共查询到18条相似文献,搜索用时 171 毫秒
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以芦丁与Vc为对照,测定云南普洱茶不同溶剂提取物清除DPPH自由基、羟自由基、超氧阴离子自由基、亚硝酸盐的能力及其还原力.结果表明:普洱茶不同溶剂提取物的抗氧化活性与其浓度成正相关,对DPPH自由基、羟自由基与超氧阴离子有较强的清除作用,对亚硝酸盐的清除作用不明显,具有一定的还原力.其中,乙醇沉析物、正丁醇提取物、乙醇提取物、乙醇溶解物对DPPH.自由基清除效果较好,相同浓度下优于芦丁;水提取物、乙醇沉析物及乙酸乙酯提取物对羟自由基清除效果较好,但效果不如Vc;乙酸乙酯提取物对超氧阴离子自由基和亚硝酸盐的清除作用较好,还原力也很强. 相似文献
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菠萝果实的抗氧化性研究 总被引:1,自引:0,他引:1
测定菠萝果肉不同提取剂的提取物对DPPH自由基清除能力及抑制鱼油氧化等抗氧化活性指标.结果表明,丙酮提取剂提取的菠萝果肉提取物清除DPPH自由基的能力最强,为40.72%,接下来依次为甲醇、正己烷、乙酸乙酯提取剂提取的菠萝果肉提取物;用2 mL蒸馏水洗脱物在洗脱吸附C18柱水提取物后表现清除DPPH自由基的能力最强,为53.69%:而且发现菠萝汁:鱼油(体积:质量)的比例为1∶5混合时,菠萝汁对鱼油中脂肪酸氧化的抑制效果最好,表明菠萝果肉具有较强的抗氧化活性,具有一定的开发前景. 相似文献
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利用气相色谱-质谱联用技术(GC-MS),对苦丁茶超声辅助不同有机溶剂(乙醇、乙酸乙酯、石油醚)提取物及超临界CO2萃取物的体外抗氧化活性(DPPH自由基清除能力、羟基自由基清除活性、超氧阴离子自由基清除活性和ABTS +自由基清除能力)进行比较分析。结果表明,苦丁茶不同提取物DPPH清除能力和超氧阴离子自由基清除活性依次为:超声-乙醇提取物>超临界CO2萃取物>超声-乙酸乙酯提取物>超声-石油醚提取物,羟基自由基和ABTS +自由基清除能力依次为:超声-乙醇提取物>超声-乙酸乙酯提取物>超临界CO2萃取物>超声-石油醚提取物。GC-MS结果显示,苦丁茶不同提取物中主要有5类物质,共有49种化学成分,7种共有成分。 相似文献
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苦丁茶提取物多酚含量与抗氧化活性的测定 总被引:4,自引:1,他引:4
首先用不同的有机溶剂分部萃取苦丁茶(Ilex kudincha C.J.Tseng)热水提取物(粗提物),得到氯仿萃取物、乙酸乙酯萃取物、正丁醇萃取物及萃取剩余物,然后采用Folin-Ciocalteu比色法测定粗提物和各萃取物的多酚含量,同时应用DPPH法、TEAC法和FRAP法分别测定粗提物和各萃取物的自由基清除能力和还原Fe3+能力。结果表明,苦丁茶提取物具有较高的多酚含量和较强的抗氧化能力;DPPH法和FRAP法测定各提取物抗氧化能力的结果为乙酸乙酯萃取物>正丁醇萃取物>粗提物>萃取剩余物>氯仿萃取物,TEAC法测定结果为乙酸乙酯萃取物>正丁醇萃取物>粗提物>氯仿萃取物>萃取剩余物;多酚含量与抗氧化能力之间、所用抗氧化测定方法之间均存在较好的相关性。 相似文献
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槟榔花提取物对羟基自由基诱导脱氧核糖降解的保护作用 总被引:1,自引:0,他引:1
以槟榔花茶为试验材料,分别采用3种提取方法,即:①100℃沸水浴提取3次,每次30min;②超纯水常温提取3次,每次6h;③95%的乙醇常温提取3次,每次6h。研究采用不同提取方法对应所得的槟榔花提取物对Fe2+的络合能力、Fe3+的还原能力和DPPH自由基的清除作用;并测定每种提取物的总酚含量,以Fenton反应为模型,研究不同提取物对羟基自由基诱导2-脱氧核糖降解的保护机理。结果表明,以第1种提取方法(100℃沸水浴提取3次,每次30min)所得的提取物抑制脱氧核糖降解和清除DPPH自由基的能力较强,总酚含量较高,但其对Fe2+的络合能力和Fe3+的还原能力相对较弱。 相似文献
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目的对辽东丁香枝的总提液、氯仿层、乙酸乙酯层、正丁醇层、水层进行抗氧化活性的评定。方法采用清除DPPH自由基、清除ABTS+.自由基、还原性和总酚含量测定的方法,利用分光光度法测定辽东丁香枝不同部位在不同浓度下的抗氧化能力及总酚含量。结果辽东丁香枝不同部位具有明显的清除DPPH、ABTS+.自由基的能力,且有较好的还原能力和较高的总酚含量。在清除DPPH自由基体系中,乙酸乙酯层的抗氧化能力最强,其IC50值最低为0.033mg/m L,正丁醇层和氯仿层的次之,IC50分别为0.0546,0.0638mg/m L,在清除ABTS+自由基体系中,各部位抗氧化活性大小为:乙酸乙酯层总提液氯仿层正丁醇层水层;还原性体系测定中,乙酸乙酯层的还原能力接近于BHT的;乙酸乙酯层的总酚含量最大,为164.7μg/mg,接近BHT的168.2μg/mg。结论辽东丁香枝具有较好的抗氧化活性,其抗氧化能力与总酚含量有较好的相关性,需要进一步深入研究,开发为天然抗氧化剂。 相似文献
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诺丽果汁的抗氧化性研究 总被引:2,自引:0,他引:2
采用分光光度计法,以维他命C(Vc)为对照,考察诺丽果汁的多酚含量及其对1, 1-二苯基-2-三硝基苯肼(DPPH)自由基、2,2-联氮双(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基、羟自由基和过氧化氢(H2O2)等的抗氧化活性。结果表明:诺丽果汁中多酚含量较高(1.934 mg/mL),对DPPH自由基、ABTS自由基、羟自由基和过氧化氢等均具有很好的清除活性,且在清除羟自由基能力试验中,其活性显著高于阳性对照(Vc),表明诺丽果汁对人体具有良好的营养保健功效。 相似文献
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大豆豆渣粗提物清除DPPH自由基活性及其协同效应的研究 总被引:3,自引:0,他引:3
用二苯代苦味肼基自由基(DPPH)-TLC法和酶标仪法对大豆豆渣石油醚、乙酸乙酯、丙酮、乙醇粗提物的自由基清除活性进行了定性和定量分析,考察了抗氧化剂维生素C、柠檬酸对大豆豆渣乙醇粗提物清除DPPH自由基活性的协同效应。结果表明:大豆豆渣不同极性粗提物均有一定的自由基清除活性,其中乙醇粗提物的自由基清除活性最强,在浓度为10.0 mg.mL-1,于37℃下保温15 min时,对0.4 mg.mL-1的DPPH自由基的清除率可达76.48%;维生素C和柠檬酸对大豆豆渣乙醇粗提物均能产生一定的协同效应,且维生素C的协同作用强于柠檬酸。 相似文献
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Antioxidant Activities of Hydrolysates of Arca Subcrenata Prepared with Three Proteases 总被引:1,自引:0,他引:1
