- Base-free oxidation of alcohols enabled by nickel(ii)-catalyzed transfer dehydrogenation
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An efficient nickel(ii)-catalyzed transfer dehydrogenation oxidation of alcohols is reported that relies on cyclohexanone as the formal oxidant and does not require the use of an external base. The synthetic utility of this protocol is demonstratedviathe facile oxidation of structurally complicated natural products.
- Ye, Danfeng,Liu, Zhiyuan,Sessler, Jonathan L.,Lei, Chuanhu
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supporting information
p. 11811 - 11814
(2020/10/13)
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- Synthesis and search for 3β,3′β-disteryl ethers after high-temperature treatment of sterol-rich samples
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It has been proven that at increased temperature, sterols can undergo various chemical reactions e.g., oxidation, dehydrogenation, dehydration and polymerisation. The objectives of this study are to prove the existence of dimers and to quantitatively analyse the dimers (3β,3′β-disteryl ethers). Sterol-rich samples were heated at 180 °C, 200 °C and 220 °C for 1 to 5 h. Quantitative analyses of the 3β,3′β-disteryl ethers were conducted using liquid extraction, solid-phase extraction and gas chromatography coupled with mass spectrometry. Additionally, for the analyses, suitable standards were synthetized from native sterols. To identify the mechanism of 3β,3′β-disteryl ether formation at high temperatures, an attempt was made to use the proposed synthesis method. Additionally, due to the association of sterols and sterol derivatives with atherosclerosis, preliminary studies with synthetized 3β,3′β-disteryl ethers on endothelial cells were conducted.
- Bus, Katarzyna,Ofiara, Karol,Sitkowski, Jerzy,Szterk, Arkadiusz,Zmys?owski, Adam
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- Antiangiogenic brassinosteroid compounds
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A method of treating a solid tumor in a mammal by inhibiting angiogenesis, including administering to the mammal which has a solid tumor selected from the group consisting of breast carcinoma, lung carcinoma, prostate carcinoma, colon carcinoma, ovarian carcinoma, neuroblastoma, central nervous system tumor, multiform glioblastoma and melanoma; a composition including brassinosteroids of general formula (I) wherein can be a single or double bond and the configurations of carbon atoms C22 and C23 respectively linked to the substituents HO are S for both carbon atoms and a pharmaceutically acceptable additive.
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Page/Page column 7
(2015/12/04)
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- Pincer and diamine Ru and Os diphosphane complexes as efficient catalysts for the dehydrogenation of alcohols to ketones
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The ruthenium and osmium complexes [MCl2(diphosphane)(L)] (M=Ru, Os; L=bidentate amino ligand) and [MCl(CNN)(dppb)] (CNN=pincer ligand; dppb=1,4-bis- (diphenylphosphino)butane), containing the N-H moiety, have been found to catalyze the acceptorless dehydrogenation of alcohols in tBuOH and in the presence of KOtBu. The compounds trans-[MCl2(dppf)(en)] (M=Ru 7, Os 13; dppf=1,1′-bis(diphenylphosphino)ferrocene; en=ethylenediamine) display very high activity and different substrates, including cyclic and linear alcohols, are efficiently oxidized to ketones by using 0.8-0.04mol% of catalyst. The effect of the base and the comparison of the catalytic activity of the Ru versus Os complexes are reported. The ruthenium complex 7 generally leads to a faster conversion into ketones with respect to the osmium complex 13, which displays better activity in the dehydrogenation of 5-en-3β-hydroxy steroids. The synthesis of new Ru and Os complexes [MCl2(PP)(L)] (PP=dppb, dppf; L=(±)-trans-1,2-diaminocyclohexane, 2-(aminomethyl) pyridine, and 2-aminoethanol) of trans and cis configuration is also reported. Alcohol breakdown: Ruthenium and osmium phosphane complexes containing nitrogen ligands with the N-H functionality efficiently catalyze the acceptorless dehydrogenation of alcohols. With [MCl2(dppf)(en)] (M=Ru, Os; dppf=1,1′-bis(diphenylphosphino)ferrocene; en=ethylenediamine) in the presence of KOtBu several alcohols have been converted into ketones (see scheme), including sterols for which Os displays a better activity than Ru. Copyright
- Baratta, Walter,Bossi, Gianluca,Putignano, Elisabetta,Rigo, Pierluigi
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experimental part
p. 3474 - 3481
(2011/05/02)
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- Quantitative structure inter-activity relationship (QSInAR). Cytotoxicity study of some hemisynthetic and isolated natural steroids and precursors on human fibrosarcoma cells HT1080
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Combined experimental and quantitative structure inter-activity relationship (QSIAR) computation methods were advanced in order to establish the structural and mechanistic influences that steroids and triterpenes, either as newly synthesized or naturally isolated products, have on human HT1080 mammalian cancer cells. The main Hansch structural indicators such as hydrophobicity (LogP), polarizability (POL) and total energy (Etot) were considered and both the structure-projected as well as globally computed correlations were reported; while the inter-activity correlation of the global activity with those projected on structural information was revealed as equal to the direct structural-activity one for the trial sets of compounds, the prediction for the testing set of molecules reported even superior performances respecting those characteristic for the calibration set, validating therefore the present QSInAR models; accordingly, it follows that the LogP carries the most part of the cytotoxic signal, while POL has little influence on inhibiting tumor growth-A complementary behavior with their earlier known influence on genotoxic carcinogenesis. Regarding the newly hemisynthetic compounds it was found that stigmasta-4,22-dien-3-one is not adapted for cell membrane diffusion; it is recommended that aminocinnamyl chlorohydrate be further modified in order to acquire better steric influence, while aminocinnamyl-2,3,4,6-O- tetraacetyl-a-D-glucopyranoside was identified as being inhibited in the tumor cell by other molecular mechanisms-here not revealed-although it has a moderate-high anti-cancer structurally predicted activity.
