BIOACTIVE NATURAL-PRODUCTS FROM BLUE-GREEN-ALGAE

Since 1981 we have cultured and prepared lipophilic and hydrophilic ex tracts from more than 1500 strains representing some 400 species of bl ue-green algae. Screening for a wide variety of potentially useful bio activities, including cytotoxic, multi-drug-resistance reversal, antif ungal, and antiviral effects, has led to the discovery and identificat ion of numerous novel bioactive metabolites including peptides, macrol ides and glycosides. A systematic evaluation of the chemical and envir onmental factors that influence the production of secondary metabolite s in Scytonema ocellatum, which produces tolytoxin (a macrocyclic lact one that depolymerizes actin in vivo to disrupt cell division in eukar yotic organisms), has shown that cyanophytes can be manipulated in cul ture to improve growth and product yields.