Chemical composition, antimicrobial and antioxidant activities of Vateria indica L. oleo-gum resin (white dammar) essential oil

Abstract

White dammar is an oleo-gum resin obtained from Vateria indica L. (Dipterocarpaceae) and is known to possess diverse biological activities. This study examines the chemical composition, antimicrobial, and antioxidant activities of essential oil extracted from white dammar. The chemical constituents of essential oil were identified by gas chromatography coupled with mass spectrometry (GC-MS) and flame ionization detection (FID). A total of 18 compounds constituting 97.15% of the oil were identified, which consist of β-caryophyllene (36.32%), α-humulene (14.31%), β-humulene (9.73%), caryophyllene oxide (8.28%), allo-aromadendrene (5.63%) and junenol (5.1%). The antimicrobial activity of the essential oil obtained was measured by means of disc diffusion assay, minimum inhibitory concentration (MIC), and minimum bactericidal/fungal concentrations (MBC/MFC). The highest antimicrobial activity was shown against Bacillus cereus (MIC/MBC = 31.2/62.5 μg/mL) and also Staphylococcus aureus (MIC/MBC = 62.5/125 μg/mL), whereas only a moderate level of activity was recorded against Salmonella typhi (MIC/MBC = 125/250 μg/mL), Vibrio cholerae, MRSA (MIC/MBC = 250/500 μg/mL) and Candida albicans (MIC/MFC = 125/250 μg/mL). Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays; IC50 value, of 29.42 μg/mL and FRAP value, of 166.5 ± 2.2 μmol Fe2+/g indicated that the essential oil exhibited adequate antioxidant activity. These results substantiate the possible medicinal application of white dammar as an antimicrobial and antioxidant agent.