Erkan Naciye, Tao Zhou, Rupasinghe H P Vasantha, Uysal Burcu, Oksal Birsen S
Department of Environmental Sciences, Nova Scotia Agricultural College, P.O. Box 550, Truro, Nova Scotia, Canada B2N 5E3.
Nat Prod Commun. 2012 Jan;7(1):121-4.
Solvent-free microwave extraction (SFME) for the isolation of essential oil from leaves of Murraya koenigii L. (Rutaceae) has been compared with the conventional hydro-distilled oil (HD) in terms of yield, composition, antioxidant activity, and antibacterial activity against Listeria innocua. The yield of essential oil obtained from 30 min of SFME was similar to that of HD for 180 min. By GC-MS analysis, the major compounds of the essential oil extracted by SFME, which were obtained in somewhat lower amounts than in the essential oil obtained by HD, were alpha-copaene (44.3%), beta-gurjunene (25.5%), isocaryophyllene (12.1%), beta-caryophyllene (8.7%) and germacrene D (2.9%). The content of oxygenated terpenes, slightly higher for the SFME-essential oil (2.3%) than the HD-essential oil (1.4%), were much lower than that of nonoxygenated terpenes in both oils. DPPH radical scavenging activities of both essential oils were relatively low (10%-24%). Complete inhibition of growth of L. innocua was observed with both SFME and HD essential oils, at 400 and 600 microg/mL (minimum inhibitory concentration), respectively. The SFME-essential oil at 300 microg/mL provided 92% inhibition, indicating its potential as a natural antimicrobial agent.
采用无溶剂微波萃取法（SFME）从九里香（芸香科）叶片中提取挥发油，并在得率、成分、抗氧化活性以及对无害李斯特菌的抗菌活性方面，与传统水蒸馏法（HD）提取的挥发油进行了比较。SFME提取30分钟得到的挥发油得率与HD提取180分钟的得率相似。通过气相色谱 - 质谱联用（GC - MS）分析，SFME提取的挥发油中的主要成分（其含量略低于HD提取的挥发油）为α - 可巴烯（44.3%）、β - 古芸烯（25.5%）、异石竹烯（12.1%）、β - 石竹烯（8.7%）和吉马烯D（2.9%）。含氧萜类化合物的含量，SFME挥发油（2.3%）略高于HD挥发油（1.4%），但两种挥发油中含氧萜类化合物的含量均远低于非含氧萜类化合物。两种挥发油的DPPH自由基清除活性相对较低（10% - 24%）。分别在400和600微克/毫升（最低抑菌浓度）时，观察到SFME和HD挥发油对无害李斯特菌的生长均有完全抑制作用。300微克/毫升的SFME挥发油抑菌率为92%，表明其作为天然抗菌剂的潜力。
