Structures of four new triterpenoidal oligoglycosides, bivittoside A,B,C, and D, from the sea cucumber Bohadschia bivittata Mitsukuri.

On the basis of chemical and physicochemical evidence, the structures of four triterpenoidal oligoglycosides, bivittoside A, B, C, and D from the sea cucumber Bohadschia bivittata MITSUKURI, have been elucidated as 6, 8, 9, and 10, respectively. A new homoannular dienic sapogenol was isolated as the acetate and the highly strained structure (4a) has been elucidated.