114246-94-5Relevant articles and documents
Manganese (III) acetate dihydrate catalyzed aerobic epoxidation of unfunctionalized olefins in fluorous solvents
Ravikumar,Barbier, Francis,Begue, Jean-Pierre,Bonnet-Delpon, Daniele
, p. 7457 - 7464 (1998)
Manganese(III) acetate dihydrate is used as a catalyst for the epoxidation of various olefins with molecular oxygen/pivalaldehyde as an oxidant in perfluoro-2-butyltelrahydrofuran. Various types of olefins, including substituted styrenea, stilbenes and cyclic and acyclic alkenes were epoxidized in excellent yields at 25°C. The reaction is stereodependent. Regioselectivity is observed on epoxidation of limonene. Mono- and disubstituted olefins show interesting dichotomy in their reactivity in fluorous solvents such as perfluoro-2-butyltetrahydrofuran and 1,1,1,3,3,3- hexafluoro-2-propanol.
β-Selective Epoxidation of Cholesterol Derivatives with Molecular Oxygen and Aldehyde Catalyzed by Manganese(II) Complex
Yamada, Tohru,Imagawa, Kiyomi,Mukaiyama, Teruaki
, p. 2109 - 2112 (1992)
In the presence of catalytic amount of bis(dipivaloylmethanato)manganese(II) (= Mn(dpm)2), various cholesterol derivatives are smoothly converted into the corresponding β-epoxides in good to high yields with combined use of molecular oxygen and isobutyraldehyde.These stereoselectivities are the reversal of the cases using peracid such as mCPBA.
Solvent-free synthesis of 6β-phenylamino-cholestan-3β,5α-diol and (25R)-6β-phenylaminospirostan-3β,5α-diol as potential antiproliferative agents
Soto-Castro, Delia,Lara Contreras, Roberto Carlos,Pina-Canseco, María,Santillán, Rosa,Hernández-Huerta, María Teresa,Negrón Silva, Guillermo E.,Pérez-Campos, Eduardo,Rincón, Susana
, p. 92 - 100 (2017)
In this paper is described a synthetic route to 6β-phenylamino-cholestan-3β,5α-diol and (25R)-6β-phenylaminospirostan-3β,5α-diol, starting from cholesterol and diosgenin, respectively. The products were obtained in two steps by epoxidation followed by aminolysis, through an environmentally friendly and solvent-free method mediated by SZ (sulfated zirconia) as catalyst. The use of SZ allows chemo- and regioselective ring opening of the 5,6α-epoxide during the aminolysis reaction eliminating the required separation of the epoxide mixture. The products obtained were spectroscopically characterized by 1H, PENDANT 13C NMR and HETCOR experiments, and complemented with FTIR-ATR and HRMS. The antiproliferative effect of the β-aminoalcohols was evaluated on MCF-7 cells after 48 h of incubation, by MTT and CVS assays. These methodologies showed that both compounds have antiproliferative activity, being more active the cholesterol analogue. Additionally, the cell images obtained by Harris’ Hematoxylin and Eosin (H&E) staining protocol, evidenced formation of apoptotic bodies due to the presence of the obtained β-aminoalcohols in a dose-dependent manner.
Molybdenum catalyzed β-selective epoxidation of cholesterol esters with molecular oxygen
Kantam,Santhi
, p. 961 - 964 (1994)
Molybdenyl(IV) acetylacetonate catalyses the conversion of various cholesterol esters into the corresponding β-epoxides in good yields with the combined use of molecular oxygen and i-butyraldehyde at room temperature.
Oxidation of Cholesterol by Heating
Osada, Kyoichi,Kodama, Takehiro,Yamada, Koji,Sugano, Michihiro
, p. 1198 - 1202 (1993)
Oxidation of pure cholesterol during heating in an air oven at high temperature was studied.Cholesterol was virtually stable during heating at 100 deg C for 24 h but was unstable at temperature above 120 deg C.In the heated choleaterol preparations, a number of oxidized derivatives were detected by a combination of thin-layer chromatography and capillary gas chromatography-mass spectrometry.Major oxidized sterols were 7α-hydroxycholesterol, 7β-hydroxycholesterol, 5α-epoxycholesterol, 5β-epoxycholesterol, cholestanetriol, and 7-ketocholesterol.Various oxidized cholesterol derivatives were produced during heating above 120 deg C within a relatively short time (1h).The composition of the oxidized products differed depending on temperature and time of heating.When cholesterol was heated at 150 deg C, the production of oxidized cholesterol was maximum, and 7-ketocholesterol was the most predominant oxidized product.Heating at 120 deg C also produced oxidized cholesterol to some extent, whereas only marginal amounts of oxidized cholesterols were produced at 100 deg C and at 200 deg C cholesterol was almost decomposed in a short time.
