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1.
Solvent-modified carbon dioxide extractions of the roots of Harpagophytum procumbens have been investigated with respect to extraction efficiency and content of harpagoside, and compared with a conventional extract. The effects of pressure, temperature, type and concentration of the modifier have been examined. Two extraction steps were necessary in order to achievehigh anti-inflammatory harpagoside-enriched extracts. The first extraction step was carried out in the supercritical state using carbon dioxide modified with n-propanol to remove undesired lipophilic substances. The main extraction was performed either in the supercritical or in the subcritical state with carbon dioxide modified with ethanol. The supercritical fluid extraction resulted in extracts containing up to 30% harpagoside. The subcritical extracts showed a harpagoside content of ca. 20%, but the extraction yield was nearly three times greater compared with supercritical conditions. The total harpagoside recovery resulting from the sum of the extract and the crude drug residue was greater than 99% in all experiments. The conventional extract and two carbon dioxide extracts were tested for in-vitro inhibition of 5-lipoxygenase or cyclooxygenase-2 biosynthesis. Both carbon dioxide extracts showed total inhibition on 5-lipoxygenase biosynthesis at a concentration of 51.8 mg/L. In contrast, the conventional extract failed to show any inhibition of 5-lipoxygenase biosynthesis.  相似文献   

2.
Response surface modelling, using MODDE 6 software for Design of Experiments and Optimisation, was applied to optimise supercritical fluid extraction (SFE) conditions for the extraction of indole alkaloids from the dried leaves of Catharanthus roseus. The effects of pressure (200-400 bar), temperature (40-80 degrees C), modifier concentration (2.2-6.6 vol%) and dynamic extraction time (20-60 min) on the yield of alkaloids were evaluated. The extracts were analysed by high-performance liquid chromatography and the analytes were identified using ion trap-electrospray ionisation-mass spectrometry. The method was linear for alkaloid concentration in the range 0.18-31 microg/mL. The limits of detection and quantification for catharanthine, vindoline, vinblastine and vincristine were 0.2, 0.15, 0.1 and 0.08 microg/mL and 2.7, 2.0, 1.3 and 1.1 microg/g, respectively. The dry weight content of major alkaloids in the plants were compared using different extraction methods, i.e. SFE, Soxhlet extraction, solid-liquid extraction with sonication and hot water extraction at various temperatures. The extraction techniques were also compared in terms of reproducibility, selectivity and analyte recoveries. Relative standard deviations for the major alkaloids varied from 4.1 to 17.5% in different extraction methods. The best recoveries (100%) for catharanthine were obtained by SFE at 250 bar and 80 degrees C using 6.6 vol% methanol as modifier for 40 min, for vindoline by Soxhlet extraction using dichloromethane in a reflux for 16 h, and for 3',4'-anhydrovinblastine by solid-liquid extraction using a solution of 0.5 m sulphuric acid and methanol (3:1 v/v) in an ultrasonic bath for 3 h.  相似文献   

3.
以硅藻金色奥杜藻(Odontella aurita)为实验材料,利用高效液相色谱法分析了其色素组成与含量,采取超临界CO2萃取技术研究了从干藻粉内提取岩藻黄素的条件。结果表明,该藻主要含有岩藻黄素、硅甲藻黄素、β-胡萝卜素、硅藻黄素等类胡萝卜素以及叶绿素a和叶绿素c1,其中岩藻黄素为该藻含量最高的类胡萝卜素。色素的萃取率与压强、温度、夹带剂含量以及萃取时间呈正相关,夹带剂含量对萃取率影响最大,CO2流速的影响最小;与有机溶剂法相比,超临界CO2萃取岩藻黄素效率略低,而更利于岩藻黄素的选择性萃取及分离提纯;岩藻黄素的SFE-CO2适宜条件为压强400 bar、温度50℃、CO2流速0.2 L/min、夹带剂比例10%、萃取时间2~3 h。  相似文献   

4.
Conventional solvent extraction methods cannot attain high‐quality antioxidant extracts from microalgae and also require solvent recovery and posttreatment. In this study, we utilized environmental friendly supercritical carbon dioxide fluid extraction (SFE‐CO2) techniques to obtain pigment (i.e. astaxanthin) from Haematococcus pluvialis. The effects of key operating parameters on the extraction efficiency of astaxanthin were investigated, giving an optimal condition of H. pluvialis weight, 6.5 g; CO2‐flow rate, 6.0 NL/min; extraction time, 20 min; extraction pressure, 4500 psi; volume of ethanol modifier added, 9.23 mL/g; extraction temperature, 50°C; modifier composition, 99.5%. Under these optimum conditions, the astaxanthin yield was 73.9% (10.92 mg/g dry H. pluvialis powder) after eight cycle of extraction cycles. The saponification index (CS/C0, representing the ratio of astaxanthin concentration after and before the saponification procedures) of the extract could be increased from 1 to 12.78 by saponification with 3.5 M NaOH.  相似文献   

