Marine cyanobacteria are prolific sources of bioactive secondary metabolites with
intriguing structures and, consequently, have tremendous potential to yield small
molecule therapeutic agents and biological probes. A collection of the cyanobacterium
Lyngbya confervoides from Ft. Lauderdale (Florida, USA) afforded four new serine protease inhibitors (1–4), consisting of multiple modified amino acid moieties [1–3], along with a cyclic
pentapeptide having a rare ureido linkage (5) [3]. The planar structures of (1–5) were determined by extensive spectroscopic analysis and the absolute configurations
established using advanced Marfey's method and chiral HPLC analysis of chemical degradation
products.
Acknowledgements: Florida Sea Grant College Program for financial support; AMRIS (McKnight
Brain Institute, University of Florida) and NHMFL External User Program (NSF) for
NMR infrastructure and instrument time.
References: 1. Matthew, S. et al. (2007)J. Nat. Prod. 70:124.
2. Taori, K. et al. (2007)J. Nat. Prod. 70:1593.
3. Matthew, S. et al. (2008) http://www.sciencedirect.com/science? _ob=RedirectURL&_method=gejLink&_linkType=general&_cdi=5289&_issn=00404020&_targetURL
=http%3A%2F%2Fwww.elsevier.com%2Flocate%2Fissn%2F00404020&_acct=C000050221&_version=1&_userid=10&md5=4ccaf6fc027b281239b16e0bb366e62bTetrahedron
64:4081.