Isolation and structure of five lyngbyabellin derivatives from a Papua New Guinea collection of the marine cyanobacterium Lyngbya majuscula

Five new lyngbyabellin analogs along with a known compound, dolabellin, have been isolated from the marine cyanobacterium Lyngbya majuscula collected from Papua New Guinea. The structures of lyngbyabellins E-I were elucidated through extensive spectroscopic analysis, including HR-FABMS and I D and 2D NMR experiments. The absolute configurations of lyngbyabellin E and H were ascertained by chiral HPLC and GUMS analysis of degradation products, in combination with NMR experiments. All five lynabyabellins showed cytotoxicity to NCI-H460 human lung tumor and neuro-2a mouse neuroblastoma cell lines with LC50 values between 0.2 and 4.8 mu M. (c) 2005 Elsevier Ltd. All rights reserved.