily integrated into liposomes. Fluorescence measurements indicate that, depending on their concentration, OP2 and OP3 exist either as monomer or as a mixture of monomer and excimers within the liposome bilayer. Among the three Ohmline Pyrene compounds (OP1-3) only OP2 is able to reduce SK3 currents and is the first efficient fluorescent modulator of SK3 channel as revealed by patch clamp measurements (- 71.3 ± 13.3% at 10 μM) and by its inhibition of SK3-dependent cancer cell migration at (?32.5% ± 4.8% at 1 μM). We also report the first fluorescence study on living breast cancer cells (MDA-MB-231) showing that OP2 is rapidly integrated in bio-membranes followed by cell internalization.
- Bauduin, Alicia,Papin, Marion,Chant?me, Aurélie,Couthon, Hélène,Deschamps, Laure,Requejo-Isidro, Jose,Vandier, Christophe,Jaffrès, Paul-Alain
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- Supercapacitors based on polyelectrolyte/ferrocenyl-surfactant complexes with high rate capability
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In this paper, a composite of the Polyelectrolyte/Ferrocenyl-Surfactant Complexes (PFSC) coated on carbon paper (CP) was applied as an electrode material for supercapacitors. The as-prepared composite possessed a specific capacitance as high as 214 F g-1 calculated from discharge curve with a current density of 0.8 A g-1 and this observation was deemed to be because of its ferrocenyl moieties. Furthermore, the specific capacitances calculated from cyclic voltammograms were 145 and 103 F g-1 at the potential scan rates of 20 and 50 mV s-1, which kept at 77.6% and 55.4% of the corresponding value at 10 mV s-1 (187 F g-1). This suggested that the composite possessed a good rate capability as a novel redox active electrode material for pseudo-capacitors. In short, for the first time the composite PFSC/CP was reported as a promising electrode material for efficient supercapacitors.
- Tan, Guiping,Cheng, Zhiyu,Qiu, Yongfu,Huang, Weiqing,Fan, Hongbo,Ren, Biye
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- Synthesis and liquid crystallinity of dendronized carbohydrate liquid crystal
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A dendronized carbohydrate thermotropic liquid crystal was synthesized by attaching wedge-shaped mesogens onto a carbohydrate core. These molecules self-organize into chiral columnar hexagonal mesophase with each column slice (4.5 thicknesses) filled with average of two molecules. The supramolecular model was further optimized by molecular dynamics simulation. Moreover, chirality successfully expressed in columnar hexagonal mesophase by dendronized carbohydrate molecules may provide inspiration in searching for chiral mesophase of carbohydrate liquid crystals.
- Yang, Liulin,Dong, Yanming,Hu, Xiaolan,Liu, Anhua
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- Array-based detection of persistent organic pollutants via cyclodextrin promoted energy transfer
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We report herein the selective array-based detection of 30 persistent organic pollutants via cyclodextrin-promoted energy transfer. The use of three fluorophores enabled the development of an array that classified 30 analytes with 100% accuracy and identified unknown analytes with 96% accuracy, as well as identifying 92% of analytes in urine.
- Serio, Nicole,Moyano, Daniel F.,Rotello, Vincent M.,Levine, Mindy
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- Stabilizing bolaform amphiphile interfacial assemblies by introducing mesogenic groups
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We describe the synthesis and characterization of the mesogen-bearing bolaform amphiphile 4,4′-dihydroxybiphenylbis(11-pyridinium-N-yl-undecanoic ester) dibromide (BP-10) and its solid/liquid interfacial self-assembly. Cylindrical micelles are directly observed by atomic force microscopy (AFM) at the interface between mica and the aqueous solution above the critical micelle concentration (cmc). In situ and ex situ AFM studies indicate that the cylindrical micelles are stable both at the mica/solution interface and in the dry state. The enhanced stability of the micellar structures enables a detailed investigation of their self-assembly behavior and supramolecular structures at the interface. The adsorption model proposed here is supported by the variation of the interfacial self-assemblies on changing the solution concentration and substrate temperature.
- Wang, Mingfeng,Qiu, Dengli,Zou, Bo,Wu, Tao,Zhang, Xi
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- Comprehensive investigation of self-assembled monolayer formation on ferromagnetic thin film surfaces
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We report a simple, universal method for forming high surface coverage SAMs on ferromagnetic thin (≤100 nm) films of Ni, Co, and Fe. Unlike previous reports, our technique is broadly applicable to different types of SAMs and surface types. Our data constitutes the first comprehensive examination of SAM formation on three different ferromagnetic surface types using two different surface-binding chemistries (thiol and isocyanide) under three different preparation conditions: (1) SAM formation on electroreduced films using a newly developed electroreduction approach, (2) SAM formation on freshly evaporated surfaces in the glovebox, and (3) SAM formation on films exposed to atmospheric conditions beforehand. The extent of SAM formation for all three conditions was probed by cyclic voltammetry for surfaces functionalized with either (11-thiolundecyl)ferrocene (Fc-(CH2)11-SH) or (11-isocyanoundecyl)ferrocene (Fc-(CH2)11-NC). SAM formation was also probed for straight-chain molecules, hexadecanethiol and hexadecaneisocyanide, with contact angle measurements, X-ray photoelectron spectroscopy, and reflection-absorption infrared spectroscopy (RAIRS). The results show that high surface coverage SAMs with low surface-oxide content can be achieved for thin, evaporated Ni and Co films using our electroreduction process with thiols. The extent of SAM formation on electroreduced films is comparable to what has been observed for SAMs/Au and to what we observe for SAMs/Ni, Co, and Fe samples prepared in the glovebox.
- Hoertz, Paul G.,Niskala, Jeremy R.,Dai, Peng,Black, Hayden T.,You, Wei
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- Intramolecular photoreactions of phthalimide-alkene systems. Macrocyclic synthesis through the remote Paterno-Buchi reaction of phthalimide with indole derivatives
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Upon irradiation, phthalimide-indole in bichromophoric systems underwent intramolecularly remote Paterno-Buchi reaction to give oxeto[2,3-b]indole derivatives containing macrocycles, in competition with Norrish type II reaction.
- Takechi,Machida,Nishizono,Kanaoka
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- Synthesis of [14,14,14-2H3] 12-hydroxytetradecanoic acid and [13,14-2H2] 11-hydroxytetradecanoic acid useful as tracers to study a (11E)-desaturation reaction in Spodoptera littoralis
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The synthesis of deuterium labeled 11- and 12-hydroxytetradecanoic acids to study a (11E) desaturase in the moth Spodoptera littoralis is reported. [14,14,14-2H3] 12-hydroxytetradecanoic acid was synthesized in four steps from 11-iodo-1-undecene in 49% overall yield. Deuterium was introduced by reaction of an epoxy ester with (CD3)2CuLi. The preparation of [13,14-2H2] 11-hydroxytetradecanoic acid was carried out in six steps from 11-bromoundecanoic acid in 55% overall yield. In this case, label was introduced by deuteration of an homoallyl alcohol with D2, using the Wilkinson catalyst. Incubation of pheromone glands with either of both acids did not lead to the formation of the labeled (11E)-tetradecanoic acid.
