Postinfectional inhibitors from plants. XXIII. Sesquiterpenoid phytoalexins from fruit capsules of Datura stramonium

Abstract

Datura stramonium fruit capsules inoculated with Monilinia fructicola or several other non-pathogenic fungi produced diffusates inhibitory to M. fructicola in spore germination assays. Detailed analysis of diffusates that are induced by M. fructicola indicated that they were complex and that antifungal activity was widely distributed through a number of column chromatographic fractions. Four compounds were isolated. These were sesquiterpenes, three of which, lubimin, hydroxylubimin, and capsidiol, have been described from other Solanaceae. The fourth, 2,3-dihydroxygermacrene, is a new compound with moderate antifungal activity but which is of especial interest as a possible precursor of several phytoalexins in the Solanaceae.

Genetic Analysis inGibberella pulicaris: Rishitin Tolerance, Rishitin Metabolism, and Virulence on Potato Tubers

“…Isolation of rishitin and lubimin. Sesquiterpene phytoalexins were elicited in potato slices (for rishitin and lubimin) and in immature seed pods of Datura stramonium (for lubimin only) with Helminthosporium carbonum Ulstrup (kindly supplied by H. D. VanEtten, Cornell University) with modifications of previously described methods (Lisker and Kuc 1977;Ward et al 1976). Lubimin was isolated by sequential column chromatography and thin-layer chromatography (TLC; Gardner et al 1988).…”

Defesas químicas de plantas: fitoalexinas

“…Essas substancias tern sido isoladas a partir de folhas e caules (INGHAM, 1976b;, frutos (WARD et al, 1976), tuberculos (BARNS et al, 1971), raizes (SUTHER-LAND et al, 1980) e flores (INGHAM, 1979).0 rendimento maior tern sido obtido atrayes da inocula~ao de frutos e sementes e 0 menor a partir de folhas, embora esse 6rgao seja bast ante utilizado. Segundo BAILEY (1982), a quanti dade de fitoalexi1!as produzida pode ser grandemente reduzida quando tecidos senescentes sao ensaiados.…”