Starfish saponins, Part 51. Steroidal oligoglycosides from the starfish Distolasterias nipon.

Abstract

A reinvestigation of the extracts from the starfish Distolasterias nipon, collected at Mutsu Bay, Japan, has led to the isolation of six glycosides 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 Pycnopodia helianthoides and Pisaster ochraceus (family Asteridae), respectively. Two asterosaponins have been identified as the common versicoside A [7] and thornasteroside A [7a]. The two remaining glycosides of polyhydroxysteroids, named distolasterosides D4 [3] and D5 [4], and four asterosaponins designated nipoglycosides A [8], B [9], C [10], and D [11] are new compounds, and their structures have been elucidated mainly by interpretation of spectral data and comparison with known compounds.