Diverse metabolites of coral reef organisms*
Junichi Tanaka, Masayuki Kuniyoshi, Chiaki Tanaka, Hamad H. Issa, Walter Balansa, Masahito Otsuka, Wahome P. Githige, and Tatsuo Higa‡
Department of Chemistry, Biology, and Marine Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
Abstract: A detailed mechanism for the spontaneous transformation of 2-chloro-1-hydroxyoctoda-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.
*Paper based on a presentation at the 24th International Symposium on the Chemistry of Natural Products and the 4th International Congress on Biodiversity, held jointly in Delhi, India, 26-31 January 2004. Other presentations are published in this issue, pp. 1-344.