芙蓉菊多糖体外抗氧化活性研究

目的研究芙蓉菊多糖的体外抗氧化活性。方法采用1,1-二苯基苦基苯肼(DPPH)自由基、还原力、超氧阴离子、羟自由基4种体外抗氧化模型研究芙蓉菊多糖的抗氧化活性,用维生素C作对照。结果芙蓉菊粗多糖对DPPH自由基、还原力、超氧阴离子、羟自由基均有明显的清除能力,其中DPPH、超氧阴离子、羟自由基的EC50值分别为0.273、0.669、0.594mg/mL,对羟自由基清除能力强于维生素C。芙蓉菊多糖对自由基清除率与其质量浓度存在着明显的量效关系。结论芙蓉菊多糖具有良好的体外抗氧化活性,作为天然抗氧化剂和自由基清除剂有进一步研究的价值。     

桂花不同溶剂提取物对氧自由基清除作用的ESR研究

目的研究桂花不同提取物对氧自由基的清除作用。方法利用不同极性溶剂（水、石油醚、乙酸乙酯、正丁醇）浸提桂花粉后得到不同极性的提取物。通过电子自旋共振（ESR）和自旋捕集技术,以1,1-二苯基-2-三硝基苯肼自由基（DPPH）及核黄素光照条件下产生超氧阴离子O2^-自由基体系,检测桂花中各组分清除DPPH自由基及O2^-的能力。结果以维生素C为对照,桂花水提取物、石油醚提取物、乙酸乙酯提取物、正丁醇提取物及维生素C清除DPPH自由基能力IC50分别为59.63,53.93,28.33,38.89,40.93μg·mL^-1;各提取物及维生素C对超氧阴离子O2-自由基清除能力IC50分别为63.37,55.47,30.20,48.36,41.52μg·mL^-1。其中各提取物的乙酸乙酯提取物的DPPH及O2^-清除率最大。结论通过比较各组分对DPPH自由基及超氧阴离子自由基的清除能力,了解桂花中抗氧化成分在各相中的分布情况,并据此进行有目的的分离桂花中的抗氧化成分。     

乌梅抗氧化作用的实验考察

目的:研究乌梅提取物抗氧化作用。方法:通过检测还原力和清除DPPH、ABTS和超氧阴离子自由基的能力,分析和评价乌梅提取物的抗氧化活性。结果:乌梅醇提物对DPPH、ABTS自由基的IC50分别为0.500 mg.mL-1及0.253 mg.mL-1;乌梅水提物对DPPH、ABTS自由基的IC50分别0.510 mg.mL-1及0.500 mg.mL-1;乌梅醇提物还原能力大于乌梅水提物,且乌梅醇提物对超氧阴离子自由基的清除作用显著,其清除作用优于乌梅水提物及对照品BHT。结论:乌梅提取物有不同程度的抗氧化活性,其中以醇提物抗氧化作用最强。     

5,7,4’-三羟基异黄酮基-8-对偶氮苯磺酸的合成及其抗氧化活性研究

目的合成未见文献报道的化合物5,7,4’-三羟基异黄酮基-8-对偶氮苯磺酸,并探讨其抗氧化活性。方法采用IR、1H-NMR、元素分析对其结构进行表征。利用荧光光谱法研究目标物对羟基自由基的清除活性,采用紫外光谱法研究目标物对超氧阴离子自由基和1,1-二苯基-2-苦肼基自由基(DPPH·)的清除活性。结果与结论目标化合物对1,1-二苯基-2-苦肼基自由基、羟基自由基和超氧阴离子自由基都有良好的清除活性,而且对羟基自由基的清除活性远高于对超氧阴离子自由基和1,1-二苯基-2-苦肼基自由基的清除活性。     

头花蓼抗氧化活性研究

目的:研究头花蓼抗氧化活性。方法:分别用石油醚、乙酸乙酯、甲醇提取头花蓼,用清除DPPH自由基、清除ABTS自由基和铁离子还原/抗氧化能力测定法,对头花蓼体外总抗氧化活性进行评价,并与6-羟基-2,5,7,8-四甲基苯并二氢吡喃-2-羧酸及阳性对照丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)比较。结果:头花蓼有较好的体外抗氧化活性。其甲醇提取物具有很强的清除DPPH自由基、ABTS自由基及还原Fe3+的能力,总抗氧化能力远远超过BHT的作用。结论:在3种提取物中,头花蓼甲醇提取物具有最高的抗氧化能力,乙酸乙酯提取物次之。3种方法中,DPPH方法和ABTS方法相关性(r=0.9917)最高。     