- Navarro,Fabrias,Camps
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- Facile, convenient synthesis of highly pure ω-ferrocenylalkanethiols as probes for self-assembled monolayer (sam) on gold surface
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High purity synthesis of ω-ferrocenylalkanethiols (Fc(CH2)n-SH, n=6, 8, 11) was developed for their use in self-assembled monolayers on gold surface. The method employs a separation and purification of isothiuronium salt 6 to improve the purity of final products 7. The use of hazardous mercury in the Clemmensen reduction of acylferrocene 4 to alkylferrocenes 5 is avoided by an alternative LAH/AlCl3 reduction.
- Tazaki, Masato,Okada, Kenji,Yakata, Kenshi,Nakano, Koji,Sakai, Masashi,Yonemitsu, Tadashi
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- Molecular Conformation in Charge Tunneling across Large-Area Junctions
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Self-assembled monolayers are predicated on thermodynamic equilibrium; hence, their properties project accessible relaxation pathways. Herein, we demonstrate that charge tunneling correlates with conformational degrees of freedom(s). Results from open chain and cyclic head groups show that, as expected, distribution in tunneling data correlates with the orientation of the head group, akin to the odd-even effect and more importantly the degree of conformational freedom, but fluctuates with applied bias. Trends in nature of distributions in current density illuminate the need for higher statistical moments in understanding these rather dynamic systems. We employ skewness, kurtosis, and estimation plots to show that the conformational degree of freedom in the head group significantly amplifies the odd-even effect and may lead to enhanced or perturbed tunneling based on whether the head group is on an odd- or even-parity spacer.
- Chen, Jiahao,Du, Chuanshen,Norris, Sean R.,Thakur, Abhishek,Thuo, Martin,Vanveller, Brett
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- Controlled self-assembly manipulated by charge-transfer interactions: From tubes to vesicles
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Transfer request: A self-assembled-supramolecular charge-transfer complex of 1-(11-oxo-11-pyren-1-ylmethoxy)undecyl)-pyridinium bromide (PYR) and ethane-1,2-diyl bis(3,5-dinitrobenzoate) (DNB) is shown to form vesicular aggregates in aqueous solution, in contrast to the tubular aggregates of pure PYR (see picture). A curvature-dependent mechanism for this change is proposed. (Figure Presented)
- Wang, Chao,Yin, Shouchun,Chen, Senlin,Xu, Huaping,Wang, Zhiqiang,Zhang, Xi
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- Synthesis and properties of polythiophene containing mesogenic group at 3-position of thiophene ring
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Various kinds of polythiophene derivatives were synthesized and thermal properties were examined by DSC, polarized microscopic and X-ray diffraction observations. Fusibility and solubility of these polymers deeply depends upon the polymerization methods and polarity of the mesogenic group. Polymerization was carried out by oxidation and poly-condensation methods. The polarity at the end of mesogenic group plays an important role for solubility and fusibility of the polymer in the case of oxidative polymerization. 3-Substituted polythiophene having polar group such as cyano or nitro at the end of mesogenic group was soluble in polar solvent and fusibility at higher temperature. The polymer having polar group at the end of mesogenic group prepared by mild polymerization condition such as polycondensation exhibited a clear smectic texture and also showed electrochemically active by cyclic voltammograms.
- Koide,Iida
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- Efficacious redox-responsive gene delivery in serum by ferrocenylated monomeric and dimeric cationic cholesterols
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Herein, we present the design and synthesis of new redox-active monomeric and dimeric (gemini) cationic lipids based on ferrocenylated cholesterol derivatives for gene delivery. The cationic cholesterols are shown to be transfection efficient after being formulated with the neutral helper lipid DOPE in the presence of serum (FBS). The redox activity of the resulting co-liposomes and their lipoplexes could be regulated using the alkanyl ferrocene moiety attached to the ammonium head groups of the cationic cholesterols. Atomic force microscopy (AFM), dynamic light scattering (DLS) and zeta potential measurements were performed to characterize the co-liposomal aggregates and their complexes with pDNA. The transfection efficiency of lipoplexes could be tuned by changing the oxidation state of the ferrocene moiety. The gene transfection capability was assayed in terms of green fluorescence protein (GFP) expression using pEGFP-C3 plasmid DNA in three cell lines of different origins, namely Caco-2, HEK293T and HeLa, in the presence of serum. The vesicles possessing ferrocene in the reduced state induced an efficient transfection, even better than a commercial reagent Lipofectamine 2000 (Lipo 2000) as evidenced by flow cytometry and fluorescence microscopy. All the co-liposomes containing the oxidized ferrocene displayed diminished levels of gene expression. Gene transfection events from the oxidized co-liposomes were further potentiated by introducing ascorbic acid (AA) as a reducing agent during lipoplex incubation with cells, leading to the resumption of transfection activity. Assessment of transfection capability of both reduced and oxidized co-liposomes was also undertaken following cellular internalization of labelled pDNA using confocal microscopy and flow cytometry. Overall, we demonstrate here controlled gene transfection activities using redox-driven, transfection efficient cationic monomeric and dimeric cholesterol lipids. Such systems could be used in gene delivery applications where transfection needs to be performed spatially or temporally. This journal is
- Vulugundam, Gururaja,Kumar, Krishan,Kondaiah, Paturu,Bhattacharya, Santanu
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- The photoinduced electron transference of porphyrin-anthraquinone dyads bridged with different lengths of links
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The photoinduced electron transference (PET) interaction in porphyrin containing donor-acceptor (D-A) molecules is of great importance in nature and a significant part of the PET research has been devoted to the study of its mechanism ("through-space" or "through-bond") in these decades. Herein we synthesized a series of covalently linked porphyrin-anthraquinone dyads (Por-Cn-AQ) bridged with flexible alkoxy chains at different lengths (n = 1, 4, 10) and investigated their intramolecular PET using a combination of electronic absorption, steady-state fluorescence and decayed luminescence spectra. The experimental results show that the PET efficiency depends on the length of the flexible linkage between the porphyrin and anthraquinone moieties. Meanwhile, theoretical calculation applying the density functional theory (DFT) was also carried out to give the frontier orbital distribution and the optimized structures of these dyads. It is found that the orientation of the dyad with high PET efficiency is disadvantageous to π-π interaction. Thus, the PET of these dyads seemingly is best compatible with a "through-bond" (superexchange) mechanism.
