Structures of Complexes of Gossypol with Ferrous Sulfate Based on High‐Performance Liquid Chromatography Separation, Spectroscopic Analysis, and PM3 calculations

Abstract

The complexes of gossypol with Fe2+ were prepared by using methanol as solvent in the presence of CO2 atmosphere. The results from FT‐IR spectra analysis indicated that the aromatic aldehyde groups in gossypol molecules were entirely involved in coordination with Fe2+. UV‐Vis absorption spectrum of the complexes in methanol solution displays blue‐shift in comparison with that of gossypol. Five compounds from the complexes were isolated by high performance liquid chromatography. The structures of the complexes are consistent with PM3 calculations. Two compounds were formed by coordination of gossypol with Fe2+ at 1:2 molar ratio, other three compounds were formed by chelation of gossypol with Fe2+ at molar ratio by 1:1, 1:3, and 1:4 respectively.