- Putz, Mihai V.,Lazea, Marius,Sandjo, Louis P.
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scheme or table
p. 6603 - 6620
(2011/11/12)
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- COMPOUND SHOWING ANTI-INFLAMMATORY ACTIVITY AND ANTIVIRAL ACTIVITY, PHARMACEUTICAL COMPOSITIONS COMPRISING THE SAME, A PROCESS FOR OBTAINING THE SAME AND USE OF THE SAME IN THE TREATMENT OF EPIDEMIC KERATOCONJUNCTIVITES AND HERPETIC STROMAL KERATIS
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The present invention refers to a compound having anti-inflammatory and antiviral activity according to the following structural formula: wherein, R1 and R3 are selected from H, HO—, R5—O—, HCOO—, R5—COO—, —OOC—R6—COO—, p-toluene sulphonate, phosphate, tartrate, maleate, sulphate, fluorine, chlorine, bromine, iodine and methanesulphonate,R2 is selected from H, HO—, R5—O—, HCOO—, R5—COO—, —OOC—R6—COO—, p-toluene sulphonate, phosphate, tartrate, maleate, sulphate, fluorine, chlorine, bromine, and iodine,or —R1 and —R2 can be together —O—, (CH3)2—(CO)2-(ó-(CH3—CH2)2—(CO)2—R4 and R5 are selected from H and linear or branched C1-C4 alkyl,R6 is —(CH2)n equals to 1, 2 ó 3, and, can be a single bond or double bond, to the pharmaceutical compositions comprising the same, to a process for preparing the same and to the use of the same for preparing pharmaceutical compositions. Particularly, the compounds of the invention are particularly useful for preparing ophthalmic pharmaceuticals for the treatment of diseases caused by adenovirus and preferably, epidemic keratoconjunctivitis. Also, the compounds of the invention are particularly useful for preparing ophthalmic pharmaceuticals for the treatment of diseases caused by the herpes simplex type 1 (HSV-1) and preferably, herpetic stromal keratitis (HK).
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Page/Page column 4
(2010/06/11)
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- Synthesis and evaluation of some steroidal oximes as cytotoxic agents: Structure/activity studies (I)
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The side chain of a compound plays an important role in its biological function. In our studies, we have found that hydroximinosteroid derivatives with different side chains and position of hydroximino on ring A and B displayed remarkable distinct cytotoxicities against a diversity of cancer cell types. Presence of an oxime group on ring B and a hydroxy on ring A or B resulted in a higher cytotoxicity than other structural motifs. In addition, a cholesterol-type side chain at position 17 was required for the biological activity. Our findings provide new evidence showing the relationship between the chemical structure and biological function. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs.
- Cui, Jian-Guo,Fan, Lei,Huang, Li-Liang,Liu, Hong-Li,Zhou, Ai-Min
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experimental part
p. 62 - 72
(2009/04/10)
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- Structure and synthesis of a progesterone homologue from the skin of the dorid nudibranch Aldisa smaragdina
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The short-side-chain steroid 24-norchol-4-ene-3,22-done (6) has been found to be the main metabolite of both skin and mucus of the mollusc Aldisa smaragdina. This compound, previously reported as a microbial degradation product of cholesterol, has never previously been isolated from natural sources. The absolute stereochemistry was determined by synthesis from commercial stigmasterol, and a full NMR characterisation is also reported. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Gavagnin, Margherita,Ungur, Nicon,Mollo, Ernesto,Templado, Jose,Cimino, Guido
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p. 1500 - 1504
(2007/10/03)
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- The synthesis of spermine analogs of the shark aminosterol squalamine
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Aminosterols isolated from the dogfish shark Squalus acanthias are promising therapeutic agents in the treatment of infection and cancer. One of these, MSI-1436, has been shown to possess antimicrobial activity slightly better than squalamine. In this stu
- Shu, Youheng,Jones, Stephen R,Kinney, William A,Selinsky, Barry S
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p. 291 - 304
(2007/10/03)
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- Methods and compositions for attracting and controlling termites
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The present invention provides a composition for attracting termites containing a steroid derivative of formula I The present invention also provides a method for attracting or controlling termites with the composition.
