厚朴叶不同极性溶剂萃取物总酚含量及体外抗氧化活性研究

为研究厚朴叶抗氧化活性成分,测定厚朴叶90%乙醇提取物及其石油醚、正丁醇、乙酸乙酯、甲醇萃取物和萃余相浓缩物的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除活性、2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐[2,2-azino-bis(3-ethylbenzthiazoline-6-sulonic acid),ABTS]自由基清除活性和总还原力,并与抗氧化剂2,6-二叔丁基-4-甲基苯酚(2,6-di-tert-butyl-4-methylphenol,BHT)、抗环血酸(VC)的抗氧化活性比较;同时测定厚朴叶乙醇提取物和不同极性部位中的总酚含量。结果发现:乙酸乙酯萃取物总酚含量最高,为(178.56±11.32)mg GAE/g,其含量高于正丁醇萃取物和90%乙醇提取物。厚朴叶乙醇提取物和不同极性部位均具有一定抗氧化活性,其中乙酸乙酯萃取物的抗氧化活性最强,DPPH自由基清除活性接近VC,显著高于BHT,其EC50为(86.27±0.02)μg/mL;对ABTS+自由基的清除活性接近VC和BHT;对Fe3+还原力较BHT低,但显著高于正丁醇萃取物。厚朴叶乙醇提取物和不同极性部位的抗氧化性与总酚含量呈显著相关性。采用薄层色谱-生物自显影法定性检测抗氧化活性,其结果与3种抗氧化测定方法的结果一致。综上,厚朴叶乙酸乙酯萃取物具有良好的抗氧化活性,可用于进一步分离抗氧化活性物质,具有发展为天然抗氧化剂的潜力。     

薏苡仁不同溶剂提取物体外抗氧化活性研究

研究了薏苡仁不同溶剂提取物体的外抗氧化活性,冷浸法制备薏苡仁乙酸乙酯提取物(EAE)、丙酮提取(AE)和乙醇提取物(EE),分别测定其对DPPH、ABTS~+自由基的清除率和铁离子还原能力。结果表明:薏苡仁3种提取物都具有一定的抗氧化活性,特别是乙醇提取物具有作为天然抗氧化剂和功能性食品进行研究和开发的潜力。     

黑蜂蜂胶不同极性提取物的体外抗氧化活性

目的:研究东北黑蜂胶不同极性提取物的体外抗氧化活性,确定其活性成分所在极性范围。方法:采用不同极性的溶剂提取黑蜂蜂胶,分别得到甲醇提取物(ME)、乙醇提取物(EE)、水提物(WE)、乙酸乙酯提取物(EA)、三氯甲烷提取物(CF)、苯提物(BE),考察其还原力、等价抗氧化能力(TEAC)、Fe3+还原能力(FRAP)及对羟自由基(·OH)、DPPH自由基的清除能力,比较不同极性提取物的抗氧化作用。结果:上述提取物均具有抗氧化活性,且呈显著量效关系,其抗氧化效果因反应体系的不同而不同。结论:东北黑蜂胶的甲醇和乙醇提取物的抗氧化活性较强,是天然抗氧化剂的良好来源。     

厚朴籽不同溶剂萃取物抗氧化活性比较分析

为研究厚朴籽抗氧化成分,测定厚朴籽90%乙醇粗提物及其石油醚、乙酸乙酯、正丁醇和水萃取物的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除活性,2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2-azino-bis(3-ethylbenzthiazoline-6-sulonic acid),ABTS)自由基清除活性和铁离子还原能力(ferric reducing antioxidant power,FRAP),同时测定其总酚及总黄酮含量。结果发现,乙酸乙酯萃取物的总酚和总黄酮的含量最高,含量依次为(253.64±7.25)和(179.11±0.61)mg/g。厚朴籽乙醇粗提物和萃取物具有一定抗氧化活性,其中乙酸乙酯萃取物的抗氧化活性最强,DPPH自由基清除活性显著(P<0.05)高于阳性对照BHT,其IC₅₀仅为(29.33±2.31)μg/mL;乙酸乙酯萃取物ABTS自由基清除活性与V_C相当,IC₅₀分别(30.33±1.53)和(31.67±3.06)μg/mL;厚朴籽乙醇粗提物和萃取物对铁离子的还原能力较低,均显著(P<0.05)低于阳性对照V_C和BHT。相关性显示,厚朴籽三种体外抗氧化活性均与总酚和总黄酮极显著相关(P<0.01)。以上结果表明,乙酸乙酯可以富集厚朴籽酚类物质,为下一步厚朴籽抗氧化物质分离奠定了理论依据。     