桂花不同溶剂提取物对氧自由基清除作用的ESR研究

目的 研究桂花不同提取物对氧自由基的清除作用。方法 利用不同极性溶剂(水、石油醚、乙酸乙酯、正丁醇)浸提桂花粉后得到不同极性的提取物。通过电子自旋共振(ESR)和自旋捕集技术,以1,1-二苯基-2-三硝基苯肼自由基(DPPH)及核黄素光照条件下产生超氧阴离子O₂^-自由基体系,检测桂花中各组分清除DPPH自由基及O₂^-的能力。结果 以维生素C为对照,桂花水提取物、石油醚提取物、乙酸乙酯提取物、正丁醇提取物及维生素C清除DPPH自由基能力IC₅₀分别为59.63,53.93,28.33,38.89,40.93 μg·mL^-1;各提取物及维生素C对超氧阴离子O₂^-自由基清除能力IC50分别为63.37,55.47,30.20,48.36,41.52 μg·mL^-1。其中各提取物的乙酸乙酯提取物的DPPH及O₂^-清除率最大。结论 通过比较各组分对DPPH自由基及超氧阴离子自由基的清除能力,了解桂花中抗氧化成分在各相中的分布情况,并据此进行有目的的分离桂花中的抗氧化成分。     

分光光度法检测马齿苋多糖的抗氧化活性

目的检测马齿苋多糖抗氧化活性。方法利用热水提取乙醇沉淀法制得马齿苋多糖,用分光光度法检测马齿苋多糖对1,1-二苯基-2-苦味酰基自由基（DPPH.）,羟自由基（OH.）和超氧阴离子自由基（O2-1）的清除能力。结果马齿苋多糖溶液对DPPH.自由基、OH.和O2-1均具有良好的清除作用,作用随剂量增加而增强。结论马齿苋多糖具有很大的开发利用前景。     

翁布中酚性化合物体外抗氧化活性的研究

目的 研究藏药翁布中13种酚性化合物的体外抗氧化活性.方法 采用DPPH自由基清除活性试验、FRAP法、ABTS法和酪氨酸酶活性抑制法评价13种酚性化合物的自由基清除能力及抗氧化活性.结果 没食子酸、3,5-二羟基-4-甲氧基苯甲酸清除DPPH自由基的半数抑制浓度(IC50)低于维生素C;FRAP法测定结果中,化合物阿魏酸、阿魏酸葡糖苷、咖啡酸、对羟基桂皮酸、没食子酸、3,5-二羟基-4-甲氧基苯甲酸的总抗氧化值均高于阳性对照Trolox;ABTS法测定结果中,化合物阿魏酸、松柏醇、阿魏酸葡糖苷、咖啡酸、对羟基桂皮酸、没食子酸、4-羟基-α-甲基苯丙醇、4-羟基-3-甲氧基苯甲酸的总抗氧化值相对于Trolox标准溶液均大于0.01 mmol· L-1;13种酚性化合物对酪氨酸酶均具抑制活性,但IC50均高于阳性对照曲酸.结论 阿魏酸、阿魏酸葡糖苷、咖啡酸、对羟基桂皮酸、没食子酸、3,5-二羟基-4-甲氧基苯甲酸具有较强的抗氧化活性.     

