Diverse metabolites of coral reef organisms

A detailed mechanism for the spontaneous transformation of 2-chloro-1-hydroxy-octoda-3(8),5-dien-4-one, a metabolite of Portieria hornemanni, into 4,5-dimethylbenzo[b]-furan was presented. Five new terpenoids have been isolated from the red alga Laurencia luzonensis. Five species of sponges yielded various metabolites: furanosesterterpenes from Ircinia sp., scalarane derivatives from Phyllospongia sp., polyketides from Theonella cf. swinhoei, a polyacetylene from Callyspongia sp., and cyclic depsipeptides from Suberites japonicus. Other new metabolites were sponge-derived secomanoalide derivative and imidazole alkaloids from nudibranchs, briarane class diterpenes from octocorals, and cyclofarnesylated hydroquinones, floresolides A-C, from an ascidian, Aplidium sp. Many of these compounds showed cytotoxicity.