Profiling of secondary metabolites produced by Colletotrichum coccodes pathogen of Tomato (Solanum lycopersicum L.) via gas chromatography–mass spectrometry (GC-MS)

Abstract

Studies on mycotoxins produce by Colletotrichum coccodes a pathogenic fungus responsible for anthracnose disease of tomato (Solanum lycopersicum) was conducted. C. coccodes was consistently isolated from three varieties of tomato on potato dextrose agar. For mycotoxin extraction the isolated and identified fungi was cultivated on Potato dextrose broth for 21 days and was sequentially extracted using methanol and n-hexane. Then the excess solvent was evaporated from the extract in a fume hood. The dried extract was then channeled to gas chromatography–mass spectrometry (GC-MS) analysis. The GC-MS chromatogram revealed the following secondary metabolites based on the corresponding peaks, which includes: n-hexadecanoic acid C₁₆H₃₂O₂, RT 13.55 min, 19.0% area), methyl palmitate C₁₇H₃₄O₂, RT 13.18 min, 9.7%), cis-9-octadecenoic acid, C₁₈H₃₄O₂, RT 13.74 min, 3.1%), methyl oleate (C₁₉H₃₆O₂, RT 14.59 min, 7.8%), 9,12-octadecadienoic acid, C₁₈H₃₂O₂, RT 14.55 min, 2.4%), and the p-Menth-8(10)-en-9-ol, C₁₀H₁₈O, RT 14.38 min, 1.3%). Many identified compounds have been reported to possess antimicrobial or insecticidal activities. These results provide the first GC-MS metabolite fingerprint for C. coccodes in this part of the world. The biological relevance of these compounds (innate antimicrobial effects) is discussed.