Marine natural products possessing guanidine functionalities display a considerable array of biological activity and not surprisingly have attracted considerable synthetic interest. This review discusses the isolation of several guanidine containing metabolites, primarily from the sponge Ptilocaulis spiculifer, but also from other marine organisms. It also explores the synthetic methodologies adopted for their preparation and speculates on the structural similarity of the metabolite ptilomycalin A to abiotic guanidine based anionic receptor molecules.
Isolation of ptilomycalin A and related metabolitesNaturally occurring and synthetic compounds containing guanidine are of considerable interest due both to the hydrogen-bond mediated interaction of guanidinium ions and because of the wide range of biological activities these substances display. 1 Recent interest in marine natural products has seen a steady increase in the number of metabolites isolated from these sources and a metabolite of particular interest isolated from the sponge Ptilocaulis spiculifer 2 in 1989 is ptilomycalin A 1. This alkaloid has a unique and fascinating structure consisting of a pentacyclic guanidinium core linked to a spermidine unit via a w-hydroxy acid spacer group. The same compound was also isolated from a Red Sea sponge of the genus Hemimycale sp. 3 and subsequently from the sponge Batzella sp. 4 and the starfishes Fromia monilis and Celerina heffernani 5 (Scheme 1).Ptilomycalin A displays a remarkable range of biological activities including cytotoxicity against the following cell lines; P388 (IC 50 0.1 mg mL 21 ), L1210 (IC 50 0.4 mg mL 21 ), and KB (IC 50 1.3 mg mL 21 ) in addition to antifungal activity against Candida albicans (MIC 0.8 mg mL 21 ) as well as very good antiviral activity (HSV) at a concentration of 0.2 mg mL 21 . 2 Previous to the isolation of ptilomycalin A the related guanidinium alkaloids ptilocaulin 2 and isoptilocaulin 3 had been isolated from the same sponge in 1981 6 (Scheme 2).
Laura Heys graduated (MChem) from Bangor University in1999, she is currently pursuing a career in the chemical industry. Christopher G. Moore graduated (BSc Hons) from Bangor in 1995 and is currently finishing his postgraduate studies which have focused on the total synthesis of guanidine containing marine metabolites. Patrick J. Murphy graduated (Since gaining this post he has concentrated his research efforts on the development of new methodology and its applications in synthesis, with two key themes being the synthesis of naturally occurring guanidine containing marine alkaloids and new applications of Wittig chemistry.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.