艾叶多糖的提取、含量测定及对羟自由基清除作用的研究

目的:探讨艾叶多糖的提取、含量测定及其对羟自由基(·OH)的清除作用.方法:采用热水浸提法提取艾叶多糖并进行初步纯化;苯酚-硫酸法测定其含量;·OH清除实验观察艾叶多糖对·OH的作用.结果:样品中多糖含量为2.56%,回收率为98.45%,RSD = 0.391%(n = 5),其纯度和产率均较高;艾叶多糖溶液对由Fenton体系产生的·OH有一定的清除作用,随着艾叶多糖浓度的增加,对·OH自由基的清除能力也增强.结论:艾叶中含有一定量的多糖;艾叶多糖对·OH具有较好的清除作用,在一定范围内呈现良好的量效关系.     

蒲公英根多糖的抗氧化活性研究

目的:提取蒲公英根中多糖,测定其多糖含量和体外抗氧化作用。方法:超声波协同酶法提取蒲公英根中的多糖,苯酚-硫酸法测定多糖的含量,以维生素C为对照,采用分光光度法测定蒲公英根多糖对OH·和O-2·自由基的抑制作用,HPLC法检测DPPH·的浓度法测定蒲公英根活性多糖清除DPPH·自由基的能力。结果:蒲公英根中的多糖含量为83.31%,清除OH·、O-2·和DPPH·的IC50值分别为:0.047mg/mL,0.01mg/mL,0.154mg/mL。结论:蒲公英根多糖对OH·、O-2·和DPPH·自由基均有良好的清除能力。     

鲍鱼脏器粗多糖体外抗氧化活性研究

目的提取鲍鱼脏器粗多糖并研究其抗氧化活性。方法以鲍鱼脏器为原料,采用高压脉冲电场(PEF)技术辅助酶法提取鲍鱼脏器粗多糖(Abalone viscera crude polysaccharide,AVCP)。体外测定AVCP的总还原能力、羟自由基(.OH)清除能力、超氧阴离子自由基(O2-·)清除能力;并采用H2O2诱导的HepG2细胞氧化应激模型,通过MTT法检测给药处理后氧化损伤细胞存活率,同时测定丙二醛(MDA)含量、超氧化物歧化酶(SOD)活力。结果AVCP的还原能力与多糖浓度呈一定的量效关系;AVCP对·OH和O2-·的清除率与浓度呈一定的剂量依赖性,在多糖浓度为10mg/mL时,对·OH的清除率达到25.25%;高浓度AVCP对O2-.具有微弱的清除作用,20mg/mL时对O2-·清除率为25.40%;MTT实验结果显示,氧化应激模型组细胞存活率为71.59%,在终浓度为10～80μg/mL范围内,AVCP可将氧化损伤细胞存活率由71.59%提高至84.32%;与氧化应激模型组相比,经终浓度为10～80μg/mL的AVCP处理后,各组MDA含量均显著降低(P<0.01),且呈良好剂量依懒性;各组SOD活力显著提高(P<0.01)。结论所提取鲍鱼脏器粗多糖具有一定的抗氧化活性。     

猪仔笠多糖成分的提取及抗氧化活性研究

目的建立猪仔笠中多糖的提取方法 ,并对其抗氧化活性进行研究,为猪仔笠的资源开发及应用提供实验依据。方法利用经典水提醇沉法,从猪仔笠中提取多糖成分,并利用苯酚-硫酸法测定多糖的含量,分别采用水杨酸法和邻苯三酚自氧法测定多糖对羟基自由基(.OH)的清除作用以及对超氧阴离子自由基(O2-)的清除作用。结果实验结果表明利用石油醚连续回流提取,能够提取出猪仔笠中的多糖成分,含量为7.03%;在多糖浓度为1600μg.mL-1时,对羟自由基清的除率可达到70.92%,对超氧阴离子自由基(.O2-)的清除率达到53.19%。结论猪仔笠中的多糖具有显著的抗氧化活性。     

马齿苋多糖清除羟自由基作用的研究

目的检测马齿苋多糖清除羟自由基作用。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-苦肼基自由基（DPPH？）,羟自由基（OH？）和超氧阴离子自由基（O2-1）的清除能力。结果与结论马齿苋多糖溶液对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。     

