In vitro Antifungal and In silico Antibacterial Evaluations of Anacardic Acid and its Complexes from Cashew Nut Shell Oil

Abstract

Anacardic Acids (AcA) have been documented to have particularly important pathogenic properties. AcA and its complexes are being investigated in this article for their antimicrobial activities through in vitro and in silico assay methods. AcA from the cashew nut shell oil (CNSO) was isolated and Fourier-transform infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance ( 1HNMR) were used to characterise the compound. AcA complexes were synthesised with hydrated metal (II) ions of Cobalt and Copper in a ratio of 1:1 using a modified method by Mendes et al. The antifungal activities of these AcA metal complexes were tested against five fungi. While AcA showed no antifungal activity, its complexes showed interesting results. Anacardic acid complex of cobalt (AcA-Co) showed activities against three of the five fungi; the best activity was against Penicillium citrinum (30±7.07 mm); a better result than clotrimazole (12.5±0.71 mm) which was the reference standard drug used. Anacardic acid complex of copper (AcA-Cu) also showed activities against all fungi tested against except Aspergillus flavus with the best activity also against Penicillium citrinum (15±2.83 mm). Standard precision (SP) and extra precision (XP) docking of AcA with 1Y54 revealed that it inhibits Enterococcus spp. better than standard drugs (Streptomycin and Tetracycline) as shown by docking scores and degree of binding affinities. These results of AcA and its complexes suggest additional studies which could lead to the development of new antifungal and antibacterial agents.