"Among the various toxins isolated, the chlorosulfolipids are particularly intriguing because of their structural and stereochemical complexity. The mechanism of biological activity remains unknown. The lack of availability of the natural products has impaired more in-depth studies aimed at pharmacological, biological, and chemical characterization for proper evaluation of the risk for human health and their role in nature. The proposal takes as its basis this unusual class of natural products and delineates a multifaceted program of inquiry involving: (1) structural characterization of the most complex chlorosulfolipid isolated to date, (2) conformational studies in solution of chlorinated lipids, (3) synthesis and study of brominated lipid analogs, (4) development of analytical methods for detection of these toxins in the environment, (5) the discovery and development of reagents and catalysts for asymmetric chlorination of olefins, (6) examination of lipid conformation in constrained media, (7) examination of the mechanism of anchimeric assistance by chlorides, and (8) applications to drug discovery."