Starfish saponins. Part 40. Structures of two new ‘asterosaponins’ from the starfish Patiria miniata: patirioside A and patirioside B
Abstract
An investigation of the extracts from the starfish Patiria miniata has led to the isolation of four ‘astero-saponins.’ Two are new compounds designated as patirioside A (1) and patirioside B (2). They are hexaglycosides with two branches and have been characterized as sodium (20R,22R,23S,24S)-6α-O-{α-L-arabinopyranosyl-(1→2)-[(β-D-fucopyranosyl-(1→4)]-β-D-glucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-β-D-quinovopyranosyl}-22,23-epoxy-20-hydroxy-24-methyl-5α-cholest-9(11)-en-3β-yl sulphate (1) and sodium (20S)-6α-O-{β-D-fucopy-ranosyl-(1→2)-[β-D-galactopyranosyl-(1→4)]-β-D-glucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-quinovopyranosyl-(1→3)-β-D-quinovopyranosyl}-20-hydroxy-23-oxo-5α-cholest-9(11 )-en-3β-yl sulphate (2). The spectral data of the two remaining asterosaponins agree with those of pectinioside G (3), an hexaglycoside recently described from Asterina pectinifera, and with those of acanthaglycoside C (4), a pentaglycoside first isolated from Acanthaster planci.