33 インドネシア薬用植物Merremia mammosa塊根中の樹脂配糖体Merremoside類の化学構造(口頭発表の部)

"Bidara upas", the tuber of Merremia mammosa CHOIS (Convolvulaceae), is an Indonesian folk medicine which is said to be useful for treating diabetes and affection of the throat and respiratory system. As a part of our investigations of Indonesian medicinal plants, we have examined the chemical constituents of the tuber. We have isolated nine new resin-glycosides named merremosides a, b, c, d, e, f, g, h_1, and h_2, among which the structures of a, b, c, d, f, and g were reported previously where the 11R configuration of jalapinolic acid, the common aglycone of merremosides, was based on the application of Horeau's method. In order to confirm the absolute configuration of jalapinolic acid, we have synthesized jalapinolic acid (16), the 11-epimer (18), and the oligoside (21a) by use of Sharpless epoxidation, and we have found that jalapinolic acid has in fact 11S configuration. Consequently, the structures of merremosides a (1), b (2), c (3), d (4), f (5), and g (6) have been formulated as shown. Furthermore, based on the chemical and physicochemical evidence, the structures of merremosides e (19), h_1 (27), and h_2 (28) have been determined. Merremosides are macrocyclic lactone oligosides. It has been found that merremoside a (1) exhibits ion-transport activity for K^+, Na^+, and Ca^<++>ions through artificial membrane, whereas all merremosides have been shown to transport Ca^<++> ion by the human erythrocyte method. Merremosides b (2) and d (4) have been found to exhibit anti-serotonic activity.