何首乌经乳酸杆菌发酵后抗氧化活性的变化

研究何首乌经过乳酸杆菌发酵后抗氧化活性的变化。用植物乳酸杆菌KCCM12116对何首乌进行发酵处理后，测定其总多酚含量、类黄酮含量、DPPH自由基清除率及降解亚硝酸盐能力等抗氧化活性的变化。结果表明：何首乌经发酵后总多酚和类黄酮含量均有所增加，其中乙醇提取液中的总多酚和类黄酮含量最大，分别为8.25、0.39 g/100 g，水提取物中分别为6.41、0.16 g/hg；何首乌发酵品提取液的DPPH自由基清除率和亚硝酸盐清除率均升高，其中乙醇提取液的DPPH自由基清除率为94.62 %(高于BHT和BHA)，亚硝酸盐清除率在pH为1.2时达到98.2 %。结论：何首乌经乳酸杆菌发酵炮制后抗氧化活性增强，表明此发酵方法是一种值得开发及推广应用的何首乌炮制方法。     

食用菌的抗氧化活性及竹荪抗氧化物质提取工艺的优化

对26种食用菌子实体干品水提液和醇提液分别进行总还原能力、羟自由基、超氧阴离子自由基和DPPH自由基的清除能力测定。结果表明:26种食用菌子实体干品2种提取液均具有不同程度的还原能力及羟自由基、超氧自由基、DPPH自由基清除能力。且总体来说,水提液抗氧化性要强于醇提液抗氧化性。采用模糊综合评价法比较评价26种子实体干品的抗氧化性,其中以竹荪水提液和醇提液的抗氧化活性最高。在单因素实验的基础上,用L9(34)正交设计法,研究乙醇浓度(A)、回流温度(B)、料液比(C)和提取时间(D)等4个因素,以DPPH自由基清除率为评价指标优化长裙竹荪中抗氧化物质的提取条件。结果表明,影响提取物抗氧化效果的主因素为回流温度。最佳的提取工艺为:乙醇浓度90%,回流温度90℃,料液比1/35,回流时间2.5h。     

胡椒叶抗氧化物质提取条件初探

采用系统溶剂提取法处理胡椒叶,确定了胡椒叶的乙醇提取相和水提取相具有较强的DPPH自由基清除能力和较高的多酚含量;通过对胡椒嫩叶、完全稳定叶和老叶的乙醇和水提取液的DPPH自由基清除能力和多酚含量的测量,得出胡椒嫩叶的多酚含量较高,抗氧化活性较高,老叶次之;采用不同浓度的乙醇水溶液常温搅拌浸提胡椒老叶,得出50%左右的乙醇水溶液提取液具有较强的清除自由基能力,较高的多酚含量(5.4 g/100g)和黄酮类化合物含量(0.8 g/100g)。     

桃金娘果实提取物抗氧化活性研究

以去除种子后的桃金娘果实为试验材料,分别采用等体积的水与体积分数80%甲醇进行提取,测定2种提取物的总酚与总黄酮含量,并对2种提取物的DPPH自由基与ABTS自由基清除能力以及总抗氧化能力进行评价。结果表明,桃金娘果实的2种提取物均具有不同程度的多酚含量与抗氧化活性,体积分数80%甲醇提取物的总酚与总黄酮含量、DPPH与ABTS自由基清除能力以及总抗氧化能力均显著高于水提取物。研究结果表明,桃金娘果实多酚物质具有良好的抗氧化活性。     

菜用黄麻叶中总多酚提取及抗氧化活性研究

以菜用黄麻叶为原料,采用冷凝回流法提取黄麻叶中总多酚,通过控制反应温度、反应时间、液料比、乙醇体积分数4个因素来优化黄麻叶中总多酚提取方法,采用响应面法优化黄麻叶总多酚提取工艺。此外,对黄麻提取液进行抗氧化试验。结果表明,各因素对总多酚提取量的影响大小为:液料比反应温度乙醇体积分数反应时间,黄麻叶总多酚最佳提取工艺条件为:反应温度90℃、反应时间2.5 h、液料比30∶1(mL/g)、乙醇体积分数50%,在该条件下黄麻总多酚提取量为13.400 mg/g。此外,黄麻提取液对1,1-二苯基-2-三硝基苯肼(DPPH)、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)和铁离子还原/抗氧化能力(FRAP)均有一定的抗氧化能力。研究结果将为菜用黄麻的药用提供理论依据。     

糖用甜菜抗氧化性研究

实验测定了甜菜水提取液和乙醇提取液对DPPH自由基的清除率,并且采用福林-酚比色法测定了这两种提取液中总酚含量。结果表明,乙醇提取液对自由基的清除率(85.3%)高于甜菜中水提取液(59.5%),并且高于文献报道的甜菜渣的乙醇提取液,这与其中的总酚含量呈现正相关性,说明酚酸是甜菜抗氧化成分。实验表明甜菜具有很好的抗氧化性能,这为甜菜的综合开发提供了重要的理论依据。     