- Zhao, Ping,Huang, Jin-Wang,Xu, Lian-Cai,Ma, Li,Ji, Liang-Nian
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- Systems for orthogonal self-assembly of electroactive monolayers on Au and ITO: An approach to molecular electronics
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Simultaneous exposure of Au and In2O3/SnO2 (ITO) electrodes to an equimolar solution of a thiol and a carboxylic acid or a thiol and phosphonic acid results in the selective attachment of the thiol to the Au electrode and the carboxylic or phosphonic acid to the ITO electrode. This selective surface-attachment chemistry is termed "orthogonal self-assembly" (OSA) and can be used to direct the spontaneous assembly of molecular reagents onto Au and ITO rnicrostructures. The selectivity of the thiols for Au and the carboxylic or phosphonic acids for ITO is determined by a combination of cyclic voltammetry experiments using ferrocene-tagged molecules, scanning Auger microscopy, and imaging secondary ion mass spectrometry (SIMS) to map the distribution of thiols, carboxylic acids, and phosphonic acids on derivatized Au and ITO microstructures. Simultaneous exposure of Au and ITO electrodes for 30 min to an equimolar solution of 11-mercaptoundecanoylferrocene (I) and 12-ferrocenyldodecanoic acid (III) results in a coverage ratio I:III of approximately 100:1 on Au and 1:45 on ITO, as determined by cyclic voltammetry. A 30-min exposure of Au and ITO electrodes to an equimolar solution of I and 6-ferrocenylhexylphosphonic acid (V) yields a coverage ratio of I:V of 30:1 on Au and better than 1:100 on ITO. The coverages of I, III, and V on the Au and ITO electrodes can be determined using cyclic voltammetry by virtue of the difference in redox potential between the acylferrocene center in I and the alkylferrocene centers in III and V. Typical converages of I on Au (4 × 10-10 mol/cm2) and III and V on ITO (6 × 10-10 and 3 × 10-10 mol/cm2, respectively) after 30 min of derivatization correspond to approximately a monolayer of redox-active molecules in each case. Long derivatization times (12-15 h) result in small or insignificant changes in the coverage ratios of these reagents on both Au and ITO electrodes, demonstrating that the OSA is essentially complete within 30 min. Surface analysis by X-ray photoelectron spectroscopy, scanning Auger microscopy, and imaging SIMS of Au and ITO microstructures and Si3N4 surfaces exposed to equimolar solutions of I and perfluorodecanoic acid (IV), or 12,12,12-trifluorododecanethiol (II) and V, reveal the selective assembly of these reagents on the Au and ITO microstructures and their absence on the insulating Si3N4 substrate. The orthogonal self-assembly process described here provides a promising method by which individual molecules could be spontaneously oriented and connected between closely-spaced, externally-addressable electrodes.
- Gardner, Timothy J.,Frisbie, C. Daniel,Wrighton, Mark S.
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- Selective reductive desorption of a SAM-coated gold electrode revealed using fluorescence microscopy
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The reductive desorption of a self-assembled monolayer (SAM) of a fluorescent thiol molecule (BodipyC10SH) from Au was characterized using electrochemistry and epi-fluorescence microscopy. Molecular luminescence is quenched near a metal surface, so fluorescence was only observed for molecules reductively desorbed and then separated from the electrode surface. Fluorescence imaging showed that reductive desorption was selective, with desorption occurring from different regions of the Au electrode depending on the extent of the negative potential excursion. When desorbed, the molecules were sufficiently mobile, diffusing away from the electrode surface, thereby preventing oxidative readsorption. At sufficiently negative desorption potentials, all of the thiol was desorbed from the electrode surface, resulting in fluorescence at the air/solution interface. The selective removal of the thiol monolayer from distinct regions was correlated to features on the electrode surface and was explained through potential-dependent interfacial energies. This in situ electrofluorescence microscopy technique may be useful in sensor development.
- Shepherd, Jeff L.,Kell, Arnold,Chung, Emily,Sinclar, Chad W.,Workentin, Mark S.,Bizzotto, Dan
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- Ammonium derivatives of chromenones and quinolinones as lead antimicrobial agents
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A series of novel ammonium derivatives were synthesized and examined for their antimicrobial efficacy. Comparison of antimicrobial spectrum revealed that compounds 9, 11, 16 and 23 had strong potential against pathogens in vitro. Cytotoxicity results showed compound 9 to be least toxic, it is non-toxic to A549 and U87 cells in MTT assay and exhibits marginal toxicity (15-20%) to human erythrocytes at a concentration of 1000 μg/ml as compared to 100% lysis of cells by 31.25 μg/ml of the standard drug amphotericin B. This compound has MIC values in the range of 1.95-31.25 μg/disc in DDA against different pathogens and may considered to be an important lead antimicrobial molecule for further exploration.
- Gupta, Shilpi,Singh, Seema,Kathuria, Abha,Kumar, Manish,Sharma, Sweta,Kumar, Ram,Parmar, Virinder S,Singh, Bharat,Gupta, Anjali,Eycken, Erik Van Der,Sharma, Gainda L,Sharma, Sunil K
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- Synthesis of quaternary, long-chain N-alkyl amides and their corrosion inhibition in acidic media
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New cationic surfactants were synthesized by the quaternization of a number of straight-chain amide derivatives with triethylamine or pyridine. The corrosion inhibition tests of the surface-active compounds were performed at room temperature for 24 h on carbon steel coupons in acidic media using the gravimetric method. The acidic media used were 1.5 M HCl and 1.5 M H 2SO4. Almost all of the synthesized cationic surfactants showed efficient inhibition of corrosion in the test. To establish the inhibition efficiencies of the inhibitors, surface characterization studies (contact angle measurements, SEM analysis and optical profilometer images) of the metal coupons used were performed.
- ?ztürk, Serkan,Y?ld?r?m, Ayhan,?etin, Mehmet,Tavasl?, Mustafa
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- Redox-controlled reversible micelles transition and lyotropic liquid-crystalline behavior of novel polymerizable ferrocenyl surfactants
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A novel photopolymerizable surfactant with ferrocenyl group, (11-ferrocenylundecyl) (ethyl methacrylate) dimethylammonium bromide (I+), was synthesized through the reaction of 11-bromoundecyl ferrocene and N,N-(dimethylamino) ethyl methacrylate. Based on the results of voltammetric cycle, the small potential difference ΔE was 72 mV, which indicates that the I+ has good redox reversibility. The critical micellar concentration (CMC) values were about 0.5 and 22.7 mM for I+ in the reduction (CMCred) and oxidation state (CMCox) and it could aggregate and disaggregate by using redox reaction and photopolymerization when its concentrations was between their CMCred and CMCox values. The lyotropic liquid-crystalline properties of I+ in water were investigated by X-ray diffraction (XRD) and plarized optical microscope (POM). The results indicate when the concentration of the I+ solution over 40 wt %, an ordered lamellar liquid crystal structure was formed. With increasing concentration, the nanoscopic long-range order improved. Moreover, the lyotropic liquid-crystalline properties of I+ could also be controlled by using redox reaction and photopolymerization. In a word, the novel polymerizable ferrocenyl surfactants are good environmental responsive materials and can potentially act as the drug carrier and the scavenger for removing dissolved organic impurities in water.
