Dysideaprolines A-F and barbaleucamides A-B, novel polychlorinated compounds from a Dysidea species

Chemical investigation of a marine sponge, Dysidea sp., collected at Bararin Island, Philippines, has afforded the novel metabolites 1-6, proline-derived analogues of dysidenin (7). We have termed compounds 1-6 dysideaprolines A-F, respectively. Also isolated were compounds 8 and 9, structural analogues of barbamide (10), a metabolite originally isolated from the cyanobacterium Lyngbya majuscula. We have termed these novel compounds barbaleucamides A (8) and B (9). It is most probable that the compounds presented here are actually derived from a symbiotic cyanobacterium found in close association with the Dysidea sp. Structure elucidation of the isolated metabolites involved high-field 2D NMR spectroscopy including H-1-H-1 COSY, HSQC, and HMBC.