BIOACTIVE NATURAL-PRODUCTS FROM BLUE-GREEN-ALGAE

Since 1981 we have cultured and prepared lipophilic and hydrophilic extracts from more than 1500 strains representing some 400 species of blue-green algae. Screening for a wide variety of potentially useful bioactivities, including cytotoxic, multi-drug-resistance reversal, antifungal, and antiviral effects, has led to the discovery and identification of numerous novel bioactive metabolites including peptides, macrolides and glycosides. A systematic evaluation of the chemical and environmental factors that influence the production of secondary metabolites in Scytonema ocellatum, which produces tolytoxin (a macrocyclic lactone that depolymerizes actin in vivo to disrupt cell division in eukaryotic organisms), has shown that cyanophytes can be manipulated in culture to improve growth and product yields.