GC-MS metabolic profiling and in silico molecular docking studies of the methanolic red rose (Papa meilland) petal extract for the investigation of potential antimicrobial effect

Papa meilland is a variety of medicinal plant belonging to the family Rosaceae, and it is well known throughout the world concerning its multiple therapeutic actions. The extract of its petals has proven to possess a broad spectrum of pharmacological effects involving antimicrobial, antidepressant, antifungal, antiseptic, anti-inflammatory, digestive stimulant, renal tonic and menstrual regulatory effects. Gas chromatography-mass spectrometry (GC-MS) profiling of the methanolic petal extract in this study revealed 89 compounds, and quinic acid was taken as the representative ligand to be used in subsequent in silico analysis due to its relatively high concentration among the antimicrobial candidates in the extract. The molecular docking was then done against Staphylococcus aureus DNA topoisomerase IV (PDB ID: 4URN ) and Escherichia coli DNA gyrase (PDB ID: 4PRX ) with ciprofloxacin serving as the reference drug. Quinic acid (QA) had binding affinities of -5.7 and -6.3 kcal/mol with 4URN and 4PRX, respectively, as opposed to -7.8 and -8.7 kcal/mol in ciprofloxacin. The stability of the protein-ligand complex was next investigated using molecular-dynamics simulations at 100 ns. The RMSD values obtained for 4URN_QA and 4PRX_QA complexes were, respectively, 1.181 ± 0.159 Å and 3.684 ± 0.636 Å, which indicates a stable and compact protein-ligand complex without significant unfolding. The ADMET and SwissADME analyses also indicated a good aqueous solubility, lack of mutagenicity and hepatotoxicity and generally good drug-like profile of quinic acid. Overall, the findings suggest that P. meilland red rose petals can serve as a promising source of naturally occurring antimicrobial compounds; however, further in vitro and in vivo studies are required to support the computational findings and confirm the therapeutic potential of quinic acid.