- Cheng, Zhiyu,Chang, Xueyi,Qiu, Yongfu,Tan, Guiping,Cheng, Faliang,Fan, Hongbo,Ren, Biye
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- Initial evaluation of 99mTc-tricarbonyl-cyclopentadienyl fatty acids derivatives as SPECT tracers for myocardium
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Fatty acids are myocardial metabolic agent for detecting myocardial ischemia and infraction. However, no 99mTc-labeled fatty acids had potential use in clinical practice. In this study, 99mTc-CpTT-10-oxo-para-PPA (1d), 99mTc-CpTT-11-oxo-para-PPA (2d), 99mTc-CpTT-12-oxo-para-PPA (3d), 99mTc-CpTT-11-oxo-ortho-PPA (4d), and 99mTc-CpTT-11-oxo-meta-PPA (5d) were synthesized by a double ligand transfer reaction, and their biological behaviors were investigated. Compound 2d achieved good heart to blood ratio (3.39 at 5?min after intravenous), and 2d showed high-heart uptake of 6.20%?ID/g at 5?minutes after injection. Compound 3d displayed a prolonged retention in the myocardium (1.43%?ID/g at 60?min after injection). Radioactivity accumulation in the lungs, spleen, and blood was eliminated rapidly. In vivo, metabolite analysis presented that compound 6d may be metabolite of 2d through β-oxidation in tissue. Unfortunately, the biodistribution studies of 1d, 2d, 3d, 4d, and 5d showed fast heart clearance and poor heart to liver ratios, which suggested that the 5 99mTc-labeled fatty acid analogues cannot be used for diagnosis.
- Liu, Jianping,Wang, Huan,Wang, Shuxia,Xue, Qianqian,Wang, Dawei,Wang, Hang,Zhang, Huabei
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- Separately enhanced dual emissions of the amphiphilic derivative of 2-(2′-hydroxylphenyl) benzothiazole by supramolecular complexation
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Here, we report separately enhanced dual emissions of the amphiphilic derivative of 2-(2′-hydroxyphenyl)benzothiazole (denoted as HBT-11) by supramolecular complexation with cyclodextrins (CDs). When dispersed in water, HBT-11 shows two relatively weak emission bands, which can be assigned to the emissions of enol- and keto-forms, the two tautomers, owing to excited-state intramolecular proton transfers. Upon the addition of α-CD and β-CD, the keto- and enol-emissions, respectively, are separately enhanced; the enhancement effect is due to the formation of HBT-11/α-CD and HBT-11/β-CD complexes through multiple hydrogen bonding and host-guest interactions, respectively. It is worth to note that the keto-emission caused by the complex of HBT-11/α-CD has a much shorter wavelength compared with that of the aggregates formed by pure HBT-11. To the best of our knowledge, this is the first time that a study on keto-emission of the isolated HBT chromophore has been reported.
- Wu, Chengfeng,Jin, Yingzhi,Li, Dahua,Ding, Lan,Xing, Yuzhi,Zhang, Kaicheng,Song, Bo
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Read Online
- Co-liposomes of redox-active alkyl-ferrocene modified low MW branched PEI and DOPE for efficacious gene delivery in serum
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Herein, we present six new lipopolymers based on low molecular weight, branched polyethylenimine (BPEI 800 Da) which are hydrophobically modified using ferrocene terminated alkyl tails of variable lengths. The effects of degree of grafting, spacer length and the redox state of ferrocene in the lipopolymers on the self assembly properties were investigated in detail by TEM, AFM, DLS and zeta potential measurements. The assemblies displayed an oxidation induced increase in the size of the aggregates. The co-liposomes comprising the lipopolymer and a helper lipid, 1,2-dioleoyl phosphatidyl ethanolamine (DOPE), showed excellent gene (pDNA) delivery capability in a serum containing environment in two cancer cell lines (HeLa and U251 cells). Optimized formulations showed remarkably higher transfection activity than BPEI (25 kDa) and were also significantly better than a commercial transfection reagent, Lipofectamine 2000 as evidenced from both the luciferase activity and GFP expression analysis. Oxidation of ferrocene in the lipopolymers led to drastically reduced levels of gene transfection which was substantiated by reduced cellular internalization of fluorescently labelled pDNA as detected using confocal microscopy and flow cytometry. Moreover, the transfection inactive oxidized lipopolyplexes could be turned transfection active by exposure to ascorbic acid (AA) in cell culture medium during transfection. Endocytosis inhibition experiments showed that gene expression mediated by reduced formulations involved both clathrin and caveolae mediated pathways while the oxidized formulations were routed via the caveolae. Cytotoxicity assays revealed no obvious toxicity for the lipopolyplexes in the range of optimized transfection levels in both the cell lines studied. Overall, we have exploited the redox activity of ferrocene in branched PEI-based efficient polymeric gene carriers whose differential transfection activities could be harnessed for spatial or temporal cellular transfections.
- Kumar, Krishan,Vulugundam, Gururaja,Kondaiah, Paturu,Bhattacharya, Santanu
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Read Online
- Synthesis of Long-Chain Alkanoyl Benzenes by an Aluminum(III) Chloride-Catalyzed Destannylative Acylation Reaction
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This paper describes the facile synthesis of haloaryl compounds with long-chain alkanoyl substituents by the destannylative acylation of haloaryls bearing tri-n-butyltin (Bu3Sn) substituents. The method allows the synthesis of many important synthons for novel functional materials in a highly efficient manner. The halo-tri-n-butyltin benzenes are obtained by the lithium-halogen exchange of commercially available bis-haloarenes and the subsequent reaction with Bu3SnCl. Under typical Friedel-Crafts conditions, i.e., the presence of an acid chloride and AlCl3, the haloaryls are acylated through destannylation. The reactions proceed fast (5 min) at low temperatures and thus are compatible with aromatic halogen substituents. Furthermore, the method is applicable topara-,meta-, andortho-substitution and larger systems, as demonstrated for biphenyls. The generated tin byproducts were efficiently removed by trapping with silica/KF filtration, and most long-chain haloaryls were obtained chromatography-free. Molecular structures of several products were determined by X-ray single-crystal diffraction, and the crystal packing was investigated by mapping Hirshfeld surfaces onto individual molecules. A feasible reaction mechanism for the destannylative acylation reaction is proposed and supported through density functional theory (DFT) calculations. DFT results in combination with NMR-scale control experiments unambiguously demonstrate the importance of the tin substituent as a leaving group, which enables the acylation.
- Roemer, Max,Keaveney, Sinead T.,Proschogo, Nicholas
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p. 9007 - 9022
(2021/07/20)
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- POLYCYCLIC AROMATIC HYDROCARBON-BASED COMPOUNDS FOR MOLECULAR ELECTRONIC DEVICE AND MOLECULAR ELECTRONIC DEVICES COMPRISING SAME
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The present invention relates to polycyclic aromatic hydrocarbon-based compounds, for a molecular electronic device, enabling molecular rectification, and molecular electronic devices comprising a molecular layer formed by means of the compounds self-assembled on an electrode. The compounds according to the present invention can realize rectifying properties by being introduced between electrodes and thus enable a high rectification ratio by means of low voltage driving, and thus can be substituted for a silicon-based diode device and, more particularly, can be utilized for a wearable device, Bluetooth, an IoT enabling device and the like which require low voltage driving.
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Paragraph 0053-0054
(2021/11/26)
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- Intramolecular Cyclization of Brominated Oxime Ether Promoted with Ytterbium(0) to the Synthesis of Cyclic Imines
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The first utility of ytterbium(0) as a mediating-metal in the intramolecular cyclization of brominated oxime ether was reported in this paper. In contrast to the prior methods, the N–O bond was used as a receptor of nucleophilic reagent, rather than as a source of N-centered radicals. Cyclic imines were obtained in this one-pot reaction with a broad scope of substrates and feasible reaction conditions.
