Molecular docking analysis and evaluation of the antimicrobial properties of the constituents of Geranium wallichianum D. Don ex Sweet from Kashmir Himalaya

Abstract

Geranium wallichianum D. Don ex Sweet is a well-known medicinal plant in Kashmir Himalya. The evidence for its modern medicinal applications remains majorly unexplored. The present study was undertaken to elucidate the detailed antimicrobial promises of different crude extracts (methanolic, ethanolic, petroleum ether, and ethyl acetate) of G. wallichainum against common human bacterial and fungal pathogens in order to scientifically validate its traditional use. The LC–MS analysis of G. wallichainum yielded 141 bioactive compounds with the vast majority of them having therapeutic applications. Determination of minimum inhibitory concentrations (MICs) by broth microdilution method of G. wallichainum was tested against bacterial and fungal pathogens with MICs ranging from 0.39 to 400 µg/mL. Furthermore, virtual ligands screening yielded elatine, kaempferol, and germacrene-A as medicinally most active constituents and the potential inhibitors of penicillin-binding protein (PBP), dihydropteroate synthase (DHPS), elongation factor-Tu (Eu-Tu), ABC transporter, 1,3 beta glycan, and beta-tubulin. The root mean square deviation (RMSD) graphs obtained through the molecular dynamic simulations (MDS) indicated the true bonding interactions which were further validated using root mean square fluctuation (RMSF) graphs which provided a better understanding of the amino acids present in the proteins responsible for the molecular motions and fluctuations. The effective binding of elatine, kaempferol, and germacrene-A with these proteins provides ground for further research to understand the underlying mechanism that ceases the growth of these microbes.