Isolation of (-)-gossypol from natural plant.

ABSTRACT

PIP: Both (+ and -)-gossypol and (+)-gossypol have been found to be naturally occurring, while no plant producing (-)-gossypol has to date been located. This study isolated (-)-gossypol from the cottonseed of Gossypium barbadense L. Cottonseed from G hirsutum L and G arboreum L was also investigated. The (-)-gossypol content was consistently higher than the (+) gossypol content for all 16 sample of G barbadense studied, while the (+)-gossypol content was higher in the 10 G hirsutum L samples and the 1 G arboreum L sample. The rotation property of gossypol was mainly correlated with the species of the cottonseed; the area where the cottonseed was cultivated had no effect. Gossypol isolated from G barbadense was always levorotatory as a result of the excess of (-)-gossypol, whereas that from the other 2 species studied was always dextrorotatory due to the excess of (+)-gossypol. The optical purity of gossypol isolated from G barbadense ranged from 10-25%, and that from G hirsutum varied from 10-20%.