- Novel Nanocarrier Platform for Effective Treatment of Visceral Leishmaniasis
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Leishmaniasis is among the five parasitic diseases that still require the development of new drugs. Ultrasmall cerium (Ce3/4+) cation-doped maghemite (?3-Fe2O3) nanoparticles (NPs) were tested as a potential drug to treat visceral leishmaniasis, a disease affecting millions of people worldwide. The NPs were engineered for binding a polycationic branched polyethylenimine (PEI) polymer, thereby rupturing the single lysosome of these parasites and enabling entry of the anti-Leishmania drug, pentamidine. Exploiting the known lanthanide cation/complex-based coordinative chemical reactivity enabled the binding of both active agents onto the surface of the NPs. To optimize the fabrication of the cytotoxic NPs, optimization via a DoE (Design of Experiments) process was used to identify the optimal NP with toxicity against the two stages of the parasite, promastigotes, which propagate in the insect, and amastigotes, which infect the mammalian host. The screen identified a single optimized NP (DoE Opt) that was further examined in a mouse model of visceral leishmaniasis. Intravenous injection of the NPs had no adverse effects on the cellular composition or biochemical parameters of the blood, demonstrating no signs of systemic toxicity. The optimized NP was able to eradicate visceral disease caused by Leishmania donovani infection. The study demonstrates the versatile ability of the cerium-doped NPs to bind at least two cytotoxic ligands. This approach could be used for optimizing the binding of different drugs for the treatment of other diseases, including cancer. Since resistance to treatment with nanocarriers was not reported to date, such an approach could potentially overcome drug resistance that emerges when using soluble small molecule drugs.
- Harel, Yifat,Israel, Liron Limor,Kannan, Sriram,Lellouche, Emmanuel,Lellouche, Jean-Paul,Michaeli, Shulamit,Tsubery, Merav Nadav,Varvak, Alexander
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p. 2327 - 2341
(2021/11/13)
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- Structure-Activity Studies with Bis-Amidines That Potentiate Gram-Positive Specific Antibiotics against Gram-Negative Pathogens
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Pentamidine, an FDA-approved antiparasitic drug, was recently identified as an outer membrane disrupting synergist that potentiates erythromycin, rifampicin, and novobiocin against Gram-negative bacteria. The same study also described a preliminary structure-activity relationship using commercially available pentamidine analogues. We here report the design, synthesis, and evaluation of a broader panel of bis-amidines inspired by pentamidine. The present study both validates the previously observed synergistic activity reported for pentamidine, while further assessing the capacity for structurally similar bis-amidines to also potentiate Gram-positive specific antibiotics against Gram-negative pathogens. Among the bis-amidines prepared, a number of them were found to exhibit synergistic activity greater than pentamidine. These synergists were shown to effectively potentiate the activity of Gram-positive specific antibiotics against multiple Gram-negative pathogens such as Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli, including polymyxin- and carbapenem-resistant strains.
- Wesseling, Charlotte M. J.,Slingerland, Cornelis J.,Veraar, Shanice,Lok, Samantha,Martin, Nathaniel I.
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p. 3314 - 3335
(2021/11/24)
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- Discovery of decamidine as a new and potent PRMT1 inhibitor
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Protein arginine methyltransferase 1 (PRMT1) is a key player for the dynamic regulation of arginine methylation. Its dysregulation and aberrant expression are implicated in various pathological conditions, and a plethora of evidence suggests that PRMT1 inhibition is of significant therapeutic value. Herein, we reported the modification of a series of diamidine compounds with varied lengths in the middle alkyl linker for PRMT1 inhibition. Decamidine (2j), which possesses the longest linker in the series, displayed 2- and 4-fold increase in PRMT1 inhibition (IC50 = 13 μM), compared with furamidine and stilbamidine. The inhibitory activity toward PRMT1 was validated by secondary orthogonal assays. Docking studies showed that the increased activity is due to the extra interaction of the amidine group with the SAM binding pocket, which is absent when the linker is not long enough. These results provide structural insights into developing the amidine type of PRMT1 inhibitors.
- Zhang, Jing,Qian, Kun,Yan, Chunli,He, Maomao,Jassim, Brenson A.,Ivanov, Ivaylo,Zheng, Yujun George
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supporting information
p. 440 - 444
(2017/03/08)
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- Small Molecule Inhibitors of Ca2+-S100B Reveal Two Protein Conformations
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The drug pentamidine inhibits calcium-dependent complex formation with p53 (CaS100B·p53) in malignant melanoma (MM) and restores p53 tumor suppressor activity in vivo. However, off-target effects associated with this drug were problematic in MM patients. Structure-activity relationship (SAR) studies were therefore completed here with 23 pentamidine analogues, and X-ray structures of CaS100B·inhibitor complexes revealed that the C-terminus of S100B adopts two different conformations, with location of Phe87 and Phe88 being the distinguishing feature and termed the "FF-gate". For symmetric pentamidine analogues (CaS100B·5a, CaS100B·6b) a channel between sites 1 and 2 on S100B was occluded by residue Phe88, but for an asymmetric pentamidine analogue (CaS100B·17), this same channel was open. The CaS100B·17 structure illustrates, for the first time, a pentamidine analog capable of binding the "open" form of the "FF-gate" and provides a means to block all three "hot spots" on CaS100B, which will impact next generation CaS100B·p53 inhibitor design.