天麻多糖的分离纯化与抗氧化活性研究北大核心CSCD

目的从天麻中分离纯化出活性多糖并考查其抗氧化活性。方法用水提醇沉法提取天麻粗多糖,Sevage法脱去其中的蛋白质,依次通过D101大孔吸附树脂、DEAE-52离子交换色谱及Sephadex G-100凝胶色谱纯化,得到2个天麻多糖(GEP):GEP1-G和GEP2-G,测定其清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基、超氧阴离子自由基和羟基自由基的能力,以评价其抗氧化作用。结果天麻中粗多糖提取率为5.6%,经D101大孔吸附树脂纯化后,粗多糖中多糖含量为65.7%;DEAE-52纯化后,有6个洗脱组分GEP 1~6;组分GEP1和GEP2再经Sephadex G-100纯化得到纯品多糖GEP1-G和GEP2-G,其多糖含量分别是97.3%和98.1%。在抗氧化活性实验中:当GEP1-G和GEP2-G浓度为1 mg·mL^(-1)时,两者对DPPH的清除率分别为44.50%和25.60%,对超氧阴离子抑制率分别为33.32%和21.55%,对羟自由基抑制率分别为39.50%和22.80%。结论通过大孔吸附树脂、离子交换色谱和凝胶过滤色谱得到了纯品天麻多糖,其具有一定的抗氧化作用。     

马齿苋醇提物和当归醇提物的抗氧化活性研究

目的 研究马齿苋醇提物和当归醇提物的体外抗氧化作用,并比较两者合用时的抗氧化能力.方法 在体外化学模拟条件下,采用Fenton反应法和模拟机体中黄嘌呤与黄嘌呤氧化酶反应系统分别测定马齿苋醇提物、当归醇提物及两者合用对羟自由基(OH·)和超氧阴离子自由基(O2-·)的清除能力.结果 马齿苋和当归醇提物及两者合用对O2-·、和OH·均有良好的清除能力,且呈良好的量效关系;两者联合使用对O2-·、和OH·的清除能力明显优于单独使用;当归醇提物中阿魏酸含量与其对O2-·、和OH·清除能力呈正相关,r分别为0.954和0.932.结论 当归醇提物的抗氧化能力强于马齿苋醇提物,并与阿魏酸含量的相关性好,初步确定当归中抗氧化相关活性成分主要为阿魏酸;当归醇提物和马齿苋醇提物合用具有协同作用.     

蒜氨酸、蒜酶及其混合物的体外抗氧化活性研究

研究蒜氨酸、蒜酶及其混合物的体外抗氧化活性.方法建立超氧阴离子自由基(·O2-)和羟基自由基(·OH)产生体系,应用Fe2+引发的卵磷脂过氧化体系,分别采用羟胺法、水杨酸法及硫代巴比妥酸法测定蒜氨酸、蒜酶及其混合物对·O2 -和·OH的清除能力及抗脂质过氧化能力.结果蒜氨酸,蒜酶及其混合物对·O2 -和·OH具有良好的...     

菟丝子提取物清除自由基作用的研究

目的 研究菟丝子提取物的体外抗氧化活性.方法 采用热水提取、酶-Sevage法除蛋白、不同比例乙醇分级沉淀等方法获得菟丝子多糖提取物;经95％乙醇回流提取,2乙酸乙酯、正丁醇萃取,得到乙酸乙酯和正丁醇提取物.利用1,1-二苯基-2-苦苯肼自由基(DPPH·)和超氧阴离子自由基(O2-·)分别测定了各组分的抗氧化活性.结果 菟丝子提取物均具有一定的抗氧化活性,且呈显著的量效关系.菟丝子乙酸乙酯、正丁醇提取物清除自由基的能力大于氧化型谷胱甘肽,小于还原型谷胱甘肽;菟丝子多糖清除自由基的能力均小于氧化型谷胱甘肽,其中90％醇沉多糖清除自由基的能力较强.结论 菟丝子乙酸乙酯、正丁醇提取物以及90％醇沉多糖是天然抗氧化剂的良好来源,可以进一步分离纯化.     

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。     

不同提取方式对金线莲多糖含量及DPPH自由基清除活性的影响

目的考察不同提取方式对金线莲多糖含量、结构及抗氧化活性的影响。方法采用热水回流提取法、超声提取法和酶法分别提取金线莲多糖,苯酚硫酸法测定多糖含量,刚果红实验检测三螺旋结构,采用DPPH自由基清除实验评价其抗氧化活性。结果不同提取方式对多糖的产率和DPPH清除活性均有影响,其中超声提取和酶解提取得到的多糖DPPH自由基清除活性优于热水回流提取所得金线莲多糖;提取所得金线莲多糖不含三螺旋结构。结论综合考虑提取效率、抗氧化活性和工艺成本,超声提取为最优方法。     

