Separation and purification of secondary metabolites of Colletotrichum scovillei and the activity against Exserohilum turcicum

Two compounds ( 1 and 2 ) were isolated and purified from secondary metabolites of Colletotrichum scovillei by silica gel column chromatography, sephadex chromatography, thin layer chromatography and high-performance liquid chromatography. Their chemical structures were elucidated by spectroscopic technologies including nuclear magnetic resonance (NMR) and mass spectroscopy (MS). 1 was identified as a new ceramide 6-methyl-12-hydroxy-tetradeca-N-(2′,3′,4′-trihydroxybutyl)-2E,4Z-dienamide, and 2 was the known compound sambutoxin. Compounds 1 and 2 had good antifungal activity against Exserohilum turcicum, with EC₅₀ values of 11.43 μg/mL and 18.42 μg/mL, respectively. The results of in vitro leaf assay showed that at the concentration of 800 μg/mL, compound 1 had significant effects on northern corn leaf blight and the relative control efficacy was 84.8%, which was equivalent to that of chlorothalonil.