Synthesis, crystal structures and antibacterial activity studies of aza-derivatives of phytoalexin from cotton plant – gossypol

Using Gossypol (GOS) extracted from cotton seeds, a series of its Schiff bases (1–18) and hydrazones (19–27) have been synthesized and evaluated for their antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria and yeast-like organisms. Of the 27 aza-derivatives of gossypol, 11 have been found active against the microorganisms tested, similar to gossypol. Crystal structures of the new Schiff base (compound 7) and hydrazone (compound 25) of gossypol reveal the presence of two different tautomers within two types of the aza-derivatives studied. The newly synthesized aza-derivatives of gossypol are characterized by the FT-IR, NMR and MS methods.

Graphical abstract9 Gossypol hydrazones and 18 gossypol Schiff bases were prepared and evaluated for their antibacterial activity.Figure optionsDownload full-size imageDownload as PowerPoint slide