1250-95-9Relevant academic research and scientific papers
Stereoselective glycoconjugation of steroids with selenocarbohydrates
Affeldt, Ricardo F.,Santos, Francisco P.,Da Silva, Rafael S.,Rodrigues, Oscar E. D.,Wessjohann, Ludger A.,Lüdtke, Diogo S.
, p. 93905 - 93914 (2016)
A methodology that brings together sugar and steroid scaffolds linked by a selenium atom is discussed in this work. A series of 6β and 3α glycoconjugated steroids were achieved by stereoselective nucleophilic substitution of cholesterol, pregnenolone, stigmasterol and sitosterol with different seleno-pyranosides and furanosides.
Synthesis and catalytic activity of Ti-MCM-41 nanoparticles with highly active titanium sites
Lin, Kaifeng,Pescarmona, Paolo P.,Vandepitte, Hans,Liang, Duoduo,Van Tendeloo, Gustaaf,Jacobs, Pierre A.
, p. 64 - 70 (2008)
Ti-MCM-41 nanoparticles 80-160 nm in diameter (Ti-MCM-41 NP) were successfully prepared by a dilute solution route in sodium hydroxide medium at ambient temperature. Ti-MCM-41 NP were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, SEM, TEM, FT-IR, and UV-vis spectroscopy. The characterization results showed the existence of highly ordered hexagonal mesoporous structure and tetrahedral Ti species in Ti-MCM-41 NP. In the epoxidation of cyclohexene with aqueous H2O2, Ti-MCM-41 NP displayed higher conversion and initial reaction rate than a Ti-MCM-41 sample with normal particle size (Ti-MCM-41 LP). Diffusion of the reactants was accelerated and the accessibility to the catalytic Ti species was enhanced in the shorter channels in Ti-MCM-41 NP samples. Ti-MCM-41 NP showed much higher selectivity for cyclohexene oxide compared with Ti-MCM-41 LP, suggesting reduced hydrolysis of cyclohexene oxide with water in the former case. The increased selectivity for cyclohexene oxide can be attributed to the lower concentration of residual surface silanols in Ti-MCM-41 NP and the shorter residence time of epoxide in the shorter mesoporous channels. Ti-MCM-41 NP also appears to be a suitable catalyst in the epoxidation of a bulky substrate, like cholesterol, with tert-butyl hydroperoxide.
Epoxidation and reduction of cholesterol, 1,4,6-cholestatrien-3-one and 4,6-cholestadien-3β-ol
Ma, Eunsook,Kim, Haksoon,Kim, Eunjeong
, p. 245 - 250 (2005)
Many naturally occurring polyhydroxylated sterols and oxysterols exhibit potent biologic activities. This paper describes reagent and position selectivity of epoxidation and reduction of cholesterol derivatives. Cholesterol was reacted with m-chloroperoxybenzoic acid (m-CPBA) to form 5α,6α-epoxycholestan-3β-ol, but in reaction with 30% H 2O2, it did not reacted. 1,4,6-Cholestatrien-3-one was obtained from cholesterol and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. 1,4,6-Cholestatrien-3-one was reacted with 30% H2O 2 and 5% NaOH in methanol to give 1α,2α-epoxy-4,6- cholestadien-3-one, which was stereoselectively reduced with NaBH4 to form 1α,2α-epoxy-4,6-cholestadien-3β-ol and reduced with Li metal in absolute ethanol to give 2-ethoxy-1,4,6-cholestatrien-3-one. And 1,4,6-cholestatrien-3-one was epoxidized with m-CPBA in dichloromethane to afford 6α,7α-epoxy-1,4-cholestadien-3-one, which was reacted with NaBH4 to synthesize 6α-hydroxy-4-cholesten-3-one and reduced Li metal in absolute ethanol to form 2-ethoxy-1,4,6-cholestatrien-3-one, respectively. 1,4,6-Cholestatrien-3-one was reduced with NaBH4 in absolute ethanol to form 4,6-cholestadien-3β-ol, which was reacted with 30% H2O2 to leave original compound, but was reacted with m-CPBA to give 4β,5β-epoxy-6-cholesten-3β-ol as the major product and 4β,5β-epoxy-6α,7α-epoxycholestan-3β-ol as the minor product.