树仔菜中多酚物质的提取工艺及其清除DPPH的抗氧化作用的研究

为研究树仔菜中多酚物质的提取工艺条件并测定其提取物清除DPPH的抗氧化活性,通过单因素试验,分析不同浸提溶剂、料液比、浸提时间、浸提温度对树仔菜多酚提取量的影响,通过正交试验确定树仔菜多酚的最佳提取条件。结果表明：提取剂为蒸馏水,料液比1∶25,提取温度30℃,提取时间8 h。提取条件下,树仔菜平均多酚提取量达到17.45 mg/g;80%甲醇树仔菜提取物对DPPH自由基清除率达到93.66%,明显高于BHT。采用正交试验法优化了树仔菜多酚提取工艺条件,提升了树仔菜多酚提取量,同时树仔菜提取物具有较好的抗氧化作用。     

花生植株类黄酮提取技术优化研究

分别以花生叶片、根系为材料,研究提取剂、料液比、提取时间、提取温度等因素对类黄酮提取效率的影响。结果表明,花生叶片根系干样类黄酮提取的最佳条件是:以70%乙醇作为提取剂,料液比为1∶233,25℃黑暗振荡提取18h,或者70%乙醇,60℃提取1h。花生叶片鲜样类黄酮提取的最佳条件是:以无水乙醇作为提取剂,料液比为1∶40,在25℃黑暗条件下提取18h,或者80℃提取1h。最后过滤提取液,用Al(NO3)3显色法进行类黄酮含量测定。不同花生品种叶片类黄酮含量差异显著,其变异范围为2.97~11.1mg/gDW,正常生长条件下农大818、大白玉、花育20号等品种叶片类黄酮含量较高。     

木奶果果皮多酚提取工艺优化及其体外抗氧化活性研究

研究木奶果果皮多酚水浴振荡辅助提取工艺及其体外抗氧化活性。在单因素试验基础上,采用响应面法优化木奶果果皮多酚的水浴振荡辅助乙醇提取工艺,并以V_C为对照,对DPPH自由基、ABTS自由基和超氧阴离子自由基清除能力进行探讨。结果表明:采用优化后的工艺条件,提取时间63 min、提取温度65℃、乙醇浓度66%、液料比42∶1(m L/g),木奶果果皮多酚提取量为31.2 mg/g,与模型预测值31.0 mg/g相近,最佳工艺实用性强。体外抗氧化活性实验表明,木奶果果皮多酚对于DPPH自由基、ABTS自由基和超氧阴离子自由基的IC50值分别为12.3、2.35、0.141 mg/m L,最高清除率分别为90.6%、99.1%和61.9%,说明木奶果果皮多酚具有很强的抗氧化活性。     

千层金叶片醇提物抗氧化活性的研究

为了探究千层金叶片醇提物的抗氧化活性,本文研究了千层金叶片醇提物及其不同极性部位的抗氧化活性和总多酚含量。研究结果表明：千层金叶片醇提物正丁醇相的总多酚含量最高,为(453.75±0.75) mg/g;75%甲醇粗提物及其正丁醇相对ABTS ⁺自由基的清除能力较抗坏血酸（VC）强;各组分还原力强弱顺序为VC>正丁醇相>75%甲醇粗提物>水相>乙酸乙酯相>BHT>石油醚相;正丁醇相和乙酸乙酯相对DPPH自由基的清除能力较醇提物和水相强,石油醚相最弱;千层金叶片醇提物及其不同极性部位清除ABTS ⁺自由基清除能力、DPPH自由基清除能力及还原力均与其总多酚含量呈正相关。除石油醚相外,千层金叶片醇提物及其不同极性部位均有较强的抗氧化活性,可作为一种良好天然抗氧化剂的物质来源。     

苦丁茶提取物多酚含量与抗氧化活性的测定

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。     

海南白沙绿茶的抗氧化活性及其酚酸类组成的HPLC-MS分析

采用DPPH体系、ABTS体系和Oyaizu法对白沙绿茶的甲醇提取物、70%乙醇提取物和水提取物的抗氧化活性进行测定,并利用HPLC-MS对活性较高的乙醇提取物的抗氧化特征性成分进行分析。结果表明:白沙绿茶3种提取物均具有一定的抗氧化能力,呈浓度效应关系。其中3种提取物中以70%乙醇提取物对DPPH和ABTS清除能力最强,而还原力则弱于水提取物和甲醇提取物。通过HPLC-MS从70%乙醇提取物中得到24个酚类物质,其中15个酚类物质被鉴定为新绿原酸、花旗松素-3-O-芸香糖苷、绿原酸、隐绿原酸、去甲氧基姜黄素、表儿茶素、山奈酚-3-O-芸香糖苷、花旗松素-3-O-葡萄糖苷、槲皮素-双己糖苷、Di-O-咖啡酰奎宁酸、槲皮素、山奈素-3-O-戊糖苷、牛蒡子苷、杨梅素和山奈素。     