- Wang, Yiqiong,Huang, Fei,Zhang, Songlin
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supporting information
p. 5178 - 5181
(2020/08/13)
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- Modulating electron transfer in ferrocene-naphthoquinone dyads: New insights in parameters influencing ET efficiency
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Electron transfer (ET) constitutes a key process for several biological transformations, including solar energy conversion in bacteria and plants. Nowadays, numerous synthetic systems have been proposed to mimic such kind of natural occurring process. In this work, we elucidate the factors that mostly influence the electron transfer process in ferrocene-naphthoquinone dyads. In particular, the connection between the two redox units has been varied, in order to study the ET dependence from: i) the distance between donor-acceptor units and ii) the oxidation potential of the donor species. No interaction among the two moieties has been detected at the ground state, while efficient electron transfer process was observed following excitation of the naphthoquinone through UV-light, as well as upon the aid of a Lewis acid promoter in solution. Moreover, DFT calculations have been performed to support the experimental data.
- Sabuzi, Federica,Coletti, Alessia,Pomarico, Giuseppe,Floris, Barbara,Galloni, Pierluca,Conte, Valeria
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- Iminyl Radicals by Reductive Cleavage of N-O Bond in Oxime Ether Promoted by SmI2: A Straightforward Synthesis of Five-Membered Cyclic Imines
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A new generation method of N-centered radicals from the reductive cleavage of the N-O bond in oxime ether promoted by SmI2 is reported for the first time. The in-situ-generated N-centered radicals underwent intramolecular cyclization to afford five-membered cyclic imines in two manners: N-centered radical addition and N-centered anion nucleophilic substitution. From a synthetic point of view, an efficient synthetic method of five-membered cyclic imines was developed. A mechanism of the transformation was proposed.
- Huang, Fei,Zhang, Songlin
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supporting information
p. 7430 - 7434
(2019/10/11)
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- METHOD
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The invention provides mitochondria-targeted chemiluminescent agents and their use in methods of photodynamic therapy (PDT). In particular, the invention provides compounds of general formula (I), and their pharmaceutically acceptable salts: (I) in which A represents a chemiluminescent moiety; each L, which may be the same or different, is either a direct bond or a linker; each B, which may be the same or different, represents a mitotropic moiety; n is an integer from 1 to 3, preferably 1; and x is an integer from 1 to 3, preferably 1. Such compounds find particular use in the treatment of deeply- sited tumours, e.g. glioblastoma multiforme (GBM), when used in combination with a photosensitizer or photosensitizer precursor.
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Page/Page column 35
(2020/01/11)
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- Identification of a fluorescent small-molecule enhancer for therapeutic autophagy in colorectal cancer by targeting mitochondrial protein translocase TIM44
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Objective As the modulation of autophagic processes can be therapeutically beneficial to cancer treatment, the identification of novel autophagic enhancers is highly anticipated. However, current autophagy-inducing anticancer agents exert undesired side effects owing to their non-specific biodistribution in off-target tissues. This study aims to develop a multifunctional agent to integrate cancer targeting, imaging and therapy and to investigate its mechanism. Design A series of mitochondria-targeting near-infrared (NIR) fluorophores were synthesised, screened and identified for their autophagy-enhancing activity. The optical properties and biological effects were tested both in vitro and in vivo. The underlying mechanism was investigated using inhibitors, small interfering RNA (siRNA), RNA sequencing, mass spectrometry and human samples. Results We have screened and identified a new NIR autophagy-enhancer, IR-58, which exhibits significant tumour-selective killing effects. IR-58 preferentially accumulates in the mitochondria of colorectal cancer (CRC) cells and xenografts, a process that is glycolysis-dependent and organic anion transporter polypeptide-dependent. IR-58 kills tumour cells and induces apoptosis via inducing excessive autophagy, which is mediated through the reactive oxygen species (ROS)-Akt-mammalian target of rapamycin (mTOR) pathway. RNA sequencing, mass spectrometry and siRNA interference studies demonstrate that translocase of inner mitochondrial membrane 44 (TIM44)-superoxide dismutase 2 (SOD2) pathway inhibition is responsible for the excessive ROS, autophagy and apoptosis induced by IR-58. TIM44 expression correlates positively with CRC development and poor prognosis in patients. Conclusions A novel NIR small-molecule autophagy-enhancer, IR-58, with mitochondria-targeted imaging and therapy capabilities was developed for CRC treatment. Additionally, TIM44 was identified for the first time as a potential oncogene, which plays an important role in autophagy through the TIM44-SOD2-ROS-mTOR pathway.
- Huang, Yinghui,Luo, Shenglin,Wang, Yang,He, Jintao,Luo, Peng,Chen, Zelin,Liu, Tao,Tan, Xu,Shi, Chunmeng,Zhou, Jie,Ou, Juanjuan,Miao, Hongming,Liang, Houjie
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p. 307 - 319
(2018/07/31)
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- Preparation method and application of technetium-99m-labeled triphenylphosphine derivative
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The invention relates to a preparation method and application of a technetium-99m-labeled triphenylphosphine derivative and can effectively solve problems of preparation of the triphenylphosphine derivative and use for a cationic myocardial imaging agent. The preparation method comprises the following steps: reacting omega-brominated aliphatic acid I to obtain omega-brominated aliphatic acyl chloride II, and enabling the omega-brominated aliphatic acyl chloride II to react with ferrocene to generate an intermediate III in which the chlorine is substituted by the ferrocene; enabling the intermediate III to react with triphenylphosphine and obtaining a solid product precursor IV through separation; adding a Na99mTcO4 leacheate with a radioactive activity of 740 MBq in a polytetrafluorine high-pressure tank, blow-drying with N2, adding the product precursor, Cr(CO)6, CrCL3 and methanol and sealing the polytetrafluorine high-pressure tank; performing magnetic stirring under an oil bath, then taking an ice bath, filtering, purifying a filtrate with HPLC, and analyzing and identifying to obtain the technetium-99m labeled triphenylphosphine derivative. The preparation method provided by the invention is simple, easy to operate, rich in raw materials and low in yield, is effectively used for preparing an SPECT myocardial perfusion imaging agent and is great in medical and commercial values.
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Paragraph 0033; 0034; 0035
(2018/09/21)
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- Effect of topology structure on the electrochemical behavior of hydrogen-bonded self-assembled Poly(4-vinylpyridine) -ferrocenyl dendron complexes
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In this report, two new redox-responsive complexes with different dendritic tail chain number (P4VP- nFc, n = 1, 2) were prepared via the hydrogen-bonded self-assembly of poly(4-vinylpyridine) and ferrocenyl-modified percec-type dendrons. These complexes exhibited a crystalline phase for P4VP-1Fc and liquid crystalline for P4VP-2Fc at room temperature. The cyclic voltammetry measurement shows that the electrode process of P4VP-nFc (n = 1, 2) films was diffusion controlled and the reversibility of the electrode process for the P4VP-2Fc films became better than that for the P4VP-1Fc. Moreover, the redox peak current |ip| increased with increasing dendritic tail chain number n in the complex, because the complex film formed with 2Fc-COOH has the looser stacking of alkyl chains, which was favorable for the electrolyte diffusion and charge transfer. The present results demonstrate that the electrochemical activity of the redox-responsive poly(4-vinylpyridine) -ferrocenyl dendron complex can be easily tuned using the dendritic tail chain with different numbers. These complexes may be used as new kinds of modified electrodes.
