Session: Undergraduate Research Posters: Organic Chemistry:

Pyrrolizidine alkaloids (PA's) are potentially toxic, naturally occurring secondary products often found in the plant family Heliotropiaceae. As part of a continuing investigation, two southeastern US Heliotropium species, H. angiospermum and H. polyphyllum, were studied to establish PA profiles. This is the first attempt to determine a PA description of either species. Preliminary TLC analysis using a polarity-based separation scheme indicates the presence of multiple compounds in both species. From H. angiospermum, NMR analysis of the most polar fraction reveals one major compound: a rare epoxy pyrrolizidine amino alcohol similar to the known compound subulicine. This compound has three chiral centers though their relative stereochemistry is not yet determined. NMR analysis of H. polyphyllum reveals one major compound: 9-angeloyl retronecine, though MS analysis also yielded a minor PA isomeric to the monoester intermedine. Further GC/MS and NMR analysis of both species may elucidate the presence of other structurally related PA's.

David Dill

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