Scopularides A and B, two new cyclodepsipeptides from the marine sponge-derived fungus Scopulariopsis brevicaulis

The Kieler Wirkstoffzentrum KiWiZ is devoted to the isolation and characterization of biologically active natural products from marine-derived microorganisms. We report here on products from the fungus Scopulariopsis brevicaulis isolated from the marine sponge Tethya aurantium . Despite the widespread distribution of Scopulariopsis spp., only one pyranol derivative and some methylarsines and -stibines were known so far from this genus. Our analyses revealed the presence of two novel cyclodepsipeptides, scopularides A ( 1 ) and B ( 2 ), which were isolated from a mycelium extract of the fungus by preparative HPLC as white microcrystalline powders along with the known tremorgenic alkaloid paxilline. The structures of the scopularides A and B were elucidated by NMR, MS, and chemical derivatization methods as cyclo (3-hydroxy-4-methyldecanoyl–Gly–l-Val– d-Leu– l-Ala–l-Phe) and cyclo (3-hydroxy-4-methyloctanoyl–Gly–l-Val–d-Leu–l-Ala–l-Phe) for scopularide A ( 1 ) and B ( 2 ), respectively. 1 References: 1. Yu, Z., et al. (2008) J. Nat. Prod., in press.