Four New Isocoumarins and a New Natural Tryptamine with Antifungal Activities from a Mangrove Endophytic Fungus L29.

Four new isocoumarin derivatives, botryospyrones A (), B (), C (), and D (), and a new natural tryptamine, (3a, 8a)-1-acetyl-1, 2, 3, 3a, 8, 8a-hexahydropyrrolo [2,3b] indol-3a-ol (), were isolated from a marine mangrove endophytic fungus L29, obtained from the leaf of . Their structures were elucidated using spectroscopic analysis. The absolute configurations of compounds , , and were determined by comparison of their circular dichroism (CD) spectra with the calculated data. The inhibitory activities of compound on , of compounds and on and , and of compound on , , and were higher than those of triadimefon, widely used as an agricultural fungicide. Compound was produced after using the strategy we called "using inhibitory stress from components of the host" (UISCH), wherein (2, 3)-3, 5, 7-trihydroxyflavanone 3-acetate, a component of with weak growth inhibitory activity towards L29, was introduced into the culture medium.