This research will address several specific areas of secondary metabolite biosynthesis in blue-green algae. The first group of compounds to be investigated includes the potent anticholinesterase anatoxin-a(s) from Anabaena flos-aquae, the hepatotoxic cyclic peptides microcystin-LR from Microcytis aeruginosa and nodularin from Nodularia spumigena, the neurotoxic alkaloids anatoxin-a and homoanatoxin-a from Oscillatoria agardhii, and the inflammatory agents lyngbyatoxin A and debromoaplysiatoxin from Lyngbya majuscula. Studies also will be carried out on the isolation, structure determination and biosynthesis of new toxins from cyanophytes. The second major area will focus on a continuation of studies on the biosynthesis of hapalindole A, a fungicidal indole alkaloid from Hapalosiphon fontinalis, and tolytoxin, mirabilene A isonitrile, mirabimide E, and tantazole B, representatives of four classes of structurally unique and diverse natural products from Scytonema mirabile. Studies in a third area will involve the biosynthesis of cylindrocyclophane A from Cylindrospermum licheniforme, the first ?m,n!paracyclophane to be found in Nature, and an extracellular substance which stimulates sporulation in C. licheniforme. Finally studies will be carried out on the isolation, structure determination, and biosynthesis of other unusual natural products from blue-green algae, e.g. synechocin, an antiviral compound from the marine cyanophyte Synechococcus elongatus, and new alkaloids from cyanophytes belonging to the Stigonematales. %%% With this award the Synthetic Organic Program of the Chemistry Division will support the research of Dr. Richard E. Moore of the Department of Chemistry at the University of Hawaii, Manoa. The major goal of the research is to understand the biosynthesis of secondary metabolites in blue-green algae, especially freshwater, brackish-water, and marine cyanophytes which produce toxins implicated in wildlife, domestic animal, and human poisonings.