- Cheng, Zhiyu,Li, Chongqing,Qiu, Yongfu,Chang, Xueyi,Tan, Guiping,Ren, Biye
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p. 223 - 229
(2017/07/04)
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- Discovery of a Small-Molecule Inhibitor of Interleukin 15: Pharmacophore-Based Virtual Screening and Hit Optimization
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Interleukin (IL)-15 is a pleiotropic cytokine, which is structurally close to IL-2 and shares with it the IL-2 β and γ receptor (R) subunits. By promoting the activation and proliferation of NK, NK-T, and CD8+ T cells, IL-15 plays important roles in innate and adaptative immunity. Moreover, the association of high levels of IL-15 expression with inflammatory and autoimmune diseases has led to the development of various antagonistic approaches targeting IL-15. This study is an original approach aimed at discovering small-molecule inhibitors impeding IL-15/IL-15R interaction. A pharmacophore and docking-based virtual screening of compound libraries led to the selection of 240 high-scoring compounds, 36 of which were found to bind IL-15, to inhibit the binding of IL-15 to the IL-2Rβ chain or the proliferation of IL-15-dependent cells or both. One of them was selected as a hit and optimized by a structure-activity relationship approach, leading to the first small-molecule IL-15 inhibitor with sub-micromolar activity.
- Quéméner, Agnès,Maillasson, Mike,Arzel, Laurence,Sicard, Benoit,Vomiandry, Romy,Mortier, Erwan,Dubreuil, Didier,Jacques, Yannick,Lebreton, Jacques,Mathé-Allainmat, Monique
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supporting information
p. 6249 - 6272
(2017/08/02)
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- Ferrocenyl-based redox-reversible surfactant and preparation method of thereof
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The invention provides a ferrocenyl-based redox-reversible surfactant and a preparation method thereof, and relates to the field of redox switch type surfactants. The ferrocenyl-based redox-reversible surfactant is prepared from a precursor compound ferrocene, acetyl chloride, zinc amalgam, bromoundecanoic acid, thionyl chloride and trimethylamine as raw materials. The synthesized surfactant molecules are easy to prepare, the yield of the intermediate diacetylferrocene is effectively improved, a new feeding sequence is provided, and the problem of reduction of ferrocene due to oxidation reaction is effectively solved. The surfactant can be used as an electrode surface modification material for glucose detection.
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Paragraph 0020; 0023
(2018/01/19)
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- Controlled generation of singlet oxygen by porphyrin-appended gold nanoparticles
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Porphyrin-appended gold nanoparticles with different chain lengths were synthesized to examine the control over photosensitization. The efficiencies evaluated by singletoxygen generation were adjusted by the average number of porphyrins on one gold nanoparticle and the particle size regardless of the linker chain length between porphyrin site and gold core.
- Shinohara, Akira,Shinmori, Hideyuki
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supporting information
p. 1341 - 1343
(2017/08/02)
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- Rationally Designed Supramolecular Organic Hosts for Benzo[a]pyrene Binding and Detection
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A series of electronically dissymmetric all-organic macrocycles were synthesized using straightforward synthetic procedures. These macrocycles vary in the nature of the substituents, the geometry of the linkage that connects the electron-deficient aromatic ring, the type of linkage, and the presence or absence of a heteroaromatic ring. These small structural variations impart significant differences in the performance of these macrocycles in binding benzo[a]pyrene, with binding constants up to 2.5 × 104 M-1 obtained. They also lead to significant differences in their ability to promote non-covalent energy transfer from benzo[a]pyrene to a BODIPY fluorophore, with energy transfer efficiencies ranging from 32 % to 398 %. These differences can be explained using a variety of computational investigative techniques, which highlight the flexibility of the macrocycle architectures to accommodate benzo[a]pyrene and to promote close donor-acceptor interactions. A series of 10 organic macrocycles were designed, synthesized, and evaluated for their ability to bind benzo[a]pyrene and facilitate benzo[a]pyrene to BODIPY energy transfer. These results highlight the relationship between structural features of hosts, their overall conformations, and their ability to participate in intermolecular interactions and supramolecular applications.
- Radaram, Bhasker,Levine, Mindy
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supporting information
p. 6194 - 6204
(2015/10/06)
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- Synthesis, antiproliferative, and c-Src kinase inhibitory activities of 4-oxo-4H-1-benzopyran derivatives
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A new class of 4-oxo-4H-1-benzopyran derivatives were synthesized and their antiproliferative activity examined against a panel of three human cancer cell lines, that is, breast carcinoma (MDA-MB-468), ovarian adenocarcinoma (SK-OV-3), and colorectal adenocarcinoma (HT-29). Two compounds, that is, 3-hexyl-7,8-dihydroxy-4-oxo-4H-1-benzopyran and (E)-ethyl 3-(7-methoxy-4-oxo-4H-1-benzopyran-3-yl)acrylate were found to be potent against all three cancer cell lines studied at 50 μM concentration. Also, the inhibitory potency of the compounds was evaluated against active Src kinase. A few of these compounds exhibited modest Src kinase inhibitory activity (IC50 = 52-57 μM). Structure-activity relationship studies with respect to the nature and position of substituents on the lead compounds could be further exploited for the design and development of more potent antiproliferative agents and/or Src kinase inhibitors.
- Chand, Karam,Tiwari, Rakesh K.,Kumar, Sumit,Shirazi, Amir Nasrolahi,Sharma, Sweta,Van Der Eycken, Erik V.,Parmar, Virinder S.,Parang, Keykavous,Sharma, Sunil K.
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p. 562 - 572
(2015/03/30)
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- Synthesis and cytostatic evaluation of 4-N-alkanoyl and 4-N-alkyl gemcitabine analogues
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The coupling of gemcitabine with functionalized carboxylic acids (C9-C13) or reactions of 4-N-tosylgemcitabine with the corresponding alkyl amines afforded 4-N-alkanoyl and 4-N-alkyl gemcitabine derivatives. The analogues with a terminal hydroxyl group on the alkyl chain were efficiently fluorinated under conditions that are compatible with protocols for 18F labeling. The 4-N-alkanoylgemcitabines showed potent cytostatic activities in the low nanomolar range against a panel of tumor cell lines, whereas cytotoxicity of the 4-N-alkylgemcitabines were in the low micromolar range. The cytotoxicity for the 4-N-alkanoylgemcitabine analogues was reduced approximately by 2 orders of magnitude in the 2′-deoxycytidine kinase (dCK)-deficient CEM/dCK - cell line, whereas cytotoxicity of the 4-N-alkylgemcitabines was only 2-5 times lower. None of the compounds acted as efficient substrates for cytosolic dCK; therefore, the 4-N-alkanoyl analogues need to be converted first to gemcitabine to display a significant cytostatic potential, whereas 4-N-alkyl derivatives attain modest activity without measurable conversion to gemcitabine.
