当归不同提取液中阿魏酸、咖啡酸含量及抗氧化作用的比较研究北大核心CSCD

为考察不同提取条件对当归提取液中阿魏酸和咖啡酸的含量及抗氧化作用的影响,本研究通过HPLC外标一点法检测当归提取液中阿魏酸和咖啡酸的含量,通过DPPH法和ABTS法检测当归提取液的抗氧化作用。研究结果表明,不同提取条件下当归提取液中阿魏酸的含量为0. 574～0. 707 mg/g,咖啡酸为0. 012～0. 082 mg/g;碱水溶液提取时阿魏酸与咖啡酸的含量最高,其抗氧化活性也最强,而95%乙醇提取时的含量最低,抗氧化活性最弱;提取溶剂随醇浓度的增加,咖啡酸的含量逐渐减少,阿魏酸的含量呈现先增加后减少的趋势,30%～50%乙醇提取时各组分有良好的协同抗氧化作用。     

虎刺抗氧化和抗菌活性研究

考察虎刺80%乙醇提取物和石油醚、二氯甲烷、乙酸乙酯、水溶性部位的抗氧化和抗菌活性以及与总黄酮含量的关系。乙酸乙酯部位在清除DPPH自由基和还原力模型中抗氧化活性最强,水溶性部位在总抗氧化力模型中抗氧化活性最强,而石油醚部位抗氧化活性最弱。二氯甲烷部位、乙酸乙酯部位和石油醚部位具有一定的抑菌活性。虎刺黄酮类成分可能是其抗氧化的物质基础。     

UPLC-MS测定千金子提取物的活性成分及其抗氧化性研究

目的：鉴定千金子乙醇提取物化学组成,探究其抗氧化活性,筛选活性化合物。方法：基于超高效液相色谱 飞行时间质谱（UPLC TOF MS）,数据库检索和文献比对等手段对其活性成分进行分析;采用DPPH和ABTS自由基清除法、β 胡萝卜素漂白法对提取物进行抗氧化活性评价。结果：共鉴定出17个化合物,包括青蒿亭、槲皮素 3 O 葡萄糖醛酸苷、山奈酚 3 O 葡萄糖醛酸苷、蔓荆子黄酮4个黄酮类化合物,瑞香素和双七叶内酯2个香豆素类化合物;千金子乙醇提取物对DPPH自由基和ABTS自由基的清除能力远大于BHT;对β 胡萝卜素的漂白作用弱于BHT。结论：千金子乙醇提取物中含有较丰富的水溶性黄酮类化合物和香豆素类化合物,表现出一定的抗氧化活性。     

当归不同提取液中阿魏酸、咖啡酸含量及抗氧化作用的比较研究

为考察不同提取条件对当归提取液中阿魏酸和咖啡酸的含量及抗氧化作用的影响,本研究通过HPLC外标一点法检测当归提取液中阿魏酸和咖啡酸的含量,通过DPPH法和ABTS法检测当归提取液的抗氧化作用。研究结果表明,不同提取条件下当归提取液中阿魏酸的含量为0. 574～0. 707 mg/g,咖啡酸为0. 012～0. 082 mg/g;碱水溶液提取时阿魏酸与咖啡酸的含量最高,其抗氧化活性也最强,而95%乙醇提取时的含量最低,抗氧化活性最弱;提取溶剂随醇浓度的增加,咖啡酸的含量逐渐减少,阿魏酸的含量呈现先增加后减少的趋势,30%～50%乙醇提取时各组分有良好的协同抗氧化作用。     

蛹虫草无性型菌丝体提取液体外抗氧化活性研究

分别测定了蛹虫草无性型菌丝体不同溶剂提取液在不同抗氧化模型中的抗氧化作用。结果表明,各种提取液对二苯基苦味酰基苯肼自由基(·DPPH)和羟自由基(·OH)均有显著的清除作用:在50mg/mL时,去离子水、70%乙醇和70%丙酮提取物对DPPH自由基的清除率分别为89.2%、83.6%和75.9%;70%乙醇提取物在30mg/mL时对·OH自由基的清除率达到100%;在50mg/mL时70%丙酮和去离子水提取物的·OH自由基清除率分别为95.6%和89.6%。在一定浓度下,各提取液对邻苯三酚自氧化也均有抑制作用;不同溶剂提取物的还原能力强弱为:70%乙醇>去离子水>70%丙酮。各种提取物的抗氧化组分不同,提取物浓度与抗氧化性成正相关。     

