CHEMICAL STUDIES OF SELECTED PLANT-DERIVED FERTILITY REGULATING AGENTS

Racemic gossypol has been resolved into its enantiomers by formation of the imine, bis- (R)-(+)-(alpha)-methylbenzyliminol -((+OR-))-gossypol, followed by resolution on a chiral stationary phase column. Acid hydrolysis of the resolved (-)-imine yielded (-)-gossypol. Three classes of amines yielded gossypol imino derivatives which were optically resolved on chiral columns. These amines included (1) bulky chiral amines e.g., R-(+)-(alpha)-methylbenzylamine, S-(-)-(alpha)-methylbenzylamine and dehydroabietylamine, (2) achiral long chain aliphatic diamine e.g., 1,10 diaminodecane, and (3) bulky achiral amines represented by benzylamine and p-fluorobenzylamine. The structure of all prepared or resolved gossypol imino derivatives were determined using physical and spectral characteristics. Further, two new methods have been developed for the analysis of total gossypol from plant materials. One method involved derivatization with 3-amino-1-propanol followed by HPLC analysis of the imino derivative using a mobile phase adjusted with a modifier THF: 0.005M sodium octylsulfonate (pH 3.4) on a C(,18) column. The other method involved similar derivatization but the product was acid hydrolyzed and analyzed directly by HPLC for gossypol. All forms of gossypol as well as gossypol-acetic acid, transformation products (anhydrogossypol), decomposition products, gossypolone and related analogs of gossypol have been successfully analyzed on a reverse phase C(,18) column with the mobile phases CH(,3)CN: H(,2)O: HOAc, 7:2:1 or 75:24:1. In addition the purity of gossypol-acetic acid was determined by HPLC and absorbance ratioing.;(+)-Gossypol was isolated from the stem bark of Montezuma speciosissima Sesse & Moc. ex DC. Hevea brasiliensis Muell. Arg. was shown to be devoid of gossypol. Gossypolone was seen to be unstable in acetonitrile and ethyl ether. However, it formed similar imino derivatives to gossypol. The acetylated product of ((+OR-))-gossypol was resolved by preparative HPLC into six hexaacetates which are isomers of the lactol and quinoid tautomeric forms. Further, gossypol in DMSO-d(,6) demonstrated the presence of all three tautomeric forms, aldehyde, lactol and quinoid.