Biosynthesis of 20-hydroxyecdysone in plants: 3β-Hydroxy-5β-cholestan-6-one as an intermediate immediately after cholesterol in Ajuga hairy roots
Fujimoto, Yoshinori,Maeda, Izumi,Ohyama, Kiyoshi,Hikiba, Juri,Kataoka, Hiroshi
, p. 59 - 64 (2015)
3β-Hydroxy-5β-cholestan-6-one was identified in the EtOAc extract of Ajuga hairy roots by micro-analysis using LC-MS/MS in the multiple reaction mode (MRM). Furthermore, administration of (2,2,4,4,7,7-2H6)- and (2,2,4,4,6,7,7-2H7)-cholesterols to the hairy roots followed by LC-MS/MS analysis of the EtOAc extract of the hairy roots indicated that cholesterol was converted to the 5β-ketone with hydrogen migration from the C-6 to the C-5 position. These findings, in conjunction with the previous observation that the ketone was efficiently converted to 20-hydroxyecdysone, strongly suggest that the 5β-ketone is an intermediate immediately formed after cholesterol during 20-hydroxyecdysone biosynthesis in Ajuga sp. In addition, the mechanism of the 5β-ketone formation from cholesterol is discussed.
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
, p. 4007 - 4019 (2009)
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.
Effect of Eleven Antioxidants in Inhibiting Thermal Oxidation of Cholesterol
Xu, Guihua,Liu, Donghong,Zhao, Gongling,Chen, Shiguo,Wang, Jun,Ye, Xingqian
, p. 215 - 225 (2016)
Eleven antioxidants including nine phenolic compounds (rutin, quercetin, hesperidin, hesperetin, naringin, naringenin, chlorogenic acid, caffeic acid, ferulic acid), vitamin E (α-tocopherol), and butylated hydroxytoluene (BHT) were selected to investigate their inhibitory effects on thermal oxidation of cholesterol in air and lard. The results indicated that the unoxidized cholesterol decreased with heating time whilst cholesterol oxidation products (COPs) increased with heating time. The major COPs produced were 7α-hydroxycholesterol, 7β-hydroxycholesterol, 5,6β-epoxycholesterol, 5,6α-epoxycholesterol, and 7-ketocholesterol. When cholesterol was heated in air for an hour, rutin, quercetin, chlorogenic acid, and caffeic acid showed a strong inhibitory effect. When cholesterol was heated in lard, caffeic acid, quercetin, and chlorogenic acid demonstrated inhibitory action during the initial 0.5 h (p a high flame is recommended. If baking or deep fat frying food in oil, it is best to limit cooking time to within 0.5 h.
Atypical regioselective biohydrolysis on steroidal oxiranes by Aspergillus niger whole cells: Some stereochemical features
Bisogno, Fabricio R.,Orden, Alejandro A.,Pranzoni, Celeste Aguirre,Cifuente, Diego A.,Giordano, Oscar S.,Kurina Sanz, Marcela
, p. 643 - 652 (2007)
5,6-Epoxycholestan-3β-ol derivatives were hydrolyzed in a diastereoconvergent manner by growing and resting cells of several strains of Aspergillus niger, particularly A. niger ATCC 11394. These strains displayed opposite regioselectivity toward each isomer in an α and β epoxide mixture, thus, the nucleophilic attack took place at the less substituted and the most substituted carbon atom on each diasteromer, respectively. These biocatalysts opened trisubstituted oxiranes but were unable to hydrolyze the disubstituted oxiranes in the tested sterol derivatives. These findings suggest that A. niger strains possess another hydrolytic ability different from the commercial A. niger epoxide hydrolase (EH) that did not accept this kind of steroidal oxiranes as substrates.
A VERSATILE METHOD FOR PREPARATION OF O-ALKYLPEROXICARBONIC ACIDS: EPOXIDATION WITH ALKYLOXYCARBONYLIMIDAZOLES AND HYDROGEN PEROXIDE
Tsunokawa, Youko,Iwasaki, Shigeo,Okuda, Shigenobu
, p. 2113 - 2116 (1982)
A variety of O-alkylperoxycarbonic acids (2) were conveniently prepared in situ by utilizing alkyloxycarbonylimidazoles (1) as their precursors.Epoxidation of alkenes with such peroxy-acids was studied and their reactivities were compared with those of peroxycarboxylic acids.