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In order to get products with antioxidant activity from Arca subcrenata Lischke, the optimal hydrolase and hydrolysis conditions were investigated in the paper. Three proteases (neutrase, alcalase and papain) were applied to hydrolyze the homogenate of A. subcrenata. An orthogonal design was used to optimize hydrolysis conditions, and the pH-stat methods was used to determine the degree of hydrolysis. Viewed from the angle of reducing power, such as scavenging activities against α,α-diphenyl-β-picrylhydrazyl (DPPH) radical and hydrogen peroxide, the antioxidant activities of the alcalase hydrolysate (AH) were superior to neutrase hydrolysate (NH) and papain hydrolysate (PH), and its EC50 values in DPPH radical and hydrogen peroxide scavenging effect were 6.23 mg/ml and 19.09 mg/ml, respectively. Moreover, compared with products hydrolyzed by neutrase and papain, the molecular mass of AH was lower and its content of amino acid of peptides was higher. Therefore, alcalase was selected as the optimal enzyme to produce active ingredients since its hydrolysate exhibited the best antioxidant activity among them and possessed large amount of potential active peptides. 相似文献
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Tea is a popular beverage whose consumption is associated with prevention of certain disorders. The objective of the study
was to investigate the potential neuroprotective effect of white tea extract (WTE) on hydrogen peroxide induced toxicity in
PC12 cells. Cells were treated with various doses of WTE (10–250 μg/ml) before exposition to 250 μM hydrogen peroxide and
cell survival was determined through the MTT and LDH assays. Oxidative stress was quantified in the cells after treatments
as intracellular reactive oxygen species (ROS) production and the antioxidant activity of the extract was assessed in a cell
free system in terms of free radical scavenging capacity. Results showed that WTE has a significant protective effect in the
PC12 cell line against hydrogen peroxide as cell survival was significantly superior in WTE-treated cells compared to hydrogen
peroxide-treated cells. A reduction on intracellular oxidative stress as well as radical scavenging properties were produced
by WTE. Results suggest that WTE protects PC12 cells against H2O2-induced toxicity, and that an antioxidant mechanism through ROS scavenging may be in part responsible for cells neuroprotection. 相似文献
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本研究以前期制备的澳洲坚果蛋白为原料,经复合酶(木瓜蛋白酶和中性蛋白酶)酶解制备澳洲坚果蛋白肽,采用水解度为指标,利用单因素试验与正交试验考察各酶解因素对澳洲坚果蛋白水解度的影响,同时通过不同分子量(3、10、30 kDa)的超滤离心管对制备的蛋白肽进行初步的分离,并基于DPPH自由基清除能力对不同分子量的澳洲坚果蛋白肽的抗氧化活性进行评价。结果表明:各酶解因素对复合酶酶解制备澳洲坚果蛋白水解度的影响依次为酶解初始pH>复合酶配比>酶添加量>酶解时间;最佳复合酶酶解条件为复合酶配比1∶5、酶添加量12 000 U/g、酶解液初始pH 9.0、酶解时间360 min,在此条件下澳洲坚果蛋白的水解度为21.88%;同时,通过分析不同分子量的澳洲坚果蛋白肽组分发现,不同分子量的澳洲坚果蛋白肽均具有抗氧化活性,分子量在3~10 kDa的肽段组分具有较强的抗氧化能力,其DPPH自由基清除能力达到80.97%,且随着蛋白肽组分浓度的增加,其抗氧化能力也逐渐增强。 相似文献
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In this research, some herbal teas and infusions traditionally used in the treatment of diabetes in Turkey, have been studied
for their antidiabetic effects on in vitro glucose diffusion and phenolic contents and antioxidant activities. Ten aqueous herbal tea extracts were examined using an
in vitro method to determine their effects on glucose movement across the gastrointestinal tract. Total phenol content of herbal teas
was analyzed by Folin–Ciocalteu’s procedure. Antioxidant activities of herbal teas were evaluated by the effect of extracts
on DPPH radical and hydrogen peroxide scavenging. Antioxidant activity was defined as the amount of the sample to decrease