磨盘草提取物的抗氧化活性研究

目的:探究磨盘草乙醇提取物和甲醇提取物的抗氧化活性。方法:检测磨盘草乙醇提取物和甲醇提取物清除DPPH自由基能力和还原Fe~(3+)能力,评价并对比不同提取方法所得物质的抗氧化活性。结果:磨盘草乙醇提取物和甲醇提取物对DPPH自由基均具有较强的清除作用和较显著的还原Fe~(3+)能力,且随着提取液质量浓度的增加而增强。结论:磨盘草乙醇提取物和甲醇提取物均具有较强的抗氧化活性且与浓度呈现良好的量效关系。在一定质量浓度下乙醇提取物清除DPPH·能力比甲醇提取物强,甲醇提取物的还原Fe~(3+)能力比乙醇提取物强。     

藜芦杀虫活性的初步研究

先后以乙醇、氯仿和正丁醇为溶剂,提取了熊耳山区植物藜芦根茎中的活性物质。得到3个提取物:乙醇提取物、氯仿萃取物和正丁醇萃取物,产率分别为2.93%、1.14%和0.58%。测定了3种溶剂萃取物对粘虫、蚜虫、朱砂叶螨和蚊幼虫的毒杀活性。结果说明:这几种提取物都具有良好的毒杀效果。氯仿提取物对3龄粘虫有很强的拒食作用;乙醇提取物对4龄蚊幼虫的杀虫活性最高;3种溶剂萃取物对蚜虫的毒杀能力大小次序为:氯仿提取物>正丁醇提取物>乙醇提取物;对朱砂叶螨的毒杀力大小为:乙醇提取物>氯仿提取物>正丁醇提取物。采用试管反应法和层析法对藜芦根茎提取物进行化学成分预试,结果显示:乙醇提取物、氯仿提取物和正丁醇提取物中均含有生物碱类活性物质。     

云参化学成分研究——Ⅳ.云参、党参脂溶性成分和水溶性成分的薄层层析图谱比较

本文比较了云参和党参脂溶性成分和水溶性成分的薄层层析图谱。结果表明,云参、党参的脂溶性成分(乙醚、乙酸乙酯提取物)和水溶性成分(95％乙醇、水提取物、糖类成分)均基本相同,为云参代替党参使用提供了可靠的科学依据。     

花脸香蘑菌丝体提取物的体外抗氧化活性

分别测定花脸香蘑Lepista sordida发酵菌丝体不同浓度乙醇溶剂提取液在4种抗氧化模型中的抗氧化作用。结果表明, 各种菌丝体提取液对二苯基苦味酰基苯肼自由基(·DPPH)和羟自由基(·OH)均有显著的清除作用, 其清除作用随着乙醇溶剂浓度的提高而降低: 在3 g/L菌丝生药浓度时, 去离子水提取物对DPPH自由基和羟自由基的清除率分别为90.55%和81.9%; 在6 g/L菌丝生药浓度时, 50%乙醇和70%乙醇提取物对DPPH自由基的清除率分别为53.7%和45.2%, 对羟自由基的清除率分别为79.4%和78.4%。各菌丝提取物也具有极强的抗脂质过氧化能力, 在5 g/L菌丝生药浓度64 h内, 水提物、50%乙醇和70%乙醇提取物对亚油酸过氧化物的抑制率分别为100%、96%和89.2%。在一定浓度下, 各提取液对邻苯三酚自氧化也均有抑制作用。     

红背叶提取物的体外抗氧化活性

采用DPPH法、FRAP法、ABTS法和清除羟基自由基法四种抗氧化活性方法,测定了红背叶不同溶剂萃取60%EtOH提取物得到的部位清除自由基的能力.结果表明,乙酸乙酯提取物的抗氧化能力最强,强于阳性对照VC和Trolox;其次是60%乙醇提取物,其抗氧化能力基本与阳性对照BHA相当.     

Antioxidant content of oil and defatted meal obtained from borage seeds by an enzymatic-aided cold pressing process

Polyphenols content (as catechin equivalents) and tocopherol content were determined in borage defatted meal and borage oil, respectively. In addition, antioxidant activity of extracts obtained from borage defatted meal was evaluated. A cold pressing process was used for the extraction of Borago officinalis oil, resulting in a defatted meal (by-product). Polyphenols from this defatted borage meal were extracted using several solvents. An extract containing highly soluble solids and phenolic compounds with antioxidant activity (as free radical-scavenging, DPPH) was obtained when methanol was used. The tocopherol content was higher in oil extracted by cold pressing than in oil extracted with petroleum ether as organic solvent. An enzymatic treatment was applied (45 °C, 20% moisture, 0.25% E/S ratio, 1:1 Olivex:Celluclast enzymatic mixture) previously to borage oil extraction, which improved the antioxidant content in the borage defatted meal by three-folds, as compared to the values obtained by a nonenzyme-aided process.     

