In the C. personata groundnut A. hypogaea (susceptible cv. GG-11) interaction, NADPH oxidase enzyme activity was induced 24 hours after the inoculation which increased cons-tantly. On TLC profiling, one unique band was only found in disease state of groundnut having λ max at 305 nmt in UV spectral scanning. GC–MS study showed to be a Hexade-canoic acid methyl ester with molecular formula C18H36O2. The IR spectrum (KBr, ν, cm-1): 2852-2926 (aliphatic-C-H str.), 1603 (-C=O str.), 1120 (C-O ester str.) showed absorptions at 1603 and 1120 cm-1 indicating the presence of carbonyl and ester functional group respectively. The 1H NMR and The 13C NMR spectrum obtained were in agreement with present compound was Hexa decanoic acid methyl ester also called palmitic acid having molecular formula C18H36O2. Palmitic acid resulted in increased production of the NADPH oxidase and subsequent production of reactive oxygen species (ROS). Simultaneous presence of palmitic acid in disease state and induced activity of NADPH oxidase activity with enhanced disease incidence in groundnut shows relationship between palmitic acid and NADPH oxidase during pathogenecity. Thus, palmitic acid mediated induction of NADPH oxidase in groundnut might be the factor to focus to combat pathogenesis of C. personata.