Synthesis and Anti-Tobacco Mosaic Virus/Fungicidal/Insecticidal/Antitumor Bioactivities of Natural Product Hemigossypol and Its Derivatives.

To further study the structure-activity relationship of gossypol, hemigossypol ( 1 ) and its derivatives ( 2 - 23 ) were successfully designed via structure simplification and chemically synthesized. The anti-tobacco mosaic virus (TMV), fungicidal, and insecticidal activities of them were tested systematically. Most of these derivatives exhibited excellent anti-TMV activity. Furthermore, these compounds also exhibited broad-spectrum fungicidal activities against 14 kinds of phytopathogenic fungi. In particular, hemigossypol acid lactone ( 7 ) was stable in the air. In terms of biological activity, it not only showed anti-TMV activity (inhibitory rates of 70.3, 65.4 and 72.4% at 500 μg/mL for inactivation, curative, and protection activity in vivo , respectively) comparable to ningnanmycin but also exhibited higher insecticidal activity against mosquito larvae (60%/0.25 mg/kg) than the commercial species rotenone. None of hemigossypol and the tested derivatives showed antitumor activities.