STARFISH SAPONINS .51. STEROIDAL OLIGOGLYCOSIDES FROM THE STARFISH DISTOLASTERIAS-NIPON

A reinvestigation of the extracts from the starfish Distolasterias nip on, collected at Mutsu Bay, Japan, has led to the isolation of six gly cosides of polyhydroxysteroids and six asterosaponins. Four steroidal glycosides have been identified as distolasterosides D1 [1] and D2 [2] (previously isolated from the same organism), and pycnopodioside C [5 ] and pisasteroside A [6], previously found in the related species Pyc nopodia helianthoides and Pisaster ochraceus (family Asteridae), respe ctively. Two asterosaponins have been identified as the common versico side A M and thornasteroside A [7a]. The two remaining glycosides of p olyhydroxysteroids, named distolasterosides D4 [3] and D, [4], and fou r asterosaponins designated nipoglycosides A [8], B [9], C [10], and D [11] are new compounds, and their structures have been elucidated mai nly by interpretation of spectral data and comparison with known compo unds.