52936-69-3Relevant academic research and scientific papers
Biosynthesis of 24β-alkyl-Δ25-sterols in hairy roots of Ajuga reptans var. atropurpurea
Yagi, Tomoko,Morisaki, Masuo,Kushiro, Tetsuo,Yoshida, Hiroko,Fujimoto, Yoshinori
, p. 1057 - 1064 (1996)
A hairy root culture of Ajuga reptans var. atropurpurea contains clerosterol, 22-dehydroclerosterol and cholesterol as its sterol constituents. Feeding of [26-, 27-13C2]desmosterol to this culture and 13C NMR analysis of the resulting biosynthesized sterols showed that the substrate was efficiently incorporated into clerosterol and codisterol. Feeding of [26-13C] and [27-13C]desmosterols revealed that the C-24 alkylation takes place in a highly specific manner wherein the 26- and 27-methyl groups of the substrate becomes C-26 (vinyl methyl) and C-27 (exomethylene carbon), respectively, of the two Δ25-sterols. Further, feeding of [24-2H]desmosterol and 2H NMR analysis of the products showed that H-24 of clerosterol and codisterol is derived from H-24 of desmosterol. Finally, [28-13C]ergosta-5,24(28)-dien-3β-ol was shown to be converted into clerosterol and 22-dehydroclerosterol, but not into codisterol. On the basis of these data, possible biosynthetic mechanism of 24β-alkyl-Δ25-sterols in this plant is proposed. Copyright
Structural and Stereochemical Aspects of Base-Catalyzed Double Bond Isomerization of Sterols with Unsaturated Side Chains
Li, Hui-ting,Djerassi, Carl
, p. 4298 - 4303 (2007/10/02)
A careful analysis of the N-lithioethylenediamine-catalyzed isomerization of 22-, 23-, and 24-methylenecholesterol demonstrated the existence of subtle factors which are responsible for the kinetically and thermodynamically preferred products.In general, the results can be related to the anticipated energy preferences of the intermediate carbanions.Through the use of 1H and 13C NMR spectroscopy the configuration of the various double bond isomers could be established.Since all major products are readily separated by HPLC, such base-catalyzed isomerization offers a convenient synthetic route to a variety of stereochemically pure sterol olefins, which either have been found in the marine environment or may be detected in the future.
