Phytochemical Profiling and Anti-VanA Activity of Pulegone Extracted from Ziziphora tenuior Flower Against Vancomycin-Resistant Enterococci: An In Silico Approach.

Ziziphora tenuior is a herb known for its potent pharmaceutical activities. However, the specific compounds of the flowers of this herb have not been fully studied yet. This study used GC-MS to conduct a chemical analysis of the methanol and dichloromethane extracts of Z. tenuior flowers. Additionally, it sought to assess the potential antibacterial activity of the extracts against vancomycin-resistant enterococci (VRE) bacteria by predicting the interactions between one of the most prevalent compounds in the extracts and the D-alanyl-D-lactate ligase (VanA) protein, which is responsible for enterococci resistant to vancomycin. The results revealed a total of 15 compounds in the methanolic extract and 12 compounds in the dichloromethane extract. Among these, 5-methyl-2-(1-methylethylidene)-cyclohexanone, also known as pulegone, constituting 52.6 % of the methanolic extract and 34.6 % of the dichloromethane extract, was the most abundant compound in the extracts. Furthermore, the in-silico analysis demonstrated that pulegone exhibited significant interactions with VanA, as indicated by docking energy values of -7 kcal/mol and the formation of one hydrogen bond. The study suggests that pulegone shows promise as an antibacterial agent against VRE by potentially interacting with VanA protein and serving as a key inhibitor in fighting vancomycin resistance.