Composition and Bioactivity of the Essential Oil from the Leaves of Lindera setchuenensis

Abstract

setchuenensis. In this study, we present for the first time the chemical composition and antibacterial activity of the EO from the leaves of Lindera setchenensis grown in China. Leaves of Lindera setchenensis were collected from Emeishan, Sichuan Province, China during May 2013. A voucher specimen (JRY01) was deposited at the Natural Products Chemistry Laboratory, Southwest Jiaotong University. Essential oil was obtained from the fresh material by hydrodistillation with a Clevenger trap. It was extracted three times with anhydrous ether and dried over anhydrous sodium sulfate. The yield of EO was 0.012% (m/m). GC-MS analysis of the EO was done with a Thermo Trace gas chromatograph equipped with a Polaris-Q external ion trap mass spectrometer. Data were processed by the HP MSD Chemistry Station, followed by the peak area normalization method to calculate the percentage of part of the chemical composition of the volatile oil. The EO was analyzed using an A DB-1 fused-silica capillary column (30 m 0.25 mm 0.25 m) with helium as carrier gas at 0.8 mL/min, and a split ratio of 1:30. The GC oven temperature was kept at 50C for 1 min, adjusted to 120C at a rate of 5C/min, then kept constant for 20 min. The temperature was then increased to 200C at a rate of 5C/min and then kept constant for 5 min, and again to 280C at a rate of 10C/min and then kept constant for 5 min. The injection port temperature was 250C, the column pressure was 40 kPa, and the injection volume was 1 L (95% in hexane). For mass spectrometry, an EI ion source at a temperature of 230C was used. The electron energy was 70 eV, the interface temperature was 280C with a solvent delay time of 3 min, and the scanning mass range was 20–450 m/z. Forty-nine of 79 compounds were identified, accounting for 78.97% of total composition (see Table 1). The volatile constituents of Lindera setchuenensis contained a high fraction of myristic aldehyde (6.7%), phytol (6.6%), linoleic acid (5.4%), and cis-13-octadecenal (5.4%). The content of the main constituent, palmitic acid, is 26.6%. There are only three constituents, 1,6,10-dodecatrien-3-ol, -elemene, and palmitic acid, were reported in the essential oil of L. glauca grown in Zhejiang Province, China, and the latter two compounds were similar percentage content in the essential oil of L. glauca and L. setchenensis [8]. The antibacterial activity of the EO against the strains Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 10231) as compared with that of amoxicillin (Table 2) was assayed using the agar disc diffusion method [9]. Final results are summarized in Table 2.