5.
The highest yield (14.4 g/kg) of naringin, the major flavonoid from the peel of Citrus paradisi L., that could be achieved by supercritical fluid extraction was obtained using supercritical carbon dioxide modified with 15% ethanol and fresh (rather than dried) peels at 95 bar and 58.6 degrees C. This yield is higher than that attained by the conventional technique of maceration, and close to those obtained by reflux and Soxhlet methods. Furthermore, supercritical fluid extraction consumes less solvent and provides a shorter extraction time than conventional extraction methods.  相似文献   

6.
A method has been developed for the determination of vitamins A and E in food using supercritical fluid extraction (SFE), applying liquid or solid trapping, with an accuracy equal to conventional solvent extraction methods. Under optimal conditions, using methanol modified carbon dioxide as a supercritical fluid, Hydromatrix as a water adsorbent, and with a small amount of ascorbic acid and methanol added to the sample, the extraction time is reduced to 80 min. This time is considerably shorter than in conventional methods. Other advantages are the reduction of manual manipulations leading to lower labour costs and reduced consumption of organic solvents in the sample preparation step.  相似文献   

7.
The efficiency of carbon dioxide supercritical fluid extraction (SFE) of the biologically active compounds imperatorin, meranzin and meranzin hydrate from the fruit peel of Citrus maxima Merr. has been compared with that of solvent extraction with acetone. Under the best SFE conditions tested for the three coumarins, which involved extraction at 50 degrees C and 27.6 MPa, the extractive efficiencies were 84, 76 and 18% for imperatorin, meranzin and meranzin hydrate, respectively. The presence of modifiers significantly affected the extraction efficiency: the highest extraction efficiency of the three coumarins was obtained with ethanol as modifier.  相似文献   

8.
Opiates were extracted from sixteen hair samples of drug addicts using a supercritical fluid extraction method with supercritical carbon dioxide and a modifier solution of methanol-triethylamine-water (2:2:1, v/v). The concentrations, as determined by GC-MS, ranged from 1.22 to 21.73 (mean 7.60 ng/mg), 0.17 to 1.54 (mean 0.69 ng/mg) and 0.15 to 14.09 ng/mg hair (mean 3.78 ng/mg) for codeine, morphine and 6-monoacetylmorphine, respectively. The reproducibility of the total procedure had a relative standard deviation of 13%, 17% and 14% for codeine, morphine and 6-monoacetylmorphine, respectively. By this method, concentrations of 0.3, 0.2 and 0.1 ng/mg hair for codeine, morphine and 6-monoacetylmorphine, respectively, could be detected. Relative extraction recoveries were 61%, 53% and 96% for codeine, morphine and 6-monoacetylmorphine, respectively.  相似文献   

9.
以猴头菌子实体为原料,萃取物得率作为指标,采用CO2超临界流体萃取技术,以萃取压力和CO2流量等参数为考察因素,结合正交试验获得优化的萃取工艺:萃取压力为30MPa,温度为45℃,时间为1.5h,CO2流量为20g/min,夹带剂(乙醇)与猴头菌子实体的物料比为5:1(mL:g),在此条件下,萃取物得率为2.78%。与猴头菌子实体的醇提物相比,猴头菌子实体超临界萃取物具有更好的体外抗氧化能力和抗肿瘤活性,本研究结果为合理地开发和利用猴头菌子实体超临界萃取物产品提供科学的数据。  相似文献   

10.
北五味子果实超临界CO2萃取工艺的研究   总被引:11,自引:0,他引:11  
聂江力  裴毅  祖元刚 《植物研究》2005,25(2):213-215
通过正交设计的试验方法,探讨了超临界CO2法萃取五味子果实中木脂素的工艺条件,确定了最佳工艺条件为萃取压力30 Mpa,萃取温度50℃,萃取时间120 min。  相似文献   

11.
We describe a packed-column supercritical fluid chromatographic method that can be used for the analysis of isosorbide-5-mononitrate (5-ISMN) bulk substance and the 5-ISMN content of Imdur tablets. The method is based on methanol-modified carbon dioxide as the mobile phase and porous graphitized carbon (PGC, Hypercarb) as column support at 40 degrees C and 100 bar back pressure. The method makes it possible to simultaneously determine 5-ISMN and related compounds. In order to elute NO(3)(-) with acceptable retention time a quarternary ammonium hydrogen sulfate salt is added to the methanol modifier. An almost linear increase of the retention time with increasing carbon content of the counter ion was found. Tetramethyl ammonium hydrogen sulfate 5 mM in methanol was used in the final method as polar modifier for the simultaneous determination of possible degradation products within 12 min. The present method can separate and detect related compounds such as isosorbide-2, 5-dinitrate, isomannidemononitrate and isosorbide-2-mononitrate at the 0.1% (w/w) level as required by regulatory guidelines. Nitrate can be detected down to about 0.02% (w/w). Repeated analyses of ground tablet powder gave an assay precision for isosorbide-5-mononitrate of 1.4% (R.S.D., eight samples and two injections of each). For related substances at an area percent of 0. 1 the precision was less than 10%.  相似文献   

