Mitsoamide: A cytotoxic linear lipopeptide from the Madagascar marine cyanobacterium Geitlerinema sp.*
Eric H. Andrianasolo1, Douglas Goeger1, and William H. Gerwick1,2
1College of Pharmacy, Oregon State University, Corvallis, OR 97331, USA; 2Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92037, USA
Abstract: A new cytotoxic and linear peptide (IC50 460 nM to NCI-H460 human lung tumor cells) was isolated from the marine cyanobacterium Geitlerinema sp. The planar structure of mitsoamide was deduced by 1D and 2D NMR experiments in combination with MS analyses. The structure of mitsoamide contains an unusual polyketide unit (3,7-dimethoxy-5-methyl-nonanedioic acid, DMNA), incorporates a homolysine (HomoLys) residue and possesses a highly unusual piperidine aminal moiety. The configurations of the relatively common amino acids present in mitsoamide (Ala, Ile, N-Me-Ile, Phe, Val) were determined by chiral HPLC analysis of the acid hydrolysate.
Keywords: cyanobacteria; cytotoxins; lipopeptides; polyketides; marine.
*Pure Appl. Chem. 79, 467-823 (2007) pp. 467-823. An issue of reviews and research papers based on lectures presented at the 25th International Symposium on Chemistry of Natural Products (ISCNP-25) and 5th International Conference on Biodiversity (ICOB-5), held jointly in Kyoto, Japan, 23-28 July 2006, on the theme of natural products.