80 昆虫におけるシトステロール側鎖切断反応の中間体フコステロールエポキシドについて

概要

論文の詳細を見る
Previously we reported that fucosterol epoxide(3) is a key intermediate in the conversion of sitosterol(1) into cholesterol (5) in silkworm, Bombyx mori. A detailed study on this dealkylation mechanism, especially on which of the stereoisomers, 24R, 28R(3b) or 24S, 28S(3a) of fucosterol epoxide is the actual intermediate has been undertaken. [24R, 28R]- and [24S,28S]-fucosterol epoxides were chemically synthesized and their configurations were unequivocally determined by interrelation with sitosterol and clionasterol. The cell free systems which convert fucosterol to fucosterol epoxide and also the epoxide to desmosterol and cholesterol were developed. The data obtained by the incubations with the cell free system as well as in vivo experiments show that the stereospecificity both in the formation of the epoxide from fucosterol and its conversion to desmosterol is not so rigid. It may be considered that the dealkylation reaction would proceed via both 24R,28R(3b)- and 24S,28S(3a)-epoxides as an intermediate.
天然有機化合物討論会の論文
1978-08-22