方格星虫提取物的抗氧化活性及成分分析

目的:对方格星虫的抗氧化活性进行研究。方法:方格星虫匀浆后于室温下用乙醇提取,然后用乙酸乙酯和水萃取,得到不同极性的提取物,分别对提取物进行抗氧化检测,同时与合成的抗氧化剂抗坏血酸(V_C)进行对照,并对有抗氧化活性的提取物进行化学成分分析。结果:实验结果表明水层提取物具有较好的抗氧化活性,乙酸乙酯层和乙醇提取物的抗氧化活性较弱;从乙酸乙酯层中分离鉴定出59个化合物,不饱和脂肪酸和甾体为主要成分;方格星虫水层具有多种成分,包括蛋白质、总糖、牛磺酸和SOD等。结论:不饱和脂肪酸、甾体、多肽、牛磺酸和SOD对方格星虫的抗氧化活性可能有一定的贡献。      

15种中草药提取物抗氧化活性的研究

用石油醚、乙酸乙酯、甲醇和水对所选定的15种中草药进行浸泡提取,采用Folin-Ciocalteu方法测定各提取物中的总酚含量;用DPPH和FRAP分析法评估了同溶剂提取物的抗氧化活性,并与2种参照抗氧化剂(抗坏血酸和BHT)进行比较。结果表明:不同中草药显示出不同的抗氧化活性,在15种中草药中以大花紫薇叶(LagerstroemiaSpeciosa)的抗氧化活性最高,其甲醇提取物中酚类物质的含量最高;同一种中草药的不同溶剂提取物显示出不同的抗氧化活性,通常甲醇提取物比石油醚、乙酸乙酯和水提取物有更强的抗氧化活性和更高的总酚含量。与参照抗氧化剂比较,大花紫薇叶甲醇提取物对DPPH自由基的清除能力强于抗坏血酸。     

交让木内生真菌JR0203代谢产物抗氧化及抑菌活性研究

目的:对交让木内生真菌JR0203菌株进行发酵培养,并对其代谢产物各提取物进行抗氧化和抑菌活性的研究。方法:用乙酸乙酯萃取发酵液,用甲醇、乙醇和乙酸乙酯依次提取菌丝体,然后采用清除DPPH自由基(DPPH·)法和Fe3+的还原力法测定各提取物的抗氧化活性,并采用牛津杯法测定各提取物的抑菌活性。结果:交让木内生真菌JR0203滤液乙酸乙酯提取物的乙酸乙酯部位有较强的抗氧化和抑菌活性。结论:本文为寻找植物源生物活性物质提供了实践基础和理论依据。     

几种紫草复合抗氧化剂的抗氧化活性研究

研究了紫草的乙酸乙酯提取物对花生油的抗氧化活性,发现紫草提取物具有显著的抗氧化活性。随后对紫草提取物与苏木、知母、七叶一枝花提取物的复合抗氧化剂的抗氧化活性进行了实验,结果显示这些复合抗氧化剂的抗氧化活性明显优于单一组分紫草及常用的合成抗氧化剂BHT。同时还研究了酒石酸对这些复合抗氧化剂的抗氧化活性的影响。     

松茸不同溶剂提取物及其抗氧化活性

对松茸不同溶剂提取物及其抗氧化活性进行了研究。依次用石油醚、三氯甲烷、乙醇及水提取,乙醇提取部分依次用乙酸乙酯和正丁醇萃取。采用DPPH自由基法、邻苯三酚自氧化法,以BHT、Vc为参照,分别研究松茸不同溶剂提取物的抗氧化活性,并对不同溶剂提取物中的总多糖、总黄酮及总多酚含量进行测定。结果表明:松茸不同溶剂提取物均具有一定的抗氧化活性,其中乙酸乙酯、水提取物的抗氧化活性较强,不同溶剂提取物的抗氧化活性与其总多糖、总黄酮和总多酚的含量具有一定的相关性。     

金钱草提取物的抗氧化活性及其成分研究

用1∶2的氯仿-甲醇超声提取金钱草成分,并用石油醚、乙酸乙酯和正丁醇依次进行萃取,利用Schaal烘箱法进行抗氧化实验,同时与合成抗氧化剂BHT进行对照。结果显示,乙酸乙酯提取物(EAF)具有最高的抗氧化活性,其活性大于人工合成抗氧化剂BHT。利用硅胶、RP-18和Sephadex LH-20对其进行活性追踪分离,得到3种纯的抗氧化成分。利用现代波谱技术对其化学结构进行了鉴定,结果显示为槲皮素、槲皮素-3-O-葡萄糖甙和山奈酚-3-O-葡萄糖甙。抗氧化活性顺序为:槲皮素>槲皮素-3-O-葡萄糖甙>山奈酚-3-O-葡萄糖甙>EAF>BHT。酚羟基化合物的抗氧化活性与其结构密切相关,活性大小主要取决于酚羟基的数目。     

