Pyrrolizidine alkaloids (PA’s) are potentially toxic, naturally occurring secondary products typically found in the plant family Boraginaceae. In this study, previously analyzed saturated monoester PA compounds, macrotomine and omphvernine, were analyzed using NMR and GCMS instrumentation. Results showed that the two compounds exhibited a number of structural similarities, but NMR analyses indicated stereochemical differences due to the presence of four stereocenters. NMR results previously established a trachelanthamidine based pyrrolizidine core but with significant side chain signal discrepancies. Conformational analysis using fine grid density functional theory will be used to create a set of lowest energy structures for each stereoisomer. Utilizing DP4 probability analysis as a stereochemical elucidation tool, these isomeric conformers will be compared to both experimental and literature NMR results with the intent to determine the absolute configuration of the stereoisomers.

Stereochemical assignment of pyrrolizidine alkaloids diastereomers using computational methods

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.