12.
为研究茯神挥发性成分含量、构成及其生物活性,本实验采用二氧化碳超临界的方法提取茯神低极性成分,以提取率作为响应值,在单因素试验的基础上采用响应曲面法考察提取压力、温度、二氧化碳流速对提取效果的影响,优化提取工艺。运用气相色谱-质谱联用仪(GC-MS)对其主要化学成分进行鉴定,并采用生长速率法测定了挥发油对5种真菌的生物活性。得到提取模型极值点,即提取压力27.26MPa、提取温度55.97℃、提取流速10.68L/min时,提取率达到最大,提取率预测值为1.66mg/g。通过NIST14质谱库检索,鉴定了其中17个主要化合物,运用峰面积归一法确定各个组分的含量,占挥发油总量的84.5%。抗菌实验表明茯神挥发油对采绒革盖菌菌株有低浓度促进高浓度抑制的活性。  相似文献   

13.
Globally there is an increasing concern to minimize the use of organic solvents, particularly the chlorinated ones because of their suspected human carcinogenicity. The use of ecofriendly carbon dioxide as an alternative to organic solvents would be appropriate in the perspective of green technology. Supercritical carbon dioxide (SC-CO(2)) extraction is suitable for extraction of nonpolar compound with molecular weights less than 400. Griseofulvin is an antifungal antibiotic having a molecular weight of 353, making it amenable to SC-CO(2) extraction. This work brings out the potential of supercritical carbon dioxide extraction (SCFE) for downstream processing of griseofulvin from the solid matrix obtained after solid-state fermentation (SSF). The optimized conditions for SCFE of griseofulvin from dried media after SSF were a flow rate of 0.4 L/min, temperature of 60 degrees C, and contact time of 90 min (30 min static + 60 min dynamic) at a pressure of 450-455 bar.  相似文献   

14.
利用超临界CO2萃取微孔草籽油,并对籽油进行了HPLC/MS分析。实验确定的最佳超临界CO2流体萃取条件是:萃取温度45℃,萃取压力20MPa,CO2流量为35-40kg/h,萃取时间120min,在此条件下白刺籽油的萃取率为16.12%。利用HPLC/MS对微孔草籽油分析,发现其不饱和脂肪酸的相对含量高达73.19%。比较了超临界CO2萃取微孔草籽油油样和石油醚萃取微孔草籽油油样的理化性质,发现超临界CO2流体萃取的籽油质量优于传统溶剂萃取的籽油。  相似文献   

15.
Off-flavors and unfavorable odors in tuna fish oil were successfully removed and identified using supercritical carbon dioxide extraction, while retaining variable compounds, polyunsaturated fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Samples of oil were extracted in a 100 mL semi-batch stainless steel vessel under conditions which ranged from 8 to 20 MPa and 20 to 60°C with solvent (CO2) flows from 10 g/min. GC-MS was used to identify the main volatile components contributing to the off-flavors and odors which included 2-methyl-1-propanol, 2,4-hexadienal, cyclopropane, and octadiene. Analyses of oil extracted at 40°C, 20 MPa showed a 99.8% reduction in dimethyl disulfide. Other significant off-flavors identified were 2-methyl-butene, 3-hydroxy butanal and ethylbenzene.  相似文献   

16.
The extraction of chamomile flowers using supercritical carbon dioxide was investigated with respect to extraction efficiency and compared with solvent extraction. The stability of matricine, a sensitive constituent of the essential oil of chamomile, in these extracts was studied during storage at different temperatures over 6 months. Matricine was stable at -30 degrees C. A slight decrease (80-90% recovery) occurred at +5 degrees C, whereas complete decomposition of matricine took place within 3-4 months at room temperature and at +30 degrees C, respectively. An in-line inclusion of chamomile constituents in beta-cyclodextrin (beta-CD) during the extraction process was assessed and inclusion rates between 40 and 95% were obtained depending on the amount of beta-CD and the type of chamomile constituent. No further stabilization of matricine in the carbon dioxide extract/beta-CD complexes was achieved. High residual water contents in the complexes even after freeze-drying were identified as accelerating the decomposition. In addition, the extractability of flavonoids, such as apigenin and apigenin-7-glucoside, was determined. Apigenin-7-glucoside, the more hydrophilic substance, was not extractable with pure carbon dioxide and showed a recovery of 11% using methanol modified carbon dioxide (18%, w/w) at 60 degrees C and 380 bar. Extraction conditions in the two-phase region of the binary mixture carbon dioxide-methanol (70 degrees C, 100 bar) led to a drastic change in fluid polarity and hence extractability increased to 92-95%.  相似文献   