新疆两色金鸡菊模拟茶饮自由基清除、胰脂肪酶活性抑制及成分分析

目的：考察新疆两色金鸡菊模拟茶饮水提取物清除自由基、胰脂肪酶活性抑制能力,并对其成分进行HPLC分析。方法：采用去离子纯净水煎煮两色金鸡菊获得模拟茶饮水提取物。对模拟茶饮水提取物进行DPPH、ABTS⁺·、·OH和NO·自由基的清除能力考察;同时考察模拟茶饮水提取物对胰脂肪酶活性抑制能力;使用HPLC法分析模拟茶饮水提取物中的主要物质成分。结果：模拟茶饮水提取物对DPPH自由基的清除能力（SC₅₀）为（228.6±4.61）μg·mL^-1;对ABTS^+·自由基的清除能力（SC₅₀）为（128.4±5.83）μg·mL^-1;对·OH自由基的清除能力（SC₅₀）为（22.41±1.13）μg·mL^-1;对NO·自由基的清除能力（SC₅₀）为（149.8±11.6）μg·mL^-1;对胰脂肪酶活性抑制能力（IC₅₀）为（366.4±8.12）μg·mL^-1。经HPLC成分分析,模拟茶饮水提取物主要含有绿原酸、黄诺马苷、栎草亭-7-O-β-D-吡喃葡萄糖苷、马里苷、异奥卡宁和奥卡宁等成分。结论：新疆两色金鸡菊模拟茶饮水提取物具有一定的自由基清除能力,同时具有一定的抑制胰脂肪酶活性的能力。     

Purification and Structural Characterization of Sulfated Polysaccharide from Sargassum myriocystum and its Efficacy in Scavenging Free Radicals

Sulfated polysaccharides from marine algae are one of the commercially beneficial compounds with a range of pharmaceutical and biomedical applications. They are testified to be effective against free radicals and related health complications. This study aims to determine the antioxidant potential of the sulfated polysaccharide from Sargassum myriocystum, followed by its purification and structural characterization. Amount of extract obtained was 5% from 10 g of plant material. The carbohydrate and sulfate content were found to be 31 and 0.34 mg/10 g of plant material, respectively. Total sulfated polysaccharide extract showed a good radical scavenging activity at lower concentrations. The active principle from the total sulfated polysaccharide was fractionated in anion exchange and gel filtration columns followed by structural characterization using Fourier transform infrared and nuclear magnetic resonance spectroscopy. Fraction 12 closely matched with the Fourier transform infrared and nuclear magnetic resonance spectra of fucoidan. Based on the results obtained, we conclude that sulfated polysaccharide from Sargassum myriocystum is identified as Fucoidan with potential radical scavenging activity compared to butylated hydroxyl toluene.     

贵州产天冬总皂苷清除氧自由基能力的研究

目的 提取贵州产天冬中总皂苷,并观察其清除氧自由基作用. 方法 提取贵州产天冬总皂苷,选用菝葜皂苷元为对照品,采用分光光度法,高氯酸显色,310 nm波长处测定其吸光度,计算天冬中总皂苷的含量;采用连苯三酚法及邻二氮菲-Fe(Ⅱ)/H₂O₂体系,用分光光度法测定天冬总皂苷对O^2-和&#8226;OH的影响. 结果以菝葜皂苷元为对照品,贵州产天冬中天冬总皂苷的含量为2.390%,RSD＝1.19%(含量均以干燥品计算);提取的天冬总皂苷在体外对O^2-具有清除作用(P<0.01),其对O^2-清除率及O2-的抑制率与天冬总皂苷含量成正相关;贵州产天冬中天冬总皂苷对&#8226;OH也有一定的清除作用,清除率为(29.1±0.17)%(P<0.05). 结论 贵州产天冬中天冬总皂苷对O^2-具有显著的清除及抑制作用,对&#8226;OH也有一定的清除作用.     

海绵polymistia spongia提取物aldisin的抗脂质过氧化及清除自由基作用研究

目的研究海绵ｐｏｌｙｍｉｓｔｉａｓｐｏｎｇｉａ提取物ａｌｄｉｓｉｎ的抗脂质过氧化及清除自由基作用。方法采用ＭＤＡ－ＴＢＡ比色法测定组织匀浆中过氧化脂质（ＬＰＯ）含量；采用邻苯三酚自氧化法测定ａｌｄｉｓｉｎ对Ｏ·２自由基的清除作用；采用分光光度法测定ａｌｄｉｓｉｎ对Ｃｕ２＋－ＶｉｔＣ体系产生的·ＯＨ自由基的清除作用；采用ＥＳＲ法测定ａｌｄｉｓｉｎ对ＤＰＰＨ自由基的清除作用。结果ａｌｄｉｓｉｎ具有显著的抗脂质过氧化作用，并能有效地清除Ｏ·２、·ＯＨ和ＤＰＰＨ自由基，在０．４２６μｍｏｌ·Ｌ－１～１８．５ｍｍｏｌ·Ｌ－１浓度范围内有明显的量效关系。结论ａｌｄｉｓｉｎ是自由基清除剂。     

