Profiling Secondary Metabolites of Cocoa (Theobroma cacao L.) Endophytic Fungi Lasiodiplodia pseudotheobromae PAK-7 and Lasiodiplodia theobromae TN-R-3 and Their Antimicrobial Activities
M. Chaithra
Department of Plant Pathology, TNAU, Coimbatore, Tamil Nadu, India and Department of Plant Pathology, CPCRI, RS, Vittal, Karnataka, India.
S. Vanitha *
Department of Plant Pathology, TNAU, Coimbatore, Tamil Nadu, India.
A. Ramanathan
Department of Plant Pathology, TNAU, Coimbatore, Tamil Nadu, India.
V. Jegadeeshwari
Department of Spices and Plantation Crops, TNAU, India.
V. Rajesh
Department of Plant Biotechnology, CPMB&B, TNAU, India.
V. Hegde
Division of Plant Protection, CPCRI, Kasaragod, Kerala, India.
E. Apshara
Department of Horticulture, CPCRI, RS, Vittal, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: To determine the chemical composition of secondary metabolite of cocoa endophytic fungi L. pseudotheobromae PAK-7, L. theobromae TN-R-3 and their anti-oomycete activities.
Statistical Design: Multivariate analysis.
Place and Duration of Study: Department of Plant Pathology, TNAU, Coimbatore, Tamil Nadu from April 2018 to December 2019.
Methodology: Lipophilic extracellular secondary metabolites were extracted using ethyl acetate as a solvent and their chemical composition was detected by Gas Chromatography-Mass Spectrometry (GC-MS) and identified by NIST library and Pub Chem databases.
Results: Metabolic profiling of cocoa endophytic fungi L. pseudotheobromae PAK-7 and L. theobromae TN-R-3 showed the presence of eleven peaks representing nine compounds. The most abundant compound observed were Acetic acid, 3-methyl-6-oxo-9oxabicyclo[3.3.1]non-2-yl ester, 2H-Pyran-2-one, tetrahydro-4-hydroxy-6-pentyl-, Melezitose, Ethyl à-d-glucopyranoside collectively representing 58.01% area. In comparison to L. pseudotheobromae PAK-7 GC-MS analysis of L. theobromae TN-R-3 exhibited the presence of 29 peaks. The most abundant compounds were dl-Mevalonic acid lactone, Methyl 6-O-[1-methylpropyl]-á-d-galactopyranoside, 2H-Pyran-2-one, tetrahydro-4-hydroxy-6-pentyl-, Melezitose, Ethyl à-d-glucopyranoside, 1,6-Anhydro-á-d-talopyranose collectively representing 60.47% of the total area.
Conclusion: Chemical compositions and anti-oomycete activities of crude secondary metabolites of L. pseudotheobromae PAK-7, L. theobromae TN-R-3 differed entirely depending on the property and abundance of bioactive metabolites.
Keywords: Endophyte, cocoa, metabolic profiling.