- Cavalier, Michael C.,Ansari, Mohd. Imran,Pierce, Adam D.,Wilder, Paul T.,McKnight, Laura E.,Raman, E. Prabhu,Neau, David B.,Bezawada, Padmavani,Alasady, Milad J.,Charpentier, Thomas H.,Varney, Kristen M.,Toth, Eric A.,MacKerell, Alexander D.,Coop, Andrew,Weber, David J.
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p. 592 - 608
(2016/02/09)
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- Synthesis and biological evaluation of l-valine-amidoximeesters as double prodrugs of amidines
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In general, drugs containing amidines suffer from poor oral bioavailability and are often converted into amidoxime prodrugs to overcome low uptake from the gastrointestinal tract. The esterification of amidoximes with amino acids represents a newly developed double prodrug principle creating derivatives of amidines with both improved oral availability and water solubility. N-valoxybenzamidine (1) is a model compound for this principle, which has been transferred to the antiprotozoic drug pentamidine (8). Prodrug activation depends on esterases and mARC and is thus independent from activation by P450 enzymes. Therefore, drug-drug interactions or side effects will be minimized. The synthesis of these two compounds was established, and their biotransformation was studied in vitro and in vivo. Bioactivation of N-valoxybenzamidine (1) and N,N′-bis(valoxy)pentamidine (7) via hydrolysis and reduction has been demonstrated in vitro with porcine and human subcellular enzyme preparations and the mitochondrial Amidoxime Reducing Component (mARC). Moreover, activation of N-valoxybenzamidine (1) by porcine hepatocytes was studied. In vivo, the bioavailability in rats after oral application of N-valoxybenzamidine (1) was about 88%. Similarly, N,N′-bis(valoxy) pentamidine (7) showed oral bioavailability. Analysis of tissue samples revealed high concentrations of pentamidine (8) in liver and kidney.
- Kotthaus, Joscha,Hungeling, Helen,Reeh, Christiane,Kotthaus, Jürke,Schade, Dennis,Wein, Silvia,Wolffram, Siegfried,Clement, Bernd
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p. 1907 - 1914
(2011/05/05)
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- The fourth molybdenum containing enzyme mARC: Cloning and involvement in the activation of N-hydroxylated prodrugs
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The recently discovered mammalian molybdoprotein mARC1 is capable of reducing N-hydroxylated compounds. Upon reconstitution with cytochrome b 5 and b5 reductase, benzamidoxime, pentamidine, and diminazene amidoximes, N-hydroxymelagatran, guanoxabenz, and N-hydroxydebrisoquine are efficiently reduced. These substances are amidoxime/N-hydroxyguanidine prodrugs, leading to improved bioavailability compared to the active amidines/guanidines. Thus, the recombinant enzyme allows prediction about in vivo reduction of N-hydroxylated prodrugs. Furthermore, the prodrug principle is not dependent on cytochrome P450 enzymes.
- Gruenewald, Sanja,Wahl, Bettina,Bittner, Florian,Hungeling, Helen,Kanzow, Stephanie,Kotthaus, Joscha,Schwering, Ulrike,Mendel, Ralf R.,Clement, Bernd
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scheme or table
p. 8173 - 8177
(2009/12/07)
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- Analogues of 1,5-bis(4-amidinophenoxy)pentane (pentamidine) in the treatment of experimental Pneumocystis carinii pneumonia
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A series of 33 analogues of the anti-Pneumocystis carinii drug 1,5-bis(4-amidinophenoxy)pentane (pentamidine) was synthesized for screening against a rat model of P. carinii pneumonia (PCP). Twenty-five of the compounds showed efficacy against PCP when compared to a saline-treated control group. Two compounds, 1,4-bis(4-amidinophenoxy)butane (butamidine, 6) and 1,3-bis(4-amidino-2-methoxyphenoxy)propane (DAMP, 16), were statistically more effective than the parent drug in treating PCP in the rat model of infection. In addition to their activity against PCP, the compounds were also evaluated for antitrypsin activity, ability to inhibit thymidylate synthetase, affinity for DNA, and toxicity. No correlation was observed between the tested molecular interactions of the diamidines and their effectiveness against PCP.
- Tidwell,Jones,Geratz,Ohemeng,Cory,Hall
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p. 1252 - 1257
(2007/10/02)
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