Investigation of the polar steroids from an Antarctic starfish of the family Echinasteridae: Isolation of twenty seven polyhydroxysteroids and steroidal oligoglycosides, structures and biological activities

An investigation of the extracts from a starfish collected in the Antarctic Sea, Echinasteridae family, has led to the isolation of thirteen glycosides of polyhydroxysteroids (1-13), fourteen polyhydroxysteroids (14-27), which are the subject of this report, and seven asterosaponins (penta-and hexa-saccharides), described in a previous paper. Glycosides 1-13 are composed of the same 3 beta,4 beta,6 alpha,8,15 beta,26-hexahydroxysteroidal aglycone with small variations in the side chains, and a carbohydrate portion made up of one or two monosaccharide units attached at C-26, except 11, which has a steroidal aglycone with a 24,28-dihydroxylated side chain and the monosaccharide unit attached at C-24. The structures of the polyhydroxysteroids (14-27) have the hydroxyl groups typically disposed on one side of the steroid nucleus, i.e. 3 beta,4 beta,6 beta (or alpha),8,15 alpha (or beta) and 16 beta and the majority of them possess a 26-hydroxyl function. A selection of fifteen compounds were tested against human non-small-cell lung carcinoma cells and found to be moderately cytotoxic. Copyright (C) 1996 Elsevier Science Ltd