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白术挥发性成分的超临界流体萃取及其分析 总被引:5,自引:0,他引:5
采用超临界流体萃取白术挥发油成分,对萃取条件进行优化,并用气相色谱、气相色谱-质谱分析鉴定出超临界流体萃了的挥发油中22个化合物。最佳的超临界流体萃取条件为压力22.0MPa,温度60℃,0.5mL乙醇作改性,先静态萃取10min(CO2用量2.0mL),再动态萃取40min(CO2流速为0.3mL/min)。将超临界流体萃取与水蒸气蒸馏进行对比,水蒸气蒸馏5h的油收率仅为超临界流体萃取1h油收率的10.32%,证明超临界流体萃取替代传统萃取的必要性。 相似文献
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一种新型超临界流体萃取-高效液相色谱在线联用系统的构建 总被引:3,自引:0,他引:3
天然产物研究一直是植物学、化学和药学的重要研究领域.通过从天然产物中寻找生物活性成分和先导物是创制新药的有效途径之一.有效成分的提取是天然产物研究中最基本和最关键的环节.超临界流体萃取(Supercritical fluid extraction,简称SFE)是近年来发展较快的一种新型样品提取技术.超临界CO2作为最常用的萃取剂已被用于天然药物中非极性和弱极性有效成分的提取,尤其是挥发性和热敏性的物质.此外,通过加入适当的添加剂还可有效地萃取极性化合物,和传统的化学方法相比, 相似文献
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超临界流体萃取-高效液相色谱离线联用分析灵芝中三萜类化合物 总被引:6,自引:0,他引:6
在系统考察压力、温度和时间对萃取率影响的基础上,利用超临界流体萃取技术提取了灵芝子实体中的三萜类化合物。其最佳萃取条件为:压力15 MPa,温度35℃,动态萃取时间120 m in,CO2流量1 mL/m in,背压阀温度50℃。此外,还建立了高效液相色谱梯度洗脱分离三萜类化合物的方法。通过比较超临界流体提取物和甲醇提取物的色谱图,发现两者具有相似的峰形,说明超临界流体能够达到与甲醇相近的萃取效果,可以取代甲醇作为新一代的绿色萃取溶剂。 相似文献
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超临界流体萃取技术在提取中药挥发油中的应用 总被引:5,自引:0,他引:5
全健 《广东微量元素科学》2001,8(7):13-16
用超监介CO2流体萃取技术对多种中药挥发油的提取进行了综述,并将其与传统的水蒸馏法进行比较。结果表明,用超临界流体法不仅挥发油的收率高,而且提取时间也大大缩短。 相似文献
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Li Q Jiang C Zu Y Song Z Zhang B Meng X Qiu W Zhang L 《Molecules (Basel, Switzerland)》2011,16(10):8228-8242
Typhonium giganteum Engl. (BaiFuzi) is one of the herbs commonly used in traditional Chinese medicine against cancer. In our previous studies, 37 compounds were identified the SFE-CO(2) (supercritical fluid extraction with CO(2)) extract by GC-MS, including the four major components [β-sitosterol (40.22%), campesterol (18.45%), n-hexadecanoic acid (9.52%) and (Z,Z)-9,12-octadecadienoic acid (8.15%)]. The anti-cancer mechanisms of the SFE-CO(2 )extract from T. giganteum Engl. tubers have not been reported as yet. In this paper, the molecular mechanisms of the SFE-CO(2) extract-mediated apoptosis in SMMC-7721 cells were further examined. SFE-CO(2) extract inhibited the growth of SMMC-7721 cells in a time- and dose-dependent manner, arrested the cell cycle in the S phase and G2/M phase, and induced apoptosis. In addition, reactive oxygen species (ROS) increase, reduction of mitochondrial membrane potential, a rise in intracellular calcium levels were found in SMMC-7721 cells after treated with the extract. Western blot analysis showed that the extract caused down-regulation of Bcl-2 expression, and up-regulation of Bax expression. Moreover, caspase-3 and caspase-9 protease activity significantly increased in a dose-dependent manner. Collectively, our results showed that the SFE-CO(2) extract from T. giganteum Engl. tubers induces apoptosis in SMMC-7721 cells involving a ROS-mediated mitochondrial signalling pathway. 相似文献
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Contact toxicities of Acorus calamus L. (Arales: Araceae) extracts obtained from four published extraction methods: soakage, soxhlet, ultrasonic and supercritical fluid CO? (SFE-CO?), were compared in this study. Under the given extraction conditions, SFE-CO? extract exhibited the highest contact toxicity against S. zeamais of the four methods. With the SFE-CO? method, extraction temperature, pressure, time and the amount of EtOH (the extraction solvent) were identified as having a significant effect on the extract. Orthogonal experiments showed that the optimal extraction parameters were: temperature--55°C, pressure--35?MPa, time--40?min and EtOH--150?mL per 200?g of dry powder. Under these conditions, the yield was 4.12% and the LD?? of the extract against S. zeamais after 96?h of treatment was 27.26?μg?cm?2. β-asarone was the dominant component of the extract derived from the SFE-CO? method, accounting for 24.39% of the extract. These results may contribute to the designing of large-scale production processes for obtaining A. calamus extract, which proves to be an effective alternative for the control of stored product insect pests. 相似文献
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Carrara Vda S Serra LZ Cardozo-Filho L Cunha EF Torres-Santos EC Cortez DA 《Molecules (Basel, Switzerland)》2011,17(1):15-33
Piper amalago L. leaves were extracted with supercritical carbon dioxide and compressed propane under different conditions, and with chloroform by the conventional maceration method. These methods were compared for the pyrrolidine alkaloid content. Supercritical carbon dioxide (SFE-CO?) at 313 K and 12.55 MPa showed the highest selectivity for the main compound (600.53 mg/g of extract). A gradient high-performance liquid chromatography (HPLC) method was developed and validated to quantify the alkaloid N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine in the extracts. The HPLC method showed linearity, precision and accuracy, allowing the quantitative analysis of the alkaloid in all the samples. All the extracts were tested against the promastigote and intracellular amastigote forms of Leishmania amazonensis. The antileishmanial activity was evaluated in terms of inhibitory concentration for 50% of protozoa (IC??). The cytotoxicity was also evaluated against J774A1 macrophages, and the cytotoxic concentrations for 50% of macrophages were obtained (CC??). The SFE-CO? (313 K; 12.55 MPa) extract showed the highest antileishmanial activity with the following IC?? values of 16 and 7 μg/mL against the promastigotes and intracellular amastigotes forms, respectively. The extract showed low cytotoxicity with a CC?? value of 93 μg/mL. 相似文献