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- Methods and compositions for attracting and controlling termites
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The present invention provides a composition for attracting termites containing a steroid derivative of formula I The present invention also provides a method for attracting or controlling termites with the composition.
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- Stereospecific oxidation of 3β-hydroxysteroids by persolvent fermentation with Pseudomonas sp. ST-200
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Pseudomonas sp. strain ST-200 isolated from a humus soil effectively oxidizes cholesterol dissolved in organic solvents but not that suspended in the growth medium. The organism does not assimilate cholesterol. This organism oxidized a variety of 5α- or 5-ene-steroids dissolved in organic solvent. First, the 3β-OH group was oxidized to a ketone group. The 3α-OH group was scarcely oxidized. Successively, C-6 position of 5-ene-steroids was hydroxylated, and a double bond of 5-ene-steroids was transferred from Δ5 to Δ4. Then, the 6-OH group was oxidized to a ketone group. Persolvent fermentation with ST-200 would provide an effective, convenient, and stereospecific method to oxidize the C-3 and C-6 positions of steroids.
- Aono, Rikizo,Doukyu, Noriyuki
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p. 1146 - 1151
(2007/10/03)
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- Ruthenium-catalyzed Oppenauer-type oxidation of 3β-hydroxy steroids. A highly efficient entry into the steroidal hormones with 4-en-3-one functionality
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Oxidation of 5-unsaturated 3β-hydroxy steroids 1 to the corresponding 4-en-3-one derivatives 2 can be performed efficiently by acetone at reflux in the presence of a catalytic system consisting of either (PPh3)3RuCl2 (3) and K2CO3 or [(C4Ph4COHOCC4Ph4)(μ-H)][(CO)4Ru2] (4). The reaction proceeds via a ruthenium-catalyzed dehydrogenation of 1 and subsequent hydrogen transfer to acetone with concomitant double bond migration.
- Almeida, Maria L. S.,Kocǒvsky, Pavel,Báckvall, Jan-E?.
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p. 6587 - 6590
(2007/10/03)
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- Microbial transformation of β-sitosterol and stigmasterol into 26-oxygenated derivatives
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The genetically modified Mycobacterium sp. BCS 396 strain has been used to transform sterols with stigmastane side chain in order to obtain 26-oxidized metabolites. β-Sitosterol (I) was transformed to 4-stigmasten-3-one (II), 26-hydroxy-4-stigmasten-3-one (III), and 3-oxo-4-stigmasten-26-oic acid (IV), while stigmasterol (V) was converted to 4,22-stigmastadien-3-one (VI), 6β-hydroxy-4,22-stigmastadien-3-one (VII), 26-hydroxy-4,22-stigmastadien-3-one (VIII), 3-oxo-4,22-stigmastadien-26-oic acid methyl ester (IX), and 3-oxo-1,4,22-stigmastatrien-26-oic acid methyl ester (X) with that strain. In both β-sitosterol and stigmasterol, 26-oxidation generates the R-configuration on C-25.
- Ambrus, Gabor
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p. 621 - 625
(2007/10/02)
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- TERPENOIDS AND STEROLS FROM THE WOOD OF ABIES PINSAPO
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From the neutral fraction of the hexane extract of the wood of Abies pinsapo 11 sesquiterpenoids, seven diterpenoids, three triterpenoids and two sterols have been identified.Three of them are new natural products: 3β-hydroxy-13-epimanool, (23R,25R)-3α-methoxy-9,19-cyclo-9β-lanostan-26,23-olide and (22S)-5α-ergostane-3α,22-diol.Their structure were established by spectroscopic methods and chemical correlations. Key words: Abies pinsapo; Pinaceae; wood; labdane diterpenoids; cyclolanostanolides; sterols.
- Barrero, Alejandro,Sanchez, Juan F.,Alvarez-Manzaneda, E. J.,Dorado, M. Munoz,Haidour, Ali
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p. 1261 - 1266
(2007/10/02)
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- Synthesis of 6-Deoxohomodolichosterone, a New Plant-growth-promoting Steroid
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6-Deoxohomodolichosterone (1), a new member of the brassinosteroid family, was synthesized in twelve steps from stigmasterol (4).Birch reduction of the dienone (5) gave directly 5α-stigmast-22-en-3β-ol (6), the mesylate of which was treated with lithium bromide in refluxing dimethylformamide.Selective oxidation of the 2-ene function of the resulting 2,22-diene (7), followed by acetonide formation, provided the acetonide 22-alkene (8).Epoxide-ring opening of the (22R,23R)-epoxide (9), derived from (8), with phenylselenolate anion, treatment with 30percent hydrogen peroxide, and epoxidation with peracid afforded the 22-hydroxy-23,24-epoxide (15).Ready cleavage of the epoxide ring of compound (15) with aluminium isopropoxide and deprotection yielded 6-deoxohomodolichosterone (1).
- Takatsuto, Suguru,Ikekawa, Nobuo
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p. 2269 - 2272
(2007/10/02)
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