Endophytic Fungi Penicillium species BCt Phytochemicals Inhibit Replication of Enzymes of Human Immuno-deficiency Virus 1 in in vitro and in silico Studies

Abstract

The present investigation was aimed to know the coumarins in the methanol extract of endophytic fungi, Penicillium species BCt isolated from Calophyllum tomentosum bark tissues using qualitative and GC-MS analysis. The endophytic extract was evaluated for anti-HIV activity on three replicating enzymes in vitro and in silico. The methanol extract of Penicillium species confirmed the presence of coumarins in four qualitative methods and yielded four different types of coumarins in GC-MS. In GC-MS analysis, totally seven different phytochemicals were identified based on retention time and compared with available library data. The four coumarins are coumarin (2H-1-benzopyran-2-one), coumaric acid (3-benzofuran-carboxylic acid), hynecromone (coumarin 4), 4-hydroxy-9-(3-methyl-2-butyl) furo (3,2-g) chloronen-7-one) and other three are common phytochemicals. The HIV-1 RT (98) was strongly inhibited by the endophytic fungal extract compared to integrase (118) and protease (158) in vitro analysis. Highest inhibition of integrase was observed with coumarilic acid (-17.62) when attached to Glu-35, Asn-38, Ser-39 amino acids. The protease was inhibited strongly by hymecromone (-16.39) when attached to amino acids of Val-77, Glu-34, Pro-79, Gly-78. The inhibition of RT was observed with coumarilic acid by attaching to Ala-445, Arg-567, Asp-456, Glu-478, Ser-499, Asn-474 (-23.54) significantly. Based on above results, the endophytic fungal coumarins have the ability to inhibit the three replicating enzymes of HIV-1 significantly. The in-silico results are evidence for how coumarins inhibiting the HIV replicating proteins by binding at specific amino acids. The results will help to understand how and where phytochemicals bind to target proteins to inhibit their action and it may help to identification of drugs to treat HIV. To validate our results, the in vivo research is needed.