Ulososide B, a new unusual norlanostane-triterpene glycoside and its genuine aglycone from the Madagascar sponge Ulosa sp.

Abstract A new triterpene glycoside, ulososide B (1) , was isolated from the sponge Ulosa sp and its structure was elucidated on the basis of spectroscopic data and obtaining of genuine aglycone ( 2 ) after acid hydrolysis.