Molecular docking and pharmacokinetic prediction of phytochemicals from Syzygium cumini in interaction with penicillin-binding protein 2a and erythromycin ribosomal methylase of Staphylococcus aureus

Introduction
MRSA and MLSB resistant S. aureus are known as important pathogens, which are responsible for many cases of both hospital and community-acquired infections worldwide. Studying drug discovery from plant sources is regarded as an important prevention strategy regarding these types of infections.

Material and methods
Agar well diffusion method was performed for antimicrobial evaluation, LCMS technique used for identification of different compounds, molecular docking performed by application of iGEMDOCK for PBP2a and ERM to plant compounds, and its pharmacokinetic evaluation of ADMET through use of AdmetSAR.

Results
Water extract was the most effective against resistant strains of Staphylococcus aureus. Twenty compounds belonging to phenols, flavonoids, organic acids, terpenoids groups were reported. Eighteen plant compounds passed in Lipinski's rule of five. iGEMDOCK revealed diferulic acid has the least binding energy −102.37 kcal/mole to penicillin-binding protein 2a and taxifolin has the least binding energy of −103.12 kcal/mole to erythromycin ribosomal methylase in comparison to control linezolid. These compounds raise the potential for developing potent inhibitors of penicillin-binding protein 2a and erythromycin ribosomal methylase for drug development. ADMET properties revealed that eighteen studied compounds were found in category III and IV with non-toxic properties except two butin and taxifolin found in category II with toxic properties.

Conclusions
It can be concluded that diferulic acid and taxifolin compounds provide the best inhibitor effect to PBP2a and ERM protein for inhibition of MRSA and MLSB resistant strains of S. aureus through the application of molecular docking, leading to a lead drug candidate for the treatment of diseases.