Antifungal activity of venenatine, an indole alkaloid isolated from Alstonia venenata

The indole alkaloid venenatine exhibited antifungal activity against some p lant pathogenic and saprophytic fungi. Venenatine in an aqueous acetic acid solution inhibited spore germination of all the 10 tested fungi; Fusarium udum, Alternaria brassicicola, Ustilago cynodontis and Aspergillus flavus s howed an especially high sensitivity towards this compound, exhibiting germ ination levels below 10 %. The spore germination and colony development of the parasitic fungus Erysiphe pisi, which causes powdery mildew in pea (Pis um salivum), on excised leaves of pea was also significantly affected. Pre- inoculation rather than post inoculation treatment of the leaves was more i nhibitory against spore germination and colony development.