头状蓼提取物体外抗氧化活性研究

目的:研究头状蓼提取物的体外抗氧化活性。方法:以脂溶性维生素E及二丁基羟基甲苯(BHT)作对照,采用清除二苯代苦味酰基(DPPH)自由基、清除[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基和铁离子(Fe3+)还原/抗氧化能力(FRAP)测定法检测头状蓼石油醚、乙酸乙酯、甲醇提取物的体外抗氧化活性。结果:与头状蓼石油醚、乙酸乙酯提取物比较,头状蓼甲醇提取物清除DPPH自由基、清除ABTS自由基及还原Fe3+的能力较强。结论:头状蓼甲醇提取物具有较好的体外抗氧化活性。3种方法中,DPPH方法和ABTS方法相关性最高。     

何首乌及首乌藤抗氧化活性研究

目的评价何首乌和首乌藤体外总抗氧化活性。方法采用清除二苯代苦味酰基（DPPH）自由基、清除〔2,2′-连氨-（3-乙基苯并噻唑啉-6-磺酸）二氨盐〕（ABTS）自由基和铁离子还原/抗氧化能力（FRAP）测定法。结果将测定结果与水溶性维生素E（6-羟基-2,5,7,8-四甲基苯并二氢吡喃-2-羧酸,Trolox）及阳性对照二丁基羟基甲苯（BHT）进行比较,发现何首乌的乙酸乙酯和甲醇提取物具有较强的清除DPPH自由基、清除ABTS自由基及还原Fe3＋的能力。结论何首乌的总的抗氧化活性好于首乌藤。在6种提取物中,何首乌的乙酸乙酯提取物抗氧化能力最强。同一药用部位,甲醇和乙酸乙酯提取物的抗氧化活性好于石油醚提取物。3种方法之间有很好的相关性,以DPPH法与ABTS法相关性最好（R=0.996）。     

Free radical scavenging activity of red ginseng aqueous extracts

This study was performed to investigate the free radical scavenging activity of Panax red ginseng C.A. Meyer aqueous extract on 1,1-dipheny-2-picrylhydrazyl (DPPH), carbon-centered radical, hydroxyl and superoxide radicals using Electron Spin Resonance (ESR) spectrometer and spin-trapping techniques. Two different Red ginseng aqueous extracts prepared by boiling water or room temperature extraction exhibited no significant difference in free radical scavenging activity. Ginseng extracts completely eliminated DPPH radical at 2 mg/ml. About 0.5 mg/ml ginseng extracts quenched 80% carbon-centered free radicals generated from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Hydroxyl radical and superoxide radical were generated by UV irradiation and trapped by 5,5-dimethyl-l-pyrroline-N oxide (DMPO). Ginseng extracts scavenged 40% of hydroxyl radical at 0.1 mg/ml. Two mg/ml ginseng extracts completely scavenged superoxide radical. Ginseng extracts did not scavenge nitric oxide. The ESR data demonstrate that red ginseng aqueous extract is not a strong free radical scavenger.     

茉莉花挥发油清除自由基活性的研究

目的：从清除1,1－二苯基－2－苦苯肼自由基（DPPH?）、羟自由基（? OH）、超氧阴离子自由基（O2?－）3个方面,研究茉莉花挥发油清除自由基活性。方法采用水蒸气蒸馏法提取茉莉花挥发油,从其清除DPPH?、? OH和O2?－能力3个方面进行考察,并以常用抗氧化剂L－抗坏血酸为对照作比较,通过计算半数抑制浓度（ IC50）评价茉莉花挥发油清除,在供试质量浓度范围内,呈一定量效关系,其 IC50分别为153．548μg?mL －1、56．481μg? mL －1和133．586μg? mL －1。结论茉莉花挥发油具有良好的清除自由基活性,是一种新型天然抗氧化物质来源。     

Antioxidant and hepatoprotective actions of the medicinal herb Artemisia campestris from the Okinawa Islands

The antioxidant action of Artemisia campestris was examined in vitro and in vivo. A water extract of A. campestris showed a strong scavenging action of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals. When the extract was given intraperitoneally to mice prior to carbon tetrachloride (CCl4) treatment, CCl4-induced liver toxicity, as seen by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities, was significantly reduced. Depression of the elevation of serum enzyme levels after CCl4-treatment was also observed by oral administration of the extract. In that case, CCl4-derived lipid peroxidation in the liver was decreased by the extract treatment. These results suggest that the extract of A. campestris scavenges radicals formed by CCl4 treatment resulting in protection against CCl4-induced liver toxicity.     