- Pulido, Jesse,Sobczak, Adam J.,Balzarini, Jan,Wnuk, Stanislaw F.
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supporting information
p. 191 - 203
(2014/02/14)
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- Charge-transfer interactions for the fabrication of multifunctional viral nanoparticles
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A facile strategy to fabricate multifunctional viral nanoparticles was described by introducing charge-transfer interactions between a pyrenyl motif with dinitrophenyl and pyridinium-contained guest molecules. This journal is
- Hu, Jun,Wang, Peiyi,Zhao, Xia,Lv, Lin,Yang, Song,Song, Baoan,Wang, Qian
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supporting information
p. 14125 - 14128
(2015/02/19)
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- Efficient detection of polycyclic aromatic hydrocarbons and polychlorinated biphenyls via three-component energy transfer
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Reported herein is the detection of highly toxic polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) via proximity-induced non-covalent energy transfer. This energy transfer occurs in the cavity of γ-cyclodextrin, and is efficient even with the most toxic PAHs and least fluorescent PCBs. The low limits of detection and potential for selective detection using array-based systems, combined with the straightforward experimental setup, make this new detection method particularly promising.
- Serio, Nicole,Miller, Kayla,Levine, Mindy
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supporting information
p. 4821 - 4823
(2013/06/27)
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- Highly efficient non-covalent energy transfer in all-organic macrocycles
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The use of aromatic organic macrocycles as supramolecular hosts for non-covalent energy transfer is reported herein. These macrocycles lead to stronger binding and more efficient energy transfer compared to commercially available γ-cyclodextrin. This energy transfer was particularly efficient for the highly toxic benzo[a]pyrene with a fluorescent BODIPY acceptor, with up to a 5-fold increase in the fluorophore emission observed.
- Radaram, Bhasker,Potvin, Joshua,Levine, Mindy
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supporting information
p. 8259 - 8261
(2013/09/12)
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- Synthesis and characterization of some novel higher C,N-diphenyl nitrones, isoxazolines, and mercaptobenzimidazoles as oleochemicals
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Some novel long-chain nitrones, isoxazolines, and (1H-benzo[d]-imidazol-2- ylthio) derivatives were synthesized. Nitrones, N-{4-[2-(tetradecylthio)acetoxy] benzylidene}aniline oxide, and N-[4-(12-oxo-2,5,8,11-tetraoxadocosan-22-yloxy) benzylidene]aniline oxide were prepared via the reaction of -phenylhydroxylamine with the corresponding aromatic aldehydes. The isoxazolines were prepared from undec-10-en-1-ol and benzonitrile-N-oxide which was generated in situ. The 1H-benzo[d]-imidazol-2-ylthio derivatives were synthesized via the replacement reaction of -bromo esters and 2-mercaptobenzimidazole.
- Yldrm,Cetin
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experimental part
p. 952 - 964
(2012/08/07)
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- Liquid crystalline 4-(2,3 Dihydroxypropoxy) diphenyl 4-n-alcoxy acids
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4-(2,3 Dihydroxypropoxy) diphenyl 4-oxy-hexanoic acid and 4-(2,3 dihydroxypropoxy) diphenyl 4-oxy-undecanoic acid have been synthesized and analyzed by IR and NMR experiments. The liquid crystalline character and the phase transitions of these two acids have been studied by differential scanning calorimetry (DSC) and variable temperature X-ray diffraction (VTXRD). These two liquid crystalline monomers are designed to be flexible, rigid and polyfunctional, so that they can be used in the synthesis of new macromolecules with side chain liquid crystals.
- Lopez-Velazquez, Delia,Hernandez-Sosa, Armando R.,Perez, Ernesto,Castillo-Rojas, Susana
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experimental part
p. 175 - 184
(2012/04/05)
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- Replacing -CH2CH2- with -CONH- does not significantly change rates of charge transport through AgTS-SAM//Ga 2O3/EGaIn junctions
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This paper describes physical-organic studies of charge transport by tunneling through self-assembled monolayers (SAMs), based on systematic variations of the structure of the molecules constituting the SAM. Replacing a -CH2CH2- group with a -CONH- group changes the dipole moment and polarizability of a portion of the molecule and has, in principle, the potential to change the rate of charge transport through the SAM. In practice, this substitution produces no significant change in the rate of charge transport across junctions of the structure AgTS-S(CH 2)mX(CH2)nH//Ga2O 3/EGaIn (TS = template stripped, X = -CH2CH2- or -CONH-, and EGaIn = eutectic alloy of gallium and indium). Incorporation of the amide group does, however, increase the yields of working (non-shorting) junctions (when compared to n-alkanethiolates of the same length). These results suggest that synthetic schemes that combine a thiol group on one end of a molecule with a group, R, to be tested, on the other (e.g., HS~CONH~R) using an amide-based coupling provide practical routes to molecules useful in studies of molecular electronics.
- Thuo, Martin M.,Reus, William F.,Simeone, Felice C.,Kim, Choongik,Schulz, Michael D.,Yoon, Hyo Jae,Whitesides, George M.
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supporting information; experimental part
p. 10876 - 10884
(2012/08/28)
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- A water-soluble pillar[6]arene: Synthesis, host-guest chemistry, and its application in dispersion of multiwalled carbon nanotubes in water
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The first water-soluble pillar[6]arene was synthesized. Its water solubility can be reversibly controlled by changing the pH. This solubility control was used in reversible transformations between nanotubes and vesicles and dispersion of multiwalled carbon nanotubes in water.
- Yu, Guocan,Xue, Min,Zhang, Zibin,Li, Jinying,Han, Chengyou,Huang, Feihe
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supporting information; scheme or table
p. 13248 - 13251
(2012/09/25)
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- In situ spectroeletrochemistry and cytotoxic activities of natural ubiquinone analogues
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Quinones are a group of potent antineoplastic agents. Here we described effective and facile routes to synthesize a series of ubiquinone analogues (UQAs). These unique compounds have been investigated by electrochemistry and in situ UV-vis spectroelectrochemistry to explore their electron-transfer processes and radical properties in aprotic media. The structure-activities relationships of inhibiting cancer cell proliferation of UQAs were examined in murine melanoma B16F10 cells using a 72 h continuous exposure MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Our results revealed that UQAs had improved antiproliferative activity and displayed better inhibitory effects than natural ubiquinone 10. The cytotoxic activities of UQAs were correlated to the semiubiquinone radicals, which were confirmed by in situ electron spin resonance (ESR). In the cytotoxicity test, 6-vinylubiquinone 5 and 6-(4′-fluorophenyl) ubiquinone 7 that possess half maximal inhibitory concentration value (IC50) of 6.1 μM and 6.2 μM. This would make them as valuable candidates for future pharmacological studies.
- Ma, Wei,Zhou, Hao,Ying, Yi-Lun,Li, Da-Wei,Chen, Guo-Rong,Long, Yi-Tao,Chen, Hong-Yuan
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experimental part
p. 5990 - 6000
(2011/09/19)
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- Reversible redox of NADH and NAD+ at a hybrid lipid bilayer membrane using ubiquinone
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Here, we report the reversible interconversion between NADH and NAD + at a low overpotential, which is in part mediated by ubiquinone embedded in a biomimetic membrane to mimic the initial stages of respiration. This system can be used as a platform to examine biologically relevant electroactive molecules embedded in a natural membrane environment and provide new insights into the mechanism of biological redox cycling.
