Studies on the mode of action of tomatine as a fungitoxic agent.
Removal of 1 or more sugar residues from the alpha-tomatine molecule markedly decreased its fungitoxicity. While partial hydrolysis of alpha-tomatine did not greatly affect its surfactant properties, it did destroy the ability of this alkaloid to form a complex with cholesterol. Only unprotonated alpha-tomatine was capable of binding cholesterol; the protonated form did not. Since alpha-tomatine was far more toxic at a high pH than at a low pH, this suggests that the unprotonated alkaloid is the active form and that it acts by complexing with fungal sterols.
D000470:Alkaloids / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D014053:Tomatine / Q000494:pharmacology
D000470:Alkaloids; D000935:Antifungal Agents; D014053:Tomatine