17.
A rapid method has been developed for the simultaneous separation of the polar glycine- and taurine-conjugated bile acids by packed-column supercritical fluid chromatography. Samples were analysed on a cyanopropyl-bonded silica column with ultraviolet detection at 210 nm and carbon dioxide modified with methanol as the mobile phase. The influence of the stationary phase, modifier concentration, temperature, column pressure and modifier identity on retention was also studied. This new chromatographic method is applicable to the assay of conjugated bile acids in duodenal bile samples from patients with hepatobiliary diseases.  相似文献   

18.
A packed-column supercritical fluid chromatography/atmospheric pressure chemical-ionisation mass spectrometry (pSFC-APCI/MS) method has been developed for the determination of atropine from Atropa belladonna L extracts. The technique does not require any kind of derivatisation prior to the analysis. The optimum conditions were studied by using the pure substance in methanol (MeOH). All samples were simply dissolved in MeOH and injected into the mobile phase. Detection was achieved by using mass spectrometry (MS) with atmospheric pressure chemical ionisation (APCI). Terbutaline was used as an internal standard for the determination of the analytical reproducibility. The supercritical carbon dioxide (scCO(2)) mobile phase was modified by 15% MeOH containing 0.5% trifluoroacetic acid (TFAA) and 0.5% diethylamine (DEA) additives. Concentrations of atropine were determined with a relative standard deviation of less than 1% by the pSFC-APCI/MS procedure for a sample containing atropine and terbutaline. The correlation coefficient was 0.997 and detection limit 700 pg. The absolute retention time was 9.87 min with a standard deviation of 5.2x10(-3) min and a relative standard deviation of 0.61% with respect to terbutaline.  相似文献   

19.
为研究超临界CO2萃取茉莉花蕾获得精油的最佳工艺及抗氧化活性,实现资源的综合利用。实验考察了夹带剂用量、原料颗粒大小、萃取压力、萃取温度和动态萃取时间对茉莉精油产率的影响,进一步以响应面实验设计优化挥发油的提取工艺参数,以GC-MS分析挥发油组成及相对含量,并测定精油清除DPPH自由基及还原铁离子能力。结果表明,最佳工艺参数为:夹带剂乙醇用量为0.2mL/g,花粉颗粒为40目,萃取压力20MPa,萃取温度46℃,动态萃取时间1.6h。在此条件下茉莉精油的产率为13.67%,远高于同时蒸馏萃取法(2.87%)和超声辅助提取(2.45%)。超临界萃取精油的主要香气成分与茉莉鲜花基本一致,并且具有较好的清除自由基和还原铁离子能力。实验证明超临界萃取技术提取茉莉花蕾得到茉莉精油品质高,可为其资源综合利用提供参考。  相似文献   

20.
【目的】探讨黄荆Vitex negundo提取物对棉蚜Aphis gossypii的生物活性,并明确其中的有效成分,为进一步开发利用该杀虫植物提供理论基础。【方法】采用不同有机溶剂、超临界CO2萃取和水蒸气蒸馏3种提取方法,分别从黄荆的种子和叶片中提取活性物质。采用浸渍法测定了各提取物对棉蚜无翅成蚜的杀虫活性;并采用酸水提取法提取了其中的生物碱,采用毛细管点滴法测定黄荆生物碱对棉蚜生长发育及蜜露产生的影响。【结果】二氯甲烷种子提取物、甲醇种子提取物和水蒸气蒸馏得到的叶片精油对棉蚜无翅成蚜杀虫活性高,1 200 mg/L处理24 h校正死亡率分别达到86.98%,65.01%和85.27%。黄荆生物碱对棉蚜无翅成蚜有一定的忌避活性,20~40 mg/m L处理12 h时,忌避率在50%以上;对棉蚜无翅成蚜毒杀活性略低于黄荆种子二氯甲烷提取物,LD30浓度处理存活成蚜的产仔量和蜜露分泌量均较对照明显降低,处理到第10天棉蚜已经全部死亡,而对照组棉蚜第10天的存活率却为70%,生物碱处理后的9 d平均单雌棉蚜累计产仔量比对照减少了57.66%。排蜜频率、总排蜜量及单滴蜜露重量较对照处理组分别降低了13.18%,20.00%和8.79%。【结论】黄荆种子二氯甲烷提取物杀棉蚜活性最高,其中的生物碱是主要的杀蚜活性成分且对棉蚜生长发育及产仔和蜜露分泌具有一定的抑制作用。  相似文献   

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