98 中国産ウリ科生薬土貝母より得られる新サイクリックビスデスモサイドについて : 構造と溶解促進効果  [in Japanese] 98 A NEW CYCLIC BISDESMOSIDE ISOLATED FROM CHINESE CUCURBITACEOUS MEDICINAL PLANTS "TU BEI MU" : STRUCTURE AND SOLUBILIZING EFFECT  [in Japanese]

An oleanane type triterpenoid glycoside, named Tubeimoside I (1) was isolated from rhizome of Bolbostemma paniculatum (Maxim.) Franquet. (Cucurbitaceae), a Chinese folk medicine, "Tu Bei Mu". The structure of 1 was revealed on the basis of the spectral and chemical evidences as shown in Scheme 1. The name, cyclic bisdesmoside is proposed for the glycoside of this type. It has been reported that the water solubility of the monodesmoside, saponin A from Sapindus mukurossi Gaertn. which causes remakable enhancement of the absorbtion of antibiotics from rat intestine and rectum, is greatly increased by the co-occurring bisdesmosides, mukurozi-saponin X,Y_1 and Y_2. It was observed that the solubilizing effect of the cyclic bisdesmoside 1 on saponin A as well as water insoluble Yellow OB was much more intense than the above mukurozi-saponins and the deacylated bisdesmoside (3). Studies on the chirality of 3-hydroxy-3-methyl-glutaric acid moiety of 1 and the other surfactive properties are under progress.