Chemical composition and antimicrobial activity of the leaf essential oils of Magnolia kwangsiensis Figlar & Noot growing in Vietnam

Abstract

The leaf essential oils of two individual trees of Magnolia kwangsiensis, growing wild in Bat Dai Son Nature Reserve, Ha Giang province of Vietnam, were obtained by hydrodisitillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Monoterpenoids (56.2% and 58.9%) and sesquiterpenoids (31.3% and 32.7%) were the main groups in both samples, the main compounds being (E)-β-ocimene (20.6% and 14.8%), myrcene (7.9% and 11.6%), and (E)-nerolidol (4.6% and 7.4%). Antibiotic activity of the essential oil samples was tested against three test microorganism strains using an agar disk diffusion method that showed the inhibition zones from 19.5–46.5 mm and 20–36.5 mm. Minimum inhibitory concentration (MIC) of the essential oils was determined using micro dilution broth susceptibility assay against seven test microorganism strains. MIC values of the essential oil from the first tree were from 4.1 to 16.4 mg/mL, while those from the second tree were from 8.2 to 16.4 mg/mL.