Submitted to: Phytochemical Society of North America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2011
Publication Date: N/A
Technical Abstract: Gossypol is a dimeric sesquiterpene that occurs in some members of the Malvaceae family. It occurs as an enantiomeric mixture in the foliage, seeds and roots of the cotton plant (<i>Gossypium</i>). It provides protection from insect and animal herbivory. Early studies demonstrated that gossypol is the product of cyclization of <i>E</i>,<i>E</i>-farnesyl diphosphate to (+)-delta-cadinene, which is converted to 8-hydroxy-(+)-delta-cadinene. Proposed intermediates beyond 8-hydroxy-(+)-delta-cadinene include desoxyhemigossypol and hemigossypol. At the time of its first discovery, hemigossypol was proposed to be the immediate precursor of gossypol; it was subsequently shown that hemigossypol is converted into gossypol by peroxidase, and 30 years later that a peroxidase in concert with a flower petal dirigent protein provides a 56% enantiomeric excess of (+)-gossypol. To complete the last step in the gossypol biosynthesis, a temporal study has now identified hemigossypol in developing cottonseed.