- Ma, Wei,Li, Da-Wei,Sutherland, Todd C.,Li, Yang,Long, Yi-Tao,Chen, Hong-Yuan
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supporting information; experimental part
p. 12366 - 12369
(2011/10/02)
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- Single chain self-assembly of well-defined heterotelechelic polymers generated by ATRP and click chemistry revisited
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Well-defined heterotelechelic poly(styrene) carrying thymine/ diaminopyridine (DAP) (Mn,SEC = 9300, PDI = 1.04) and Hamilton wedge (HW)/cyanuric acid (CA) (Mn,SEC = 8200, PDI = 1.04) bonding motifs are prepared via a combination of controlled/living radical polymerization and copper catalyzed azide/alkyne "click" chemistry and are subsequently self-assembled as single chains to emulate-on a simple level-the self-folding behavior of natural biomacromolecules. Hydrogen nuclear magnetic resonance (1H NMR) in deuterated dichloromethane and dynamic light scattering analyses provides evidence for the hydrogen bonding interactions between the α-thymine and ω-DAP as well as α-CA and ω-HW chain ends of the heterotelechelic polymers leading to circular entropy driven single chain self-assembly. This study demonstrates that the choice of NMR solvent is important for obtaining well-resolved NMR spectra of the self-assembled structures. In addition, steric effects on the HW can affect the efficiency of the self-assembly process.
- Altintas, Ozcan,Rudolph, Tobias,Barner-Kowollik, Christopher
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experimental part
p. 2566 - 2576
(2012/03/27)
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- Synthesis and characterization of mitoQ and idebenone analogues as mediators of oxygen consumption in mitochondria
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Analogues of mitoQ and idebenone were synthesized to define the structural elements that support oxygen consumption in the mitochondrial respiratory chain. Eight analogues were prepared and fully characterized, then evaluated for their ability to support oxygen consumption in the mitochondrial respiratory chain. While oxygen consumption was strongly inhibited by mitoQ analogues 2-4 in a chain length-dependent manner, modification of idebenone by replacement of the quinone methoxy groups by methyl groups (analogues 6-8) reduced, but did not eliminate, oxygen consumption. Idebenone analogues 6-8 also displayed significant cytoprotective properties toward cultured mammalian cells in which glutathione had been depleted by treatment with diethyl maleate.
- Duveau, Damien Y.,Arce, Pablo M.,Schoenfeld, Robert A.,Raghav, Nidhi,Cortopassi, Gino A.,Hecht, Sidney M.
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experimental part
p. 6429 - 6441
(2010/10/03)
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- Design, synthesis, enzyme-inhibitory activity, and effect on human cancer cells of a novel series of jumonji domain-containing protein 2 histone demethylase inhibitors
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Selective inhibitors of Jumonji domain-containing protein (JMJD) histone demethylases are candidate anticancer agents as well as potential tools for elucidating the biological functions of JMJDs. On the basis of the crystal structure of JMJD2A and a homology model of JMJD2C, we designed and prepared a series of hydroxamate analogues bearing a tertiary amine. Enzyme assays using JMJD2C, JMJD2A, and prolyl hydroxylases revealed that hydroxamate analogue 8 is a potent and selective JMJD2 inhibitor, showing 500-fold greater JMJD2C-inhibitory activity and more than 9100-fold greater JMJD2C-selectivity compared with the lead compound N-oxalylglycine 2. Compounds 17 and 18, prodrugs of compound 8, each showed synergistic growth inhibition of cancer cells in combination with an inhibitor of lysine-specific demethylase 1 (LSD1). These findings suggest that combination treatment with JMJD2 inhibitors and LSD1 inhibitors may represent a novel strategy for anticancer chemotherapy.
- Hamada, Shohei,Suzuki, Takayoshi,Mino, Koshiki,Koseki, Koichi,Oehme, Felix,Flamme, Ingo,Ozasa, Hiroki,Itoh, Yukihiro,Ogasawara, Daisuke,Komaarashi, Haruka,Kato, Aiko,Tsumoto, Hiroki,Nakagawa, Hidehiko,Hasegawa, Makoto,Sasaki, Ryuzo,Mizukami, Tamio,Miyata, Naoki
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experimental part
p. 5629 - 5638
(2010/10/03)
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- From vesicles to solid spheres: Terminal functional group induced morphology modification
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Two similar naphthalimide based organogelators were synthesized. These two compounds can gelate a variety of organic solvents and form interesting morphologies. Transmission and scanning electron microscopy of the xerogels of the two compounds showed vesicle and solid sphere morphologies, respectively, even though their molecular structures are very close. The mechanism of the self-assembly process was investigated by 1H NMR, IR, 2D-NOESY spectra, wide-angle X-ray diffraction and rheological experiments. The study reveals that the cooperation and competition of multiple intra/inter-molecular interactions are the main determining factors for these compounds' self-assembly into vesicles and solid spheres. A single functional group able to determine the formation of vesicles in non-typical amphiphilic system is rarely encountered. Therefore, these results provide further insights into morphology control, especially the formation of vesicles in non-typical amphiphilic systems.
- Wang, Qi,Wu, Junchen,Gong, Zuguang,Zou, Ying,Yi, Tao,Huang, Chunhui
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scheme or table
p. 2679 - 2684
(2011/11/12)
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- Synthesis and biological evaluation of radioiodinated 2NUBTA as a cerebral ischemia marker
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N-[4-(Benzothiazol-2-yl)phenyl]-11-(2-nitroimidazole-1-yl)undecanamide (2NUBTA) was synthesized and radiolabeled with iodine-131. In vitro evaluation of the [131I]2NUBTA using murine sarcoma S180 cells showed increase in radioactivity in hypoxic cells up to 4 h, while it was not in aerobic cells. Its potential as a cerebral ischemia marker was evaluated using gerbil stroke models that had been subjected to right common carotid artery ligation to produce cerebral ischemia. The uptake in the right cerebral hemisphere decreased slowly than that of the left and the right/left hemisphere uptake ratios increased with time going on. It indicated that [131I]2NUBTA might be a possible cerebral ischemia marker.
- Chu, Taiwei,Li, Zejun,Wang, Xiangyun
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experimental part
p. 658 - 661
(2009/09/06)
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- Double ordered layers within mierophase-separated lamellar structure of double liquid crystalline side-chain type block copolymer
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A new hierarchical nanostructure was created by self-assembly of a double liquid crystalline side-chain type block copolymer. The block copolymer was successfully prepared via a nitro-xide-mediated living free radical polymerization and formed double ordered layers within a phase-separated lamellar structure of the cast film. Copyright
- Maeda, Rina,Hayakawa, Teruaki,Tokita, Masatoshi,Kakimoto, Masa-Aki,Urushibata, Hiroaki
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supporting information; experimental part
p. 1174 - 1175
(2011/02/28)
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