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Supercritical fluid extraction (SFE) with CO(2), a clean and rapid alternative to conventional organic solvent extraction techniques, was investigated for the extraction of 2,4-D from soils using a variety of pre-extraction soil treatments to enhance extraction recoveries. Initial experiments with silylation, ion-pairing, methyl esterification, and ionic displacement are reported. Methyl esterification and ionic displacement during SFE proved to be the most promising approaches for quantitative extraction. Although the SFE procedures were not fully optimized, comparison between SFE and a standard Soxhlet extraction method demonstrated the potential for improving analytical measurement for highly polar pesticides in soil by modifying SFE-CO(2) extraction with derivatizing reagents and ionic solutions. 相似文献
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The supercritical fluid extraction (SFE) of Lepidium apetalum seed oil and its anti-oxidant activity were studied. The SFE process was optimized using response surface methodology (RSM) with a central composite design (CCD). Independent variables, namely operating pressure, temperature, time and flow rate were evaluated. The maximum extraction of Lepidium apetalum seed oil by SFE-CO? (about 36.3%) was obtained when SFE-CO? extraction was carried out under the optimal conditions of 30.0 MPa of pressure, 70 °C of temperature, 120 min of extraction time and 25.95 L/h of flow rate. GC-MS analysis showed the presence of four fatty acids in Lepidium apetalum seed oil, with a high content (91.0%) of unsaturated fatty acid. The anti-oxidant activity of the oil was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and 2,2'-azino- bis(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) test. Lepidium apetalum seed oil possessed a notable concentration-dependent antioxidant activity, with IC?? values of 1.00 and 3.75 mg/mL, respectively. 相似文献
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Tse-Chiang Chang 《中国化学会会志》1996,43(1):1-5
The bonding nature of the canonical molecular orbitals 2σg, 2σu and 3σg in the molecules N2,O2, F2 and the related analogous molecular orbitals in the molecules P2 and CO, is analysed using Weinhold's natural bond orbital set. When the canonical molecular orbitals can be well localized into natural bond orbitals, the covalent bond can be completely attributed to the bonding type natural bond orbitals. The decomposition of canonical molecular orbitals into the natural bond orbital basis then gives the weighted bond order as the component of the bonding portion in the canonical molecular orbital. The weighted bond order results match the photoelectron spectroscopy assignment quite satisfactorily. 相似文献
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Xiaoqiang Bian Zhimin Du Yong Tang The State Key Laboratory of Oil&Gas Reservoir Geology Exploitation Engineering Southwest Petroleum University Chengdu Sichuan China 《天然气化学杂志》2011,(4):364-371
In order to study the effect of different CO2 contents on gas compressibility factor(Z-factor),the JEFRI-PVT apparatus has been used to measure the Z-factor of dry natural gas with CO2 content range from 10.74 to 70.42 mol%at the temperature range from 301.2 to 407.3 K and pressure range from 7 to 44 MPa.The results show that Z-factor decreases with increasing CO2 content in natural gas at constant temperature and increases with increasing temperature for natural gas with the same CO2 content.In addition,the Z-factor of water-saturated natural gas with high CO2 content has been measured.A comparison of the Z-factor between natural gas with and without saturated water vapor indicates that the former shows a higher Z-factor than the latter.Furthermore,Peng-Robinson,Hall-Yarborough,and Soave-Benedict-Webb- Rubin equations of state(EoS)are used for the calculation of Z-factor of high CO2 content natural gas with and without water vapor.The optimal binary interaction parameters(BIP)for PR EoS are presented.The measured Z-factor is compared with the calculated Z-factor based on three models,which shows that PR EoS combined with van der Waals mixing rule for gas without water and Huron-Vidal mixing rule for water-saturated gas,are in good agreement with the experimental data. 相似文献
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基于金属氧化物脱硫剂的天然气深度脱硫 《燃料化学学报》2013,41(10):1248-1255
确立了基于GC-MS和GC-SCD的天然气中超微量硫化物定性定量分析方法与条件,并分析了北京城市天然气中的硫化物。结果表明,天然气中含有三种硫化物,主要成分为四氢噻吩(THT),占总硫的94.2%。采用共沉淀法制备了ZnO/Al2O3脱硫剂,采用浸渍法制备了ZnO/γ-Al2O3、CuO/γ-Al2O3和CuO-ZnO/γ-Al2O3脱硫剂,并进行了天然气中THT深度脱除的实验研究。结果表明, 采用浸渍法制备的CuO/γ-Al2O3和CuO-ZnO/γ-Al2O3脱硫剂同时具有良好的低温活性和高温活性,可在50~500℃的宽温下将THT脱除至物质的量分数10×10-9以下,从而能够满足以天然气为燃料的分布式质子交换膜燃料电池电站对脱硫深度和脱硫温宽的要求。 相似文献