Bioactive metabolites from marine algae: Recent results

The recent literature (1992 - early 1996) on secondary metabolites from marine algae has been reviewed and selected results concerning more than one hundred bioactive compounds are reported. The review is specifically devoted to the seaweeds (Chlorophyta, Phaeophyta and Rhodophyta) and does not include metabolites from microalgae and Cyanobacteria (blue-green algae). Emphasis has been placed on novel compounds, but some recent reports about previously known bioactive metabolites have also been reviewed. A variety of bioactive metabolites has recently been obtained from marine algae, including terpenoids (among them the halogenated mono-and sesquiterpenoids typically produced by red algae), compounds of mixed biogenesis and further miscellaneous compounds. The reported activities range from properties of pharmacological interest, i.e. cytotoxicity against tumoral cultured cells, antimicrobial activity, antiviral activity, etc., to other activities of ecological or agronomical significance, such as antifeedant activity against marine predators or insecticidal activity. The review of the recent literature on secondary metabolites from marine algae indicates that the search for new bioactive metabolites from seaweeds is an active sector of the chemistry of natural products, stimulating the application of sophisticated physical techniques like two-dimensional NMR as well as intriguing syntheses of compounds of biomedical interest.