Biologically active compounds isolated from marine sources have had increasing interest in recent years with significant research going into the discovery and isolation of novel marine polysulfide natural products. Varacin, probably the most widely studied marine polysulfide to date was the subject of much debated structure elucidation attempts, and more recently several successful synthetic approaches have been published. The work published aims to increase our understanding of marine polysulfide compounds existence in nature and determine the origins of their biological activity. (+)-Aplidium trisulfide which was isolated from Aplidium Sp. D in 1989 by Munro et al has been shown to exhibit in vitro antimicrobial, antileukemic and cytotoxic properties. These intriguing biological effects have led our work towards developing a novel synthetic route toward aplidium trisulfide by both chiral and racemic routes. Aplidium trisulfide is of special significance as it is very rare to isolate enantiomeric compounds from marine sources. Two other closely related marine alkaloids fasmerianamine A and B are also of synthetic interest to us due to their close resemblance to the structure of aplidium trisulfide. The fasmerianamines were isolated by Copp et al from the marine ascidian Hypsistozoa fasmeriana in 2001.
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.