Mono-/Bis-Alkenoic Acid Derivatives From an Endophytic Fungus and Their Antifungal Activity.

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (-) and one known alkenoic acid derivative () were isolated from an endophytic fungi . Their chemical structures were identified by H-NMR, C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (-) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A () and fusaridioic acid D () are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against and the corn pathogen using the filter paper agar diffusion method. As a result, only compound decorating with -lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against showed the minimum inhibitory concentration (MIC) value of to be 20 g/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 g/ml. And the half maximal inhibitory concentration (IC) value (21.23 g/ml) of against was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC = 46.70 g/ml) as the positive control.