Synthesis, characterization and antioxidant activity of chitosan Schiff base derivatives bearing (-)-gossypol.

In this work, two new chitosan-Schiff base derivatives (HCS-GSP and LCS-GSP) were synthesized by the condensation reaction of high molecular weight chitosan (HCS) and low molecular weight chitosan (LCS) with (-)-gossypol (GSP), respectively. For this purpose, racemic gossypol was isolated from cotton seeds and it was further enantiomerically purified by diastereomeric resolution technique using l-tryptophan methyl ester hydrochloride. Then, chitosan polymers were derivatized with (-)-gossypol by the condensation reaction.