姜油的提取及其对油脂抗氧化活性的研究

姜油是从生姜中提取的香精油,具有良好的抗氧化能力。在阐述了姜油化学成分的基础上,重点综述了姜油的提取方法、姜油的抗氧化活性以及影响其活性的有关因素。     

Effect of adding ascorbic acid and glucose on the antioxidative properties during storage of dried carrot

In this study, carrots were treated with ascorbic acid (0.1%) in a glucose (1.0%) solution (AA-Glu), and then freeze-dried and hot-air-dried to investigate the effects on their antioxidant content after 30 days of storage. The antioxidant components were extracted from the carrot samples using methanol. To assess antioxidative properties, tests measured the samples’ reducing power, α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating power. The above antioxidative properties of carrot extracts were compared with α-tocopherol and butylated hydroxyanisole (BHA). The analysis of antioxidant compounds included the total amount of ascorbic acid, total amount of phenolics, total amount of flavonoids, and carotenoids. The analysis showed that the samples immersed in AA-Glu solution prior to drying exhibited a higher antioxidative property than those not immersed.     

不同方法提取荔枝多糖抗氧化活性的比较

从铁离子还原能力、清除DPPH和ABTS+自由基能力三个方面比较了传统热水浸提的荔枝多糖和超声微波酶解协同提取的荔枝多糖的抗氧化活性,并以BHT(2,6-二叔丁基对甲酚)为阳性对照。结果表明,在实验浓度范围内,两种提取方法得到的荔枝多糖均有一定程度的抗氧化活性,且超声微波酶解协同提取的荔枝多糖的总抗氧化力和清除DPPH、ABTS+自由基的能力分别是热水法的2.00、6.40、7.83倍,是阳性对照BHT的24.65%、10.00%、12.49%,(p<0.05)。     

二氢杨梅树皮素的抗氧化活性研究

以植物油为研究材料，研究了二氢杨梅树皮素(DMY)的抗油脂氧化的能力；pH、溶剂、铁离子到其抗氧化性的影响。结果表明：DMY具有良好的抗油脂氧化的能力，抗氧化效果优于儿茶素、大豆异黄酮、翟根异黄酮，与TBHO的抗氧化效果相近；在0～0．1％的浓度范围内，其抗氧化效果随浓度增加而增强。DMY掘氧化作用的最适pH范围为4～5；乙醇溶的DMY抗氧化作用优于水溶的DMY的抗氧化作用。铁离子对DMY抗氧化性有一定的抑制作用，但可以通过提高DMY浓度得到改善；因此，DMY作为天然抗氧化剂有很好的开发前景。     

Antioxidant activity of minor components of tree nut oils

The antioxidative components of tree nut oils were extracted using a solvent stripping process. Tree nut oil extracts contained phospholipids, sphingolipids, sterols and tocopherols. The chloroform/methanol extracted oils had higher amounts of phenolic compounds than their hexane extracted counterparts. The antioxidant activity of tree nut oil minor component extracts were assessed using the 2,2-azino-bis (3-ethylbenzthiazoline sulphonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, β-carotene bleaching test, oxygen radical absorbance capacity (ORAC) and photochemiluminescence inhibition assays. Results of these studies demonstrated that extracts of chloroform/methanol extracted oils possessed higher antioxidant activities than extracts of their hexane extracted counterparts. Meanwhile the extract of chloroform/methanol extracted pecan oil possessed the highest antioxidant activity.     

Evaluation of antioxidative performance of tomato extracts obtained by different methods

BACKGROUND: Two extraction methods employing tetrahydrofuran and phosphate buffer (pH 7.4) respectively were used to process tomatoes. The antioxidant contents and antioxidative properties of extracts of four tomato cultivars were measured. To evaluate the overall antioxidative capacity of the tomato extracts, an antioxidative performance index (API) was used, defined as the average of four antioxidative assays, i.e. relative reducing power, ferrous ion‐chelating ability, 2,2‐diphenyl‐1‐picrylhydrazyl free radical‐scavenging activity and superoxide radical‐scavenging activity. RESULTS: A linear correlation between the total antioxidant content (TAC) and API of tomato extracts was found that was independent of the extraction method and tomato cultivar. CONCLUSION: The concept of representing multiple antioxidant activities by a single index is useful for evaluating the overall antioxidative capacity of antioxidants in tomatoes. Copyright © 2007 Society of Chemical Industry     

