Malabaricane triterpenes from a Great Barrier Reef collection of the sponge Jaspis stellifera

Abstract

Four new malabaricane triterpenes, related to malabaricane triterpenes obtained from a Fijian collection of the sponge Jaspis stellifera, have been isolated from a Great Barrier Reef collection of J. stellifera. The compounds have been identified, by a combination of spectral evidence and chemical degradations, as (13Z,15E,17E,22E)-3β-hydroxy-12-oxomalabarica-l3,15,17,22,24-pentaen- 28-oic acid (4), (13Z,15E,17E,22E)-3β-acetoxy-12-oxomalabarica-l3,15,17,22,24-pentaen-28-oic acid (5), (13Z,15E,17E)-3β,28-diacetoxy-22-hydroxymalabarica-13,15,17,24-tetraen-12-one (6) and (13Z)-15E,17E,22E)-3β-hydroxymalabarica-l3,15,17,22,24-pentaen-12-one (7).