Phytochemical and antibacterial analysis of Pistacia integerrima: An integrated in vitro and in silico approach

Antibiotic resistance is a global concern due to the ability of bacteria to continuously develop various mechanisms of resistance against diverse antimicrobial classes; therefore, there is a critical prerequisite to discover diverse antibiotics with novel chemical structures and unique mechanisms of action. The research work aimed to investigate the detailed antibacterial activity and phytochemical characterization of the methanolic extract of Pistacia integerrima galls. Antibacterial properties were analyzed through the well diffusion method and the minimum inhibitory concentration (MIC) was determined through the broth dilution method. MIC of Pistacia integerrima extract (PIE) was found to be 10 mg/mL against both E. coli and S. aureus. Biofilm inhibition was determined by the crystal violet method where PIE demonstrated significant inhibition of biofilms. In the presence of PIE, TEM demonstrated morphological changes in both strains. A total of 17 metabolites were identified through GC-MS analysis with most of the compounds exhibiting antibacterial properties, HPTLC shows the presence of the important metabolite quercetin. Furthermore, virtual ligand screening revealed quercetin and phthalic acid as the most medicinally active constituents and potential inhibitors of tyrosyl-tRNA synthetase (TyrRS) and Dihydrofolate reductase (DHFR). Further research into PIE's bioactive compounds could lead to the development of new antibacterial compounds.