50681-37-3Relevant academic research and scientific papers
Synthesis of potential C27-intermediates in bile acid biosynthesis and their deuterium-labeled analogs
Shoda, Junichi,Axelson, Magnus,Sjoevall, Jan
, p. 119 - 125 (2007/10/02)
In connection with studies of alternative pathways in bile acid biosynthesis, potential intermediates in a pathway starting with 27-hydroxylation of cholesterol have been prepared in natural and deuterated forms. Established methods were used to prepare 27-hydroxycholesterol and 3β-hydroxy-5-cholestenoic acid. Clemmensen reduction of kryptogenin in unlabeled and deuterated solvents yielded 27-hydroxycholesterol and 16-oxo-5-cholestene-3β,27-diol, which were separated by adsorption chromatography on Unisil. The labeled 27-hydroxycholesterol and 3β-hydroxy-5-cholestenoic acid derived from it consisted of molecules with seven (50%), six (20%), and eight (20%) deuterium atoms, and unlabeled molecules were not detected. The acetates of 27-hydroxycholesterol and methyl 3β-hydroxy-5-cholestenoate were 7α-hydroxylated in a copper-catalyzed reaction with ert-butylperbenzoate, and the products were purified by chromatography on Unisil. The 7β-epimers were obtained as side products. Labeled 3β, 7α-dihydroxy-5-cholenic acid was prepared in the same way from 3β-hydroxy-5-[2,2,4,4,23-2H5]-cholenoic acid. The 3-oxo-Δ4 analogs of the 3β-hydroxy-Δ5 compounds were prepared by oxidation with cholesterol oxidase. The labeled products had the same isotopic composition as the starting materials. Gas chromatographic retention indices and mass spectral characteristics of the trimethylsilyl ether derivatives of the neutral steroids and the methylated acids are given for all compounds. (Steroids 58:119-125, 1993).
Biosynthetic studies of marine lipids. 39.1 19-norsterols: The course of c-19 methyl elimination
Rabinowitz, Michael H.,Djerassi, Carl
, p. 304 - 317 (2007/10/02)
The biosynthesis of 19-norstanols in the Mediterranean sponge, Axinella polypoides, was investigated through the use of radiotracer experiments. It was found that the conversion of cholesterol (7) to 19-nor-5α-chotestan-3β-ol (8) involved oxidation at C-3 with the distribution of the abstracted hydride from the 3α-position of dietary cholesterol into all of the 19-norstanols of the native mixture. Furthermore, while the efficiency of conversion of Δ5-19-oxygenated sterol precursors 19-hydroxycholesterol (9) and 3β-hydroxycholest-5-en-19-oic acid (10) to 8 was low, the efficiency of the conversion of 19-hydroxycholest-4-en-3-one (23) to 8 was high, suggesting that the principal pathway for 19-norstanol biosynthesis involves oxidative isomerization of a dietary Δ5-3β-hydroxy sterol to the δ4-3-ketone before oxidation at C-19. It was also shown that the conversion of cholesterol to 19-nor-5α-cholestan-3β-ol involves the stereospecific loss of the 4β-hydrogen atom. It was further determined that the biological demethylation pathway is suppressed for dietary sterols bearing an unconventional configuration at C-20 in the hydrocarbon side chain.
On the C-25 Chirality of 26-Hydroxycholesterol
Byon, Chang-Yon,Gut, Marcel,Toome, Voldemar
, p. 3901 - 3903 (2007/10/02)
The stereospecific synthesis of (25S)-26-hydroxycholesterol with a chiral synthon derived from (S)-(+)-3-hydroxy-2-methylpropanoic acid is described and the Cotton effects of the CD spectra were found not to be a general means for distinguishing epimers of monohydric secondary alcohols or for distinguishing epimers in which the chiral center is in the α position to the primary alcoholic function.
