DOI: https://doi.org/10.55373/mjchem.v27i1.236

Keywords: Dipterocarpus kerrii; phytochemical constituents; antibacterial activity; Bacillus cereus; Staphylococcus aureus

Abstract

Dipterocarpus is the third most diverse genus within the Dipterocarpaceae family. In addition to its importance in timber production, this genus exhibits a wide spectrum of bioactive properties due to the presence of resveratrol oligomers, terpenoids, flavonoids, and other phenolic compounds. In this study, Dipterocarpus kerrii was selected for phytochemical investigation and the examination of the antibacterial properties of its crude extract against Bacillus cereus (B. cereus) and Staphylococcus aureus (S. aureus). Acetone maceration of the granules (650 g) from the twigs of D. kerrii yielded a crude acetone extract (178 g). Fractionation of the crude extract via VLC resulted in four semi-purified fractions (DK 1-4). Purification of the fractions using several chromatographic methods has yielded two pure compounds. The structural elucidation of the purified compounds was accomplished by spectroscopic analyses and comparison with literature data. The compounds were identified as apigenin (1) (5 mg) and scopoletin (2) (4 mg). The antibacterial activity of the crude acetone extract was assessed using disk diffusion and minimum inhibitory concentration (MIC) test. The results indicated that the crude acetone extract of D. kerrii demonstrated antibacterial properties against both B. cereus and S. aureus. At 50 mg/disc, the inhibition zones on B. cereus and S. aureus were 11.0 + 1.00 and 13.6 + 1.15 mm, respectively. Meanwhile, the MIC values of B. cereus and S. aureus were 1.56 mg/mL and 0.78 mg/mL, respectively.