Lipid-soluble and water-soluble antioxidant activities of the avian intestinal mucosa at different sites along the intestinal tract

The antioxidant capacity of the avian intestinal mucosa is potentially important in protecting the gut wall from the harmful actions of reactive oxygen species originating from the diet, mucosal metabolism and the inflammatory response to enteric microbes. To assess this capacity, we determined the total lipid-soluble and water-soluble antioxidant activities of mucosal extracts, using tissue from different parts of the intestinal tract of the chicken. The lipid-soluble antioxidants, vitamin E and carotenoids, were also measured in the same samples. Total lipid-soluble antioxidant activity was highest in mucosa from the duodenum followed by the jejunum, with much lower activities in the ileum, ceca and colon. Total water-soluble antioxidant activity of the mucosa was at least an order of magnitude greater than the lipid-soluble activity under the assay conditions and did not differ significantly among the different parts of the intestinal tract. High concentrations of vitamin E were present in the mucosa of the duodenum and jejunum, with a trend to lower levels in the ileum and ceca, and significantly less in the colon. Similarly, the mucosa of the duodenum and jejunum contained the highest concentrations of carotenoids, with much lower levels in the ileum and colon. The different isoforms of vitamin E were absorbed from the digesta by the mucosa without any major selectivity. However, the liver was greatly enriched with alpha-tocopherol over the other isoforms, indicating a high degree of discrimination by this tissue. The results indicate major differences in the relative contributions of lipid- and water-soluble antioxidants in the mucosa along the different parts of the intestinal tract, most likely reflecting the sites of vitamin E and carotenoid absorption.     

Influence of the extraction solvent on antioxidant activity of Althaea officinalis L. root extracts

Althaea officinalis (Malvaceae) is a well-known plant that is widely distributed throughout the world. Aqueous and hydroalcoholic extracts from A. officinalis root are used mainly because of their antitussive and expectorant activity. It is well known that these activities are based on the polysaccharide composition, but little is known about the possible antioxidant activity of root extract. The present study evaluated antioxidant activity of root extracts prepared with different extraction solvents applying ABTS^·+ (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), hypochlorous acid scavenging assay and iron-induced lipid peroxidation. The results showed that the extract prepared with water as extraction solvent did not possess antioxidant activity, whereas the extracts obtained using ethanol:water as extraction agent showed well pronounced antioxidant activity. In particular, the extracts obtained at low concentration of ethanol in the mixed solvent (50:50 and 70:30, v/v) showed higher scavenging activity for ABTS^·+ radicals and hypochlorite ions than the extract obtained with the higher ethanol concentration (90:10, v/v). These results correlated very well with phenolic and flavonoid content of the extracts. The extracts did not show cytotoxic effect on human BV-173 leukemic cells but may have immunomodulating effects due to their antioxidant properties.     

黑灵芝提取物清除DPPH自由基的作用

以黑灵芝为研究对象,采用不同方法提取黑灵芝中的有效成分,以BHT和抗坏血酸为对照品,采用DPPH.法研究各种提取物对自由基的清除作用。结果表明:微波萃取法是最适合提取黑灵芝中有效成分的现代方法,不仅产率高,而且速度快,节能;不同溶剂提取物对DPPH自由基清除率强弱依次为95%乙醇>丙酮>水>氯仿,提取物用量与清除能力成量效关系;黑灵芝的丙酮提取物浓度达到1 mg/mL时已超过10 mg/mL BHT的抗氧化效果,相当于0.5 mg/mL浓度抗坏血酸的抗氧化效果。     

黄连抗氧化活性研究

利用DPPH、FRAP和ABTS三种抗氧化活性分析方法对黄连植物不同部位的有机溶剂提取部分进行抗氧化评价,将所测定结果与Trolox进行比较,发现黄连植物不同部位抗氧化活性不同。其中,黄连须根的抗氧化活性最高;同一部位中,乙酸乙酯和甲醇提取物抗氧化活性一般要高于石油醚提取物。在三种方法中,黄连不同部位的提取物清除自由基的能力均随浓度增大而增大;三种方法之间有很好的相关性,以FRAP法与DPPH法相关性最好(r=0.9261,P<0.01)。     