低聚甘露糖醛酸磷酸酯的制备及其抗氧化活性探究△

目的 旨在探究不同取代度的低聚甘露糖醛酸磷酸酯的体外抗氧化活性。方法 采用磷酸-脲素法制备了3种不同取代度的磷酸化衍生物,然后测定了三种磷酸化多糖的体外抗氧化活性,包括清除超氧自由基、1,1-二苯基-2-吡啶酰肼(DPPH)自由基、羟基自由基及还原能力。结果 通过控制磷酸用量,制备了三种含磷量为3.90%、5.14%和6.56% 的单磷酸酯衍生物;与原料相比,低聚甘露糖醛酸磷酸酯衍生物的抗氧化活性增强;并且随着磷含量的增加,磷酸酯衍生物的羟基自由基、DPPH自由基清除活性及还原力也增强。结论 适当的磷酸化修饰可以显著提高低聚甘露糖醛酸的体外抗氧化活性,为海洋多糖的应用开发提供了借鉴。     

In vitro antioxidant activity and scavenging effects of Cinnamomum verum leaf extract assayed by different methodologies.

The free radical scavenging capacity and antioxidant activities of the methanolic extract of Cinnamomum verum leaf (CLE) were studied and compared to antioxidant compounds like trolox, butylated hydroxyl anisole, gallic acid and ascorbic acid. The CLE exhibited free radical scavenging activity, especially against DPPH radical and ABTS radical cation. They also exhibited reducing power and metal ion chelating activity, along with hydroxyl radical scavenging activity. The peroxidation inhibiting activity of CLE recorded using the linoleic acid emulsion system, showed very good antioxidant activity.     

Antioxidant Activities of the Chloroform Extract of Solanum trilobatum

A chloroform extract from the anticancer herb Solanum trilobatum (CST) (Nadkarni, 1979) was analyzed and compared with reference antioxidants for its in vitro antioxidative properties such as scavenging of α,α-diphenyl-β-picryl hydrazyl (DPPH) and superoxide radicals, protection to deoxyribose degradation, reducing power, as well as inhibition of lipid peroxidation. Preliminary phytochemical analysis of CST by silica gel thin-layer chromatography showed the presence of simple phenols, phenolic acids, isoflavones, xanthones, and lignans. The antioxidative effect of CST was found to be concentration dependent to a certain extent and then leveled off with further increase in concentration. The IC₅₀ for each antioxidative reaction studied was calculated. When compared to the reference antioxidant butylated hydroxytoluene (BHT), CST exhibited less scavenging effect on DPPH radicals and reducing power but a better superoxide radical scavenging effect. From a comparison of the hydroxyl radical scavenging effect of CST with catechin, it seemed that CST was four-times more effective than catechin. CST was also able to prevent the formation of ·OH-induced malondialdehyde (MDA) in rat liver homogenate.     

Antioxidant and drug detoxification potentials of Hibiscus sabdariffa anthocyanin extract

The antioxidant and drug metabolizing potentials of Hibiscus anthocyanin extract in CCl(4)- induced oxidative damage of rat liver was investigated. Hibiscus anthocyanin extract effectively scavenge α-diphenyl-β-picrylhydrazyl (DPPH) radical, superoxide ion, and hydrogen peroxide. It produced a 92% scavenging effect of DPPH radical at a concentration of 2.0 mg/mL. Hibiscus anthocyanin extract produced a 69 and 90% scavenging effect on superoxide ion and hydrogen peroxide, respectively, at 1.0 mg/mL, which compared favorably with the synthetic antioxidant (butylated hydroanisole and α-tocopherol). A reducing power of this anthocyanin was examined using K(3)Fe(CN)(6). Hibiscus anthocyanin extract has reducing power that is approximately 2-fold that of the synthetic antioxidant, butylated hydroanisole. Hibiscus anthocyanin extract produced a significantly increase and completely attenuated the CCl(4)-mediated decrease in antioxidant enzymes (e.g., catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase). However, the level of nonenzymic antioxidant molecules (i.e., vitamins C and E) were significant preserved by Hibiscus anthocyanin extract. There was an induction of phase II drug-detoxifying enzymes: glutathione S-transferase, NAD(H):quinone oxidoreductase, and uridyl diphosphoglucuronosyl transferase by 65, 45, and 57%, respectively. In view of these properties, Hibiscus sabdariffa anthocyanin extract can act as a prophylactic by intervening as a free radical scavenger both in vitro and in vivo as well as inducing the phase II drug detoxification enzymes.