A series of multi-hydroxy sterol anti-tumor medicine and its synthesis method and application (by machine translation)
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Paragraph 0034-0038; 0049-0052; 0063-0066; 0077-0080, (2019/06/27)
The present invention discloses a series of multi-hydroxy sterol anti-tumor medicine and its synthesis method and application, the series of the general formula (I) drug structure shown, and its cell toxicity test, aimed at improving the potency and selectivity. The series of multi-hydroxy sterol anti-tumor drugs to the three kinds of cancer cell (Hela, A549, MCF - 7) and a kind of organic selenium cell line (RWPE - 1) detected. The results show that, the series of multi-hydroxy sterol as anti-tumor drug has strong potency, can effectively inhibit the proliferation of the cancer cell line of three kinds, but also to the normal human cells of low toxicity. (by machine translation)
H-Atom Abstraction vs Addition: Accounting for the Diverse Product Distribution in the Autoxidation of Cholesterol and Its Esters
Zielinski, Zosia A. M.,Pratt, Derek A.
, p. 3037 - 3051 (2019/02/19)
We recently communicated that the free-radical-mediated oxidation (autoxidation) of cholesterol yields a more complex mixture of hydroperoxide products than previously appreciated. In addition to the epimers of the major product, cholesterol 7-hydroperoxide, the epimers of each of the regioisomeric 4- and 6-hydroperoxides are formed as is the 5α-hydroperoxide in the presence of a good H-atom donor. Herein, we complete the story by reporting the products resulting from competing peroxyl radical addition to cholesterol, the stereoisomeric cholesterol-5,6-epoxides, which account for 12% of the oxidation products, as well as electrophilic dehydration products of the cholesterol hydroperoxides, 4-, 6-, and 7-ketocholesterol. Moreover, we interrogate how their distribution - and abundance relative to the H-atom abstraction products - changes in the presence of good H-atom donors, which has serious implications for how these oxysterols are used as biomarkers. The resolution and quantification of all autoxidation products by LC-MS/MS was greatly enabled by the synthesis of a new isotopically labeled cholesterol standard and corresponding selected autoxidation products. The autoxidation of cholesteryl acetate was also investigated as a model for the cholesterol esters which abound in vivo. Although esterification of cholesterol imparts measurable stereoelectronic effects, most importantly reflected in the fact that it autoxidizes at 4 times the rate of unesterified cholesterol, the product distribution is largely similar to that of cholesterol. Deuteration of the allylic positions in cholesterol suppresses autoxidation by H-atom transfer (HAT) in favor of addition, such that the epoxides are the major products. The corresponding kinetic isotope effect (kH/kD ~ 20) indicates that tunneling underlies the preference for the HAT pathway.
Ring opening of epoxides with [18F]FeF species to produce [18F]fluorohydrin PET imaging agents
Verhoog, Stefan,Brooks, Allen F.,Winton, Wade P.,Viglianti, Benjamin L.,Sanford, Melanie S.,Scott, Peter J.H.
supporting information, p. 6361 - 6364 (2019/06/07)
A simple technique for the preparation of [18F]HF has been developed and applied to the generation of an [18F]FeF species for opening sterically hindered epoxides. This method has been successfully employed to prepare four drug-like molecules, including 5-[18F]fluoro-6-hydroxy-cholesterol, a potential adrenal/endocrine PET imaging agent. This easily automated one-pot procedure produces sterically hindered fluorohydrin PET imaging agents in good yields and high molar activities.
Chemoselective epoxidation of cholesterol derivatives on a surface-designed molecularly imprinted Ru-porphyrin catalyst
Muratsugu, Satoshi,Baba, Hiroshi,Tanimoto, Tatsuya,Sawaguchi, Kana,Ikemoto, Satoru,Tasaki, Masahiro,Terao, Yosuke,Tada, Mizuki
supporting information, p. 5114 - 5117 (2018/05/26)
A new molecularly imprinted Ru-porphyrin complex catalyst on a SiO2 support was designed, prepared, and characterized in a step-by-step manner for the C5C6 epoxidation of cholesterol derivatives. High chemoselectivity for the C5C6 epoxidation of cholesterol derivatives without protecting the 3-position OH group and other oxidizable functional groups was achieved on the molecularly imprinted catalyst.
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
supporting information, p. 92 - 100 (2017/09/19)
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.
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 (2016/02/03)
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.
Cholesterol transformations during heat treatment
Derewiaka,Molińska
, p. 233 - 240 (2015/01/09)
The aim of the study was to characterise products of cholesterol standard changes during thermal processing. Cholesterol was heated at 120 °C, 150 °C, 180 °C and 220 °C from 30 to 180 min. The highest losses of cholesterol content were found during thermal processing at 220 °C, whereas the highest content of cholesterol oxidation products was observed at temperature of 150 °C. The production of volatile compounds was stimulated by the increase of temperature. Treatment of cholesterol at higher temperatures i.e. 180 °C and 220 °C led to the formation of polymers and other products e.g. cholestadienes and fragmented cholesterol molecules. Further studies are required to identify the structure of cholesterol oligomers and to establish volatile compounds, which are markers of cholesterol transformations, mainly oxidation.
