Professor Frank R. Stermitz, of the Department of Chemistry of Colorado State University, is supported by the Organic Synthesis Program for his studies of alkaloids of importance in plant-insect interactions. His studies focus on the isolation, structure, biosynthesis, and insect processing of alkaloids in conifers (pine, spruce, and fir trees). The structures of an array of 2,6-disubstituted piperidine alkaloids is found in the conifers are being elucidated by a combination of isolation, mass spectral analysis, and spectroscopic methods, as well as by synthesis and/or semisynthesis. Plant feeding experiments with carbon-13 labeled compounds appearing to be plausible biosynthetic precursors will elucidate details of the synthesis of these alkaloids. The ability of spruce species to generate trans-disubstituted piperidines, whereas pine species generate only cis-disubstituted compounds, will also be explored. Analysis of conifer-feeding beetle, butterfly, and moth larvae and their excretion products will determine how insects process the piperidine alkaloids. Finally, extracts of plants displaying activity against Mycobacterium tuberculosis will be analyzed in order to identify potential anti-tuberculosis agents. With support from the Organic Synthesis Program, Professor Frank R. Stermitz, of the Department of Chemistry of Colorado State University, studies the occurrence in conifers (pine, spruce, and fir trees) of compounds displaying biological activity. The particular `alkaloids` (naturally occurring nitrogen-containing compounds) found in these trees are found in similar or identical forms in an astounding variety of other natural sources, including the Mexican bean beetle, which synthesizes the alkaloids itself, and poisonous frogs, which obtain the alkaloids from unknown food sources. Study of both the plant sources of the alkaloids and the insects which feed upon them is expected to shed light on a number of important issues, including the way in which insects circumvent the defensive strategies of plants and possibly use ingested compounds to deter their own predators. In the course of related studies, plant extracts were isolated which display activity against the bacillus which causes tuberculosis. These extracts will be analyzed in order to identify new classes of compounds with potential therapeutic applications against strains of tuberculosis resistant to current drug therapies.
