A STUDY ON PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF QUERCUS MACRANTHERA SUBSP. SYSPIRENSIS (K. KOCH) MENITSKY BRANCH AND LEAF EXTRACTS

Abstract

Objective: Oak species are medicinal plants with traditional use around the world. These species, which are very rich in tannins, have potential as antibacterial agents in terms of the polyphenolic compounds content. In this study, the antibacterial potential and phytochemical content of the branches and leaves of Quercus macranthera subsp. syspirensis, which is endemic to Turkey, were investigated. Material and Method: Plant materials were collected from Araç (Kastamonu/Turkey) in 2020. Methanol extracts were prepared from dried and powdered branches and leaves. The antibacterial activity test was evaluated by broth microdilution method as a minimal inhibition concentration (MIC) against Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis ATCC 35984, Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae ATCC 13883, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Acinetobacter baumannii ATCC 19606 and Bacillus subtilis ATCC 6633. The GC-MS analysis of extracts were performed using an Agilent 6890 gas chromatograph equipped with an Agilent 5973N quadrupole mass spectrometer (Agilent, USA). The compounds were identified by comparing the mass spectrum ratio of the sample with the data available in NIST 2014 Mass Spectral Library. Result and Discussion: As a result, it was found that the branch extracts were more effective than the leaf extracts and both branch and leaf extracts showed the highest activity against Bacillus subtilis ATCC 6633 strain (48.8 µg/ml, 97.6 µg/ml, respectively). The extracts also showed antibacterial activity at varying concentrations on other test strains.