祁州漏芦水提物体外抗氧化活性研究

以高铁还原法检测祁州漏芦水提物(RUWE)的总抗氧化能力,以水杨酸法检测RUWE的羟自由基(.OH)清除率,以硫代巴比妥酸(TBA)法测定RUWE对肝线粒体的抗脂质过氧化作用。结果表明,RUWE的总抗氧化能力随其浓度增高而升高,呈量效关系。同时,RUWE浓度依赖性地清除羟自由基,抑制H2O2和Fe2+诱导的肝线粒体脂质过氧化作用。表明RUWE具有体外抗氧化活性。     

Assessment of endogenous antioxidative compounds and antioxidant activities of lager beers

BACKGROUND: Flavour stability is increasingly becoming the limiting factor in the shelf life of beer. Increasing the antioxidant activity of beer itself could suppress the rate of oxidative reaction and improve the flavour stability of beer. This report describes the levels of phenolic compounds, melanoidins and sulfur dioxide, and antioxidant activities of 40 lager beers. The relationships between antioxidative compounds and antioxidant activity were elucidated by multivariate analysis techniques. RESULTS: The results showed that the total phenolic content and the melanoidins content correlated well (P < 0.05) with antioxidant activity, while there was no significant correlation (P > 0.05) between total sulfur dioxide content and antioxidant activity. Satisfactory discrimination among beer samples with significantly different antioxidant activity was achieved by principal component analysis. Results from stepwise linear regression further demonstrated that different antioxidative components responsible for antioxidant activity were dependent on the assay used. The phenolic compound group is by far the most antioxidative compounds in beer and total phenolic content, melanoidins and sulfur dioxide together made a 22–68% contribution to the antioxidant activities of beers. CONCLUSION: Therefore, it might be an efficient means for brewers to increase total phenolic content during brewing for improvement in flavour stability of the final beer. © 2012 Society of Chemical Industry     

Antioxidative activity of (1→3), (1→6)-β-d-glucan from Saccharomyces cerevisiae grown on different media

In many microorganisms, fungi and algae (1→3), (1→6)-β-d-glucan can be found as cell wall polysaccharide. Various publications describe the strong positive influence of these glucans on the immune system comprising antibacterial, wound-healing and antitumour activities. Recently, it was found that (1→3)-β-d-glucan from the yeast Saccharomyces cerevisiae also exhibits antioxidative capabilities.In the present study, the antioxidative activity of glucan from the cell walls of S. cerevisiae grown on different media (wort, yeast-peptone-glucose, yeast-peptone-galactose) was investigated.Fermentation of the yeast took place on three different media. After fermentation the yeast was harvested and disrupted in a high-pressure homogeniser. Subsequently, glucan was extracted from the yeast cell walls by a procedure including a combination of hot water and enzymatic treatment. The level of (1→3), (1→6)-β-d-glucan in the cell walls was analysed enzymatically. The antioxidant activity was determined by electron paramagnetic resonance (EPR) spectrometry, TEAC assay (Trolox equivalent antioxidant capacity) and an ‘amperometric biosensor’.The results show significant differences in the glucan content of the cell walls and in their antioxidative activities depending on growth medium. However, glucan itself seems to have a low antioxidative activity in contrast to other cell wall fractions e.g. proteins.     

A comparative study on the antioxidative and anti‐allergic activities of fresh and aged black garlic extracts

The antioxidative and anti‐allergic activities of fresh and aged black garlic extracts were investigated. The garlic samples were extracted with 70% ethanol (v/v) and the total phenolic content was measured. The antioxidant capacity of extracts was assessed by determining the scavenging activities on 1,1‐diphenyl‐2‐picrylhydrazyl and hydroxyl radicals, ferricyanide reducing power, ferrous ion‐chelating ability and inhibitory effect on linoleic acid peroxidation. The anti‐allergic activity of extracts was analysed by measuring their inhibitory effects against β‐hexosaminidase release. The aged black garlic exhibited significantly higher phenolic content and greater antioxidative activity than fresh garlic. Both garlic extracts showed strong antioxidant capacity in a dose‐dependent manner. On the other hand, a considerably higher suppression of β‐hexosaminidase release was found in fresh garlic extract at lower concentration compared with that of the black garlic. Results of this study illustrate that ageing of garlic could enhance its antioxidant capacity, but could decrease its anti‐allergic activity.