the initial DPPH· concentration by 50% as efficient concentration, EC50. Antiradical activity [AE] was calculated as 1/EC50. Values were evaluated statistically. Results support the view that none of the herbal teas showed antidiabetic effect on
glucose diffusion using in vitro model glucose absorption. Teas were arranged in the order of green tea > peppermint > thyme > black tea > relax tea > absinthium
> shrubby blackberry > sage > roselle > olive leaves according to their total phenol contents. Among ten herbal teas, green
tea had the highest hydrogen-donating capacity against to DPPH radical. Ranking of the herbal teas with respect to their DPPH
radical scavenging activity were green tea > peppermint > black tea > thyme > relax tea > absinthium > roselle > olive leaves
> sage > shrubby blackberry. It was determined that adding flavoring substances such as lemon, bergamot, clove and cinnamon,
which are commonly used in preparation of black tea in Turkey resulted to have synergistic effect on total antioxidant activities
of black and peppermint teas. The highest hydrogen peroxide inhibition value (65.50%) was obtained for green tea at a 250 μl/ml
concentration. The H2O2 scavenging activity of herbal teas decreased in the order green tea > peppermint > relax tea > black tea > thyme > olive
leaves > sage > absinthium > shrubby blackberry > roselle. In particular, their phenolic compounds and antioxidant activities
may be useful for meal planning in type 2 diabetes. They could contribute to sustain plasma antioxidant level because antioxidants
present in plants and herbs prevent the development of vascular diseases seen in type 2 diabetes. 相似文献
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Syed Sultan Beevi Mangamoori Lakshmi Narasu Bandi Boje Gowda 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(1):8-17
Aerial parts (leaves and stem) of Raphanus sativus, which are usually discarded were found to possess potent antioxidant and radical scavenging activity, as measured by standard
antioxidant assays. Methanolic and acetone extracts of R. sativus leaves had total polyphenolic content of 86.16 and 78.77 mg/g dry extract, which were comparable to the traditional rich
sources such as green tea and black tea. HPLC identification of polyphenolics indicated the presence of catechin, protocatechuic
acid, syringic acid, vanillic acid, ferulic acid, sinapic acid, o-coumaric acid, myricetin, and quercetin in leaves and stem. Among the different extraction solvents, methanolic extract of
leaves and stem showed potent reductive capacity, significantly inhibited linoleic acid peroxidation and displayed metal chelating
activity. Further, they scavenged free radicals effectively with IC50 (half maximal inhibitory concentration) of 31 and 42 μg/ml for DPPH radical, 23 and 52 μg/ml for superoxide radical, 67 and
197 μg/ml for hydrogen peroxide, and 56 and 62 μg/ml for nitric oxide, respectively. Leaves showed most potent antioxidant
and radical scavenging activity as compared to stem, which may be accounted for the high polyphenolic content. Leaves and
stem of R. sativus, often under-utilized part of this vegetable, thus possessed considerable amount of polyphenolics. Hence, it should be regarded
as a potential source of natural antioxidants and could be effectively employed as an ingredient in health or in functional
food. 相似文献