Wheat Seedlings as Food Supplement to Combat Free Radicals: An In Vitro Approach

The present study was designed to evaluate the antioxidant activity of 5 organic solvent extracts (petroleum ether, n-hexane, chloroform, ethyl acetate and methanol) of wheat grains, 3, 5 and 7 days old wheat seedlings. To determine the antioxidant activity of five extracts of four different samples, 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, total phenolic content and ferrous reducing power ability were carried out. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging effect of chloroform and ethyl acetate extracts of 3 days old wheat seedlings was higher than wheat grains. Chloroform, ethyl acetate and methanol extracts of 3 days old wheat seedlings exhibited higher 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging effcet than extracts of other samples. The phenolic content was high in chloroform, ethyl acetate and methanol extract of 5 days old wheat seedlings. When compared with wheat grain, reducing power ability was high in chloroform, ethyl acetate and methanol extract of wheat seedlings, especially in 3 and 5 days old wheat seedlings. From the above results, it was concluded that chloroform, ethyl acetate and methanol extract of 3, 5 and 7 days old wheat seedlings showed better antioxidant activity than the wheat grain extracts. Hence, the results of the present study suggest the intake of wheat seedlings as a food supplement to combat the diseases caused by free radicals.     

Evaluation of antioxidative, protective effect against H2O2 induced cytotoxicity, and cytotoxic activities of three different Quercus species

Quercus species are used as antidiarrheic, for the treatment of hemorrhoid, oral and anal mucosa inflammation. These tree species have been of interest to researchers because of their usage in folk medicine, consumption as food, beverage and especially usage of oak woods for construction in wine barrels. The DPPH, SO and NO radical scavenging activities, protective effect against H2O2 induced cytotoxicity as well as their cytotoxic activity against Hep-2 human larynx epidermoid carcinoma cell line of the MeOH and water extracts of the barks of Quercus cerris var. cerris, Quercusmacranthera subsp. syspirensis and Quercus aucheri were investigated for the first time. Total phenolic content of the extracts was also evaluated by Folin-Ciocalteu method. Results demonstrated that the extracts showed strong radical scavenging activity comparable to those of standard compounds. Extracts also showed good protective effect against H2O2 induced cytotoxicity on human erythrocytes comparing to ascorbic acid. On the other hand, while each extract showed dose dependent cytotoxic activity, MeOH extract of Q.macranthera subsp. syspirensis showed the strongest cytotoxicity against the tested cell line. Taken together, the results showed that Quercus species may be a promising alternative to synthetic substances as natural compound with high antioxidant and antiproliferative activities.     

Extraction of water-soluble polysaccharide and the antioxidant activity from Ginkgo biloba leaves

Water-soluble polysaccharide was isolated from Ginkgo biloba leaves with the method of water-dissolving and ethanol-precipitating. The optimized condition for polysaccharide by orthogonal experiment was water to sample as 30:1 (v/w), at 80°C for 3.5 h. Under the condition the finally dried extract was 9.025%, and the content of polysaccharide was 20.9% in the extract and 1.887% in the leaves. The antioxidant activities of the extract were investigated. The scavenging rates of the present extract on hydroxyl, DPPH, and superoxide radicals were 64.05, 17.62, and 11.8%, at polysaccharide concentrations of 4.18, 8.36, and 4.18 μg/ml, whereas with vitamin C at similar concentrations with polysaccharide, the scavenging rates were 9.15, 5.76, and 5.72%, respectively.     

Antioxidant and Free Radical Scavenging Effects of Lippia nodiflora

This study evaluated the in vitro antioxidant potential of methanol extract of Lippia nodiflora Mich. (Verbenaceae) (MELN). The different antioxidants assays, including total antioxidant activity, reducing power, free radical, superoxide anion radical, hydroxyl radical, hydrogen peroxide, nitric oxide scavenging, and total phenolic content, were studied. MELN exhibited potent total antioxidant activity that increased with increasing amount of extract concentration (50, 100, 200, and 400 μg/mL), which were compared with standard drug α -tocopherol (400 μg/mL). The different concentrations of MELN and α -tocopherol showed inhibition of 49.07%, 58.96%, 63.07%, 68.29%, and 74.59%, respectively, on peroxidation in linoleic acid emulsion. In addition, MELN had effective reducing power, free radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, hydrogen peroxide radical scavenging, and nitric oxide scavenging activity, and total phenolic content depending on concentration. These various antioxidant activities were compared with standard antioxidants such as BHA, BHT, catechin, and α -tocopherol.