Antifeedant and Antifungal Activities of Metabolites Isolated from the Coculture of Endophytic Fungus Aspergillus tubingensis S1120 with Red Ginseng.

A new globoscinic acid derivative, aspertubin A (1) along with four known compounds, were obtained from the co-culture of Aspergillus tubingensis S1120 with red ginseng. The chemical structures of compounds were characterized by using spectroscopic methods, the calculated and experimental electronic circular dichroism. Panaxytriol (2) from red ginseng, and asperic acid (4) showed significant antifeedant effect with the antifeedant rates of 75 % and 80 % at the concentrations of 50 µg/cm2 . Monomeric carviolin (3) and asperazine (5) displayed weak attractant activity on silkworm. All compounds were assayed for antifungal activities against phytopathogens A. tubingensis, Nigrospora oryzae and Phoma herbarum and the results indicated that autotoxic aspertubin A (1) and panaxytriol (2) possessed selective inhibition against A. tubingensis with MIC values at 8 µg/mL. The co-culture extract showed higher antifeedant and antifungal activities against P. herbarum than those of monoculture of A. tubingensis in ordinary medium. So the medicinal plant and endophyte showed synergistic effect on the plant disease resistance by active compounds from the coculture of A. tubingensis S1120 and red ginseng.

The selective anti-fungal metabolites from Irpex lacteus and applications in the chemical interaction of Gastrodia elata, Armillaria sp., and endophytes.

The investigation of the metabolites from endophyte Irpex lacteus cultured in host "tian ma" (Gastrodia elata) revealed five new tremulane sesquiterpenes (1-5), and a new tetrahydrofuran derivative (6). Compound 1 was the first tremulane glucoside, and 6 possessed a rare tetrahydropyran-tetrahydrofuran scaffold. Main metabolite (2,3-dihydroxydodacane-4,7-dione, 14) from I. lacteus showed significant selectivity for antifungal activity against phytopathogen and endophytes associated with G. elata rather than against Armillaria sp. providing nutrition for the host G. elata. 14 accounted for 27.4% of isolated compounds from G. elata medium, and 69.3% by co-culturing with Armillaria sp. So the I. lacteus tended to promote the growth of Armillaria sp. in co-culture by producing 2,3-dihydroxydodacane-4,7-dione (14) to selective inhibit the phytopathogen and endophyte existed in host G. elata for the benefit of G. elata-Armillaria symbiosis. And the results were in accord with the real environment of G. elata depending on the nutrition of Armillaria. Some metabolites had anti-fungal activities against phytopathogens of G. elata with MICs ≤8 µg/mL.