18 Breynogeninの構造研究

概要

論文の詳細を見る
Breynins A (C_<40>H_<56>O_<23>S) and B (C_<40>H_<56>O_<24>S), which have been isolated from Breynia officianlis Hemsl (Family Euphorbiaceae), are new sulfur-containing glycosides with potent hypocholesterolemic activity. Acid hydrolysis of breynin A (I) in methanolic hydrochloric acid afforded glucose, rhamnose, p-hydroxy-benzoic acid and the aglycone, breynogenin (II, C_<22>H_<26>O_9S), along with its secondary degradation products, breynolide (III, C_<15>H_<22>O_7S) and isobreynogenin (IV, C_<22>H_<26>O_9S). The structure of II was determined to be a p-hydroxy-benzoyl ester of III, the site of esterification being the C-11 axial hydroxyl group of III (Fig. 2). It is most probable that IV is a conformational isomer of II with the tetrahydropyranyl ring of II being inverted in IV, since IV has an axial methyl at C-12 and an equatrial ester group at C-11 (Fig. 3).
天然有機化合物討論会の論文
1975-10-01