17974-77-5Relevant articles and documents
Chemical synthesis of 7α-hydroxycholest-4-en-3-one, a biomarker for irritable bowel syndrome and bile acid malabsorption
Offei, Samuel D.,Arman, Hadi D.,Yoshimoto, Francis K.
, (2019)
7α-Hydroxy-cholest-4-en-3-one is a biomarker for bile acid loss, irritable bowel syndrome, and other diseases associated with defective bile acid biosynthesis. Furthermore, 7α-hydroxy-cholest-4-en-3-one is the physiological substrate for cytochrome P450 8B1 (P450 8B1 or CYP8B1), the oxysterol 12α-hydroxylase enzyme implicated in obesity and cardiovascular health. We report the chemical synthesis of this physiologically important oxysterol beginning with cholesterol. The key feature of this synthesis involves a regioselective C3-allylic oxidation of a 3-desoxy-Δ4-7α-formate steroid precursor to form 7α-formyloxy-cholest-4-en-3-one, which was saponified to yield 7α-hydroxy-cholest-4-en-3-one.
J-based analysis and DFT-NMR assignments of natural complex molecules: Application to 3β,7-dihydroxy-5,6-epoxycholestanes
Poza, Jesus Javier,Jimenez, Carlos,Rodriguez, Jaime
, p. 3960 - 3969 (2008)
In order to reproduce the stereochemical dispositions of the epoxy and hydroxy functionalities, four 3β,7-hydroxy-5,6-epoxycholestanes were easily prepared from cholesterol, and their NMR spectroscopic data were experimentally obtained from 1D and 2D NMR experiments. An exhaustive QM-J-based analysis was then performed to replicate the experimental H-H and C-H coupling constants as well as the 13C NMR chemical shifts. The B3LYP GIAO methodology with the 6-311-G(d,p) basis set was chosen and showed that the data obtained from rings A and B were sufficient to calculate the correct stereochemistry of the 5,6-epoxy and 7-hydroxy groups. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Selective reduction of α,β-unsaturated steroidal carbonyl compounds by NaBH4in presence of guanidine hydrochloride in dioxane
Khan, Salman Ahmad,Asiri, Abdullah M.
, p. 6331 - 6334 (2014)
A selective hydrogenation of α,β-unsaturated steroidal carbonyl compounds with NaBH4in the presence of guanidine hydrochloride in dioxane in good to excellent yields are described.
Novel synthesis strategy for the preparation of individual phytosterol oxides
Gao, Junlan,Yue, Qiulin,Ji, Yishun,Cheng, Beijiu,Zhang, Xin
, p. 982 - 988 (2013)
Sterols (cholesterol and phytosterols) are important structural components of cell membranes and major constituents of lipid metabolism. Research on their oxides, such as the factors affecting oxidation, oxides' structures, and qualitative and quantitative analysis, aroused more attention in this decade. However, the biological roles of individual phytosterol oxides are still unclear because no commercial individual phytosterol oxide standards are available. Different from the traditional chemical synthesis, in the present study, chemical synthesis from a starting phytosterol mixture followed with a semipreparative HPLC separation produced individual oxides. TLC and analytical HPLC were used here to not only monitor the reaction process but also specifically analyze the synthetic intermediates and oxides. The chromatographic results exhibited strict rules and similar characteristics. Finally, for the first time, four individual phytosterol oxides were successfully separated and collected by a semipreparative HPLC system, thus providing a novel strategy for the preparation of individual phytosterol oxides.
Metal-Free Allylic Oxidation of Steroids Using TBAI/TBHP Organocatalytic Protocol
Lam, Ying-Pong,Yeung, Ying-Yeung
supporting information, p. 2369 - 2372 (2018/04/19)
A mild, efficient and organocatalytic allylic oxidation of steroids using a TBAI/TBHP protocol has been developed. A range of bioactive Δ5-en-7-ones can be easily prepared from the corresponding Δ5-steroids. The methodology features several advantages, including readily available starting materials, environmentally benign oxidant, high functional group compatibility, and metal-free catalysis.
NANOEMULSIONS AND METHODS FOR CANCER THERAPY
-
, (2017/12/15)
An oxysterol or oxysterol-like compound is provided, which finds use in treating and/or targeting cancer.
Oxysterols: Synthesis and anti-leishmanial activities
Ghosh, Pranab,Ghosh, Ashim,Mandal, Amitava,Sultana, Sirin Salma,Dey, Somaditya,Pal, Chiranjib
, p. 65 - 73 (2016/03/04)
Oxygenated sterols (2-16) were synthesized by skeletal rearrangement of steroidal allylic alcohols. All the derivatives were screened for their anti-leishmanial activities. Compounds 3, 11 and 12 showed potent activities. Compound 12 was found least toxic and induced highest nitric oxide (NO) at 48 h. Least toxicity of compound 12 on splenocytes validated its best anti-amastigote effect and induction of NO.
Synthesis of 7-dehydrocholesterol through hexacarbonyl molybdenum catalyzed elimination reaction
Ur Rahman, Faiz,Tan, Tian Wei
experimental part, p. 247 - 254 (2012/05/05)
The efficiency of hexacarbonyl molybdenum catalyzed elimination reaction of the allylic acetates has been improved by the presence of O,N- bis(trimethylsilyl) acetamide in the reaction medium. The methodology is particularly well employed for the elimination of 7-acetoxycholesterol-3- acetate(cholestrol-3,7-diacetate) for which the resulting product obtained was exclusively 5,7-homoannular diene(7-dehydrocholesterol-3-acetate). Good yield is achieved (up to 70 %) while decreasing the side products formation and reducing the costs as compared to the previously used procedures. Hexacarbonyl molybdenum elimination reaction is greatly influenced by the reaction temperature, at low as well as at high temperature low yield of the homoannular diene product is separated while at moderate conditions of temperature high products formation is observed.
Sterols as anticancer agents: Synthesis of ring-B oxygenated steroids, cytotoxic profile, and comprehensive SAR analysis
Carvalho, Jo?o F. S.,Silva, M. Manuel Cruz,Moreira, Jo?o N.,Sim?es, Sérgio,Sá E Melo, M. Luisa
supporting information; experimental part, p. 7632 - 7638 (2011/02/21)
The cytotoxicity of oxysterols was systematically studied in tumor and normal cells. Synthetic strategies to prepare this library included oxidations at ring B and a new method to yield 6β-hemiphthalates directly from Δ5-steroids. Most oxysterols were cytotoxic and showed selectivity toward cancer cells, LAMA-84 cells (leukemia) being particularly sensitive to 4, 8, 22, and 27 (IC50 5.6 μM). The structural requirements to induce selective toxicity are discussed to shed light on the development of new anticancer drugs.
Efficient chemoenzymatic synthesis, cytotoxic evaluation, and SAR of epoxysterols
Carvalho, Jo?o F. S.,Cruz Silva, M. Manuel,Moreira, Jo?o N.,Sim?es, Sérgio,Sá E Melo, M. Luisa
experimental part, p. 4007 - 4019 (2009/12/26)
A library of diastereomerically pure epoxysterols, prepared by combining chemical and enzymatic methodologies, was evaluated for cytotoxicity toward human cancer and noncancer cell lines. Unsaturated steroids were oxidized by magnesium bis(monoperoxyphthalate) hexahydrate in acetonitrile, and the resulting epimeric epoxides were enzymatically separated using Novozym 435 or lipase AY. Some of the synthesized epoxysterols have potent cytotoxicity and higher activity on cancer cell lines HT29 and LAMA-84.
