水蒸气蒸馏法与微波辅助萃取法提取天胡荽挥发油的比较研究

目的 比较水蒸气蒸馏(HD)与微波辅助提取(MAHD)天胡荽挥发油的化学成分.方法 采用水蒸气蒸馏法、微波辅助提取天胡荽的挥发油,用气相色谱-质谱联用仪( GC - MS)对提取物的化学成分进行分析.结果 在微波辅助提取和水蒸气蒸馏提取所得挥发油中,分别鉴定出了43种和39种成分,各占总峰面积的94.88％和93.63％.结论 两种提取法得到的挥发油主要成分基本相同,相对含量上有较大差别,微波提取的挥发油成分种类较多,提取效率高.     

Optimization and comparison of three methods for extraction of volatile compounds from Cyperus rotundus evaluated by gas chromatography-mass spectrometry

The essential oil of Cyperus rotundus has multiple pharmacological activities. Therefore, the extraction with high yield and quality is very important for preparation of essential oil of C. rotundus. In this paper, three methods, namely hydrodistillation (HD), pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE), for extraction of volatile compounds from C. rotundus were optimized and compared by gas chromatography-mass spectrometry. Among eight identified compounds in C. rotundus, five components including alpha-copaene, cyperene, beta-selinene, beta-cyperone and alpha-cyperone were quantitatively determined or estimated using alpha-cyperone as standard, which showed that PLE had the highest extraction efficiency, while SFE had the best selectivity for extraction of beta-cyperone and alpha-cyperone. The contents of ingredients from C. rotundus extracted with HD, PLE and SFE are significantly different, which suggest that comparison of chemical components and pharmacological activities of different extracts is helpful to elucidate the active components in C. rotundus and control its quality.     

Essential oil from Pterodon emarginatus as a promising natural raw material for larvicidal nanoemulsions against a tropical disease vector

The oleoresin obtained from fruits of Pterodon emarginatus was previously subjected to development of larvicidal nanoemulsions. To our knowledge, no efforts aiming at developing nanoemulsions with the essential oil from this species were carried out. This study describes the preparation and evaluation of the larvicidal activity of a novel oil in water nanoemulsion prepared with essential oil from fruits of P. emarginatus against Aedes aegypti larvae. β-caryophyllene is the major compound, corresponding to 25.8% of relative percentage of the essential oil. A series of nanoemulsions were obtained and better physical results were achieved using polysorbate 80, suggesting that a required Hydrophile-Lipophile balance value of this oil is around 15. Mean droplet size decreased from 128.0 ± 6.2 nm to 53.2 ± 0.5 nm, when surfactant to oil ratio increased from 1.0 to 2.0. The nanoemulsion prepared with P. emarginatus essential oil and polysorbate 80 (1:1) was able to induce mortality on early 4th instar larvae. This study allowed preparation of nanoemulsions with essential oil from fruits of P. emarginatus for the first time, which proved to be a potential larvicidal against Aedes aegypti. The utilization of a low cost and solvent-free method can be considered an advantage in terms of potential applications of this natural product in ecofriendly integrative practices of vector control. Moreover, the great potential of this plant species is highlighted by the fact that its fruits can be obtained by a sustainable management of biodiversity, using the concept of standing trees to protect and stimulate conservation of the species.     

Comparison of chemical constituents and antimicrobial activities of three essential oils from three different brands' clove samples collected from Gulf region

ObjectiveTo analyze three essential oils isolated from three different brands' clove samples collected from Gulf region and tested their antimicrobial activities.MethodsThe essential oils were isolated from powder clove samples by water distillation method and analyzed and identified by gas chromatography-mass spectrometry. Antimicrobial activities of the three isolated essential oils were calculated on the diameter inhibition zone by disc diffusion method against three bacterial strains with amoxicillin standard.ResultsTwenty-eight, twenty-two and twenty-six chemical ingredients with high percentage were characterized based on gas chromatography retention time from clove essential oils collected from Saudi Arabia, United Arab Emirate and Jordan. The highest antimicrobial activity was obtained from Saudi Arab against Escherichia coli, Pseudomonus aeruginosa and Staphylococcus aureus and the lowest was from Jordan and the order of antimicrobial activity was Saudi Arabia>United Arab Emirate>Jordan.ConclusionsAll three essential oils from Gulf region are containing very portent chemical ingredients and it could be used as medicine or antibiotics for different aliments.