Investigation of Bolivian plant extracts for their radical scavenging activity and antioxidant activity

Fifty-four different extracts of nine Bolivian plants belonging to the family Asteraceae were evaluated for their radical scavenging activity by the DPPH*, NBT/hypoxanthine superoxide, and (*)OH/luminol chemiluminescence methods, and for their antioxidant activity by the beta-carotene bleaching test. The total phenolic content was also determined by the Folin-Ciocalteu method, and the oxidative stability by the Rancimat test. Both remarkably high phenolic content and radical scavenging and antioxidant activities were found mainly in the ethyl acetate fractions among the different plant extracts. Some ethyl acetate and even some defatted crude extracts exhibited activities comparable to those of commercial extracts/compounds, thus making it possible to consider some of the studied plants as a potential source of antioxidants of natural origin.     

Physical characteristics and antioxidant effect of polysaccharides extracted by boiling water and enzymolysis from Grifola frondosa

Grifola frondosa has been widely consumed in China and other Asian countries. Recent studies on G. frondosa have focused on the activities of polysaccharides extracted by water, and the activities of polysaccharides extracted by enzymolysis have not been studied. In this work, the relationship between the physical properties and antioxidant activity of polysaccharides extracted from G. frondosa by boiling water and enzymolysis was studied. Five polysaccharide extracts from the fruit body of G. frondosa were prepared by different extracting methods including boiling water, single enzyme enzymolysis with three different single enzymes (cellulose, pectinase, and pancreatin), and combined enzyme enzymolysis (cellulose:pectinase:pancreatin; 2:2:1). Characteristics such as the viscosity, Mw, polysaccharide content, protein content, infrared spectra, and antioxidant activities of the extracts were evaluated. The highest antioxidant activity was exhibited by the extracts prepared by combined enzyme extraction. The correlation analysis between antioxidant activity and polysaccharide content, protein content, Mw or viscosity indicated that the Mw had a more important role in antioxidant activity. Overall, the results indicate that the combined enzyme polysaccharide extracts can be developed as a new potential natural antioxidant.     

Enhanced in vitro and in vivo antioxidant activity and mobilization of free phenolic compounds of soybean flour fermented with different β-glucosidase-producing fungi

Aims:  To evaluate the soybean polyphenol glucosides bioconversion to aglycone forms by different β-glucosidases-producing filamentous fungi to enhance their antioxidant activity.
Methods and Results:  Soybean defatted flour was submitted to solid-state fermentation with Aspergillus niger , Aspergillus niveus and Aspergillus awamori . The fungi studied produced approximately the same β-glucosidase activity units amount when p- nitrophenyl-β- d -glucopyranoside was used as substrate for the assay. However, electrophoretic analysis, using 4-methylumbellipheryl-β- d -glucopyranoside as substrate, showed that β-glucosidase produced by A.   niveus was more active. Fermented methanolic extracts showed an increase in polyphenol and genistein contents and antioxidant activities. The highest genistein content was found in soybean fermented by A. niveus . Methanolic extracts of the soybean fermented by the different fungi showed a similar capacity of scavenging H₂O₂ generated in vivo by the tumour promoter 12- O- tetradecanoyl phorbol-13-acetate.
Conclusions:  A.   niveus synthesized a β-glucosidase with higher specificity to hydrolyse genistin β-glycosidic bond than those produced by A .  awamori and A. niger .
Significance and Impact of the Study:  The utilization of these β-glucosidases-producing fungi in soybean fermentation processes resulted in the obtaining of methanolic extracts with different antioxidant potentials that could be used either therapeutically or as an antioxidant in nonphysiological oxidative stress conditions, as the one induced in skin by UV radiation.     

麝香中脂溶性成分的提取与麝香质量鉴别

采用薄层层析和气相色谱技术,比较了超声、冷浸和热回流3种提取方法及乙醇、乙醚、正己烷3种溶剂对麝香提取液中脂溶性成分及麝香酮含量的影响。结果显示用不同提取方法和溶剂提取的麝香脂溶性成分经薄层层析后均呈现6或7个斑点。而经气相色谱分析,其结果却有较大的差别,麝香乙醚提取液的色谱峰较乙醇和正己烷更丰富,超声提取的效果较冷缦和热回流好,色谱峰达到20个。麝香酮的定量分析显示冷浸法提取的麝香酮含量高于超声和热回流提取。通过薄层层析和气相色谱分析,对10个麝香样品的质量进行了鉴别。