Saponin and sapogenol. XV. Antifungal glycosides from the sea cucumber Stichopus japonicus Selenka. (2). Structures of holotoxin A and holotoxin B.

Abstract

The structure of holotoxin A, the major antifungal glycoside isolated from the Far Eastern sea cucumber S. japonicus Selenka, elucidated on the bases of chemical and physicochemical evidence and enzymatic hydrolysis. Holotoxin B, a minor antifungal glycoside of the same origin, was suggested to be the glucoside of holotoxin A on the similar basis. Holotoxin C, another minor glycoside, was suggested to the similar type of glycoside as holotoxin A and B. Holotoxin A and B are distinctive by the possession of 2 .alpha.-linkages of D-xylose and D-quinovose in the oligosaccharide portion. Comparison of the anti-microbial activity of holotoxins with the various kinds of saponins isolated from the plant materials was presented.