Research

Marine Natural Products. Potent bioactive compounds are isolated from marine microbes that are found in ocean sediment samples as well as those that are associated marine invertebrates such as sponges, soft corals and tunicates. The pure microbial isolates are identified via molecular taxonomy and those which display good antimicrobial and/or antitumor activities are grown in large scale liquid fermentations. The fermentations are extracted and concentrated to yield crude extracts. These extracts are purified on silica gel and HPLC to afford pure compounds. The characterization of these compounds (including relative and absolute stereochemistries) is accomplished through one- and two- dimensional NMR as well as other spectroscopic and chemical means. Where possible, the semi-synthesis and optimization of lead bioactive compounds are conducted by chemical and biochemical means.

Biocatalysis. Analogs of potent bioactive compounds are generated by the microbial bioconversion of their parent congeners via a variety of fungi. Presently, new analogs of the of the chemopreventative agent curcumin and the anticancer compound formestane by the microorganisms Rhizopus oryzae and Beauveria bassiana respectively were isolated.

Citrus Research. Current work includes the isolation of bioactive toxins from saprophytic fungi that has shown to reduce the incidence of the citrus diseases Alternaria brown spot and melanose.