In vitro antioxidant activity of ragweed (Ambrosia artemisiifolia L., Asteraceae) herb

The antioxidant activity in 70% aqueous acetone extracts of the herb of Ambrosia artemisiifolia L., Asteraceae was evaluated with regards to total polyphenol and flavonoid contents. Antioxidant activity has been assessed by two commonly used in vitro tests, based on determination of ferric-reducing antioxidant power (FRAP assay) and DPPH free radical scavenging ability (DPPH assay), against butylated hydroxytoluene (BHT), ascorbic acid and quercetin, which were used as positive control substances. The results of both antioxidant tests showed that the plant material expressed a considerable activity (DPPH IC₅₀ = 27.6 μg/ml; FRAP value = 2.37 mmol Fe²⁺/g), attributed to both flavonoid aglyca and resembling glycosides, as verified by dot-blot TLC analysis.     

云南普洱茶不同溶剂提取物抗氧化活性研究

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.     

Free radical scavenging activity of selected medicinal plants of Eastern Botswana

Water and methanol extracts from roots of Ozoroa paniculosa (Anarcardiaceae); seeds of Colophospermum mopane (Caesalpiniaceae) and Cucumis metuliferus (Cucurbitaceae) ripe fruits were assessed for in vitro antioxidant activity. Free radical scavenging activity was measured spectrophotometrically as maximum fading power of DPPH at 525 nm. Water and methanol extracts of Ozoroa paniculosa exhibited higher scavenging potency than extracts of either Colophospermum mopane or Cucumis metuliferus at all tested concentrations. None of the extracts from Cucumis metuliferus exhibited any recognizable free radical scavenging activity. Above 50 microg mL(-1) both water and methanol extracts of Ozoroa paniculosa exhibited 91% scavenging activity similar to the control compounds L-ascorbic acid (91%) and (-) epicatechin (92%). Between 50-100 microg mL(-1), water and methanol extracts of Colophospermum mopane exhibited scavenging potency of < or = 70%. However, above 100 microg mL(-1), both water and methanolic extracts of C. mopane exhibited scavenging activity > 70%. Chloroform extracts of all the tested plants showed poor scavenging activity (< 30%). The order of scavenging potency for the tested samples was as follows: L-ascorbic acid > or = epicatechin > O. paniculosa (methanolic extract) > O. paniculosa (water extract) > O. paniculosa (ethylacetate extract) > C. mopane (methanolic extract) > C. mopane (water extract) > all extracts of C. metuliferus. These findings lend credence to the use of these plants as anti-inflammatory and antioxidant agents in folk medicine.     

Inhibitory Potential of Acroptilon repens against Key Enzymes involved in Alzheimer and Diabetes,Phytochemical Profile,Radical Scavenging,and Antibacterial Activity

Background:This study was devoted to assessing the inhibitory potential of acetone, methanol, and ethanol extracts of Acroptilon repens against disease-associated enzymes, as well as their antioxidant/antibacterial activity and phytochemical composition. Methods:Comparative assessment using various antioxidant evaluation methods, including FRAP, scavenging ability on DPPH radical and hydrogen peroxide, and RP, indicated that the acetone extract presented the highest antioxidant activity, due to its highest total antioxidant content. Results:The TPC and TFC of these extracts were 3.44 ± 0.32 mg GAE/g DW and 2.09 ± 0.2 mg QE/g DW, respectively. The hydrodistillation essential oil from A. repens was analyzed by GC/MS, and 17 compounds were identified. All extracts showed good inhibitory activities against disease-related enzyme acetylcholinesterase and α-amylase, with the lowest IC₅₀ for acetonic extract. Extracts of A. repens exhibited inhibiting activities against the Gram-positive bacteria, with the most effect of acetone extract. Conclusion:Our findings suggest A. repens as a promising source of natural antioxidant, antimicrobial, anti-cholinesterase and anti-amylase agents for the management of oxidative damage, and pharmaceutical, food, and cosmeceutical purposes. Key Words: Acroptilon repens, Antioxidants, Phytochemicals     

大豆豆渣粗提物清除DPPH自由基活性及其协同效应的研究

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。     

Assessment of dermal wound healing and in vitro antioxidant properties of Avena sativa L.

Avena sativa L. (Poaceae) has been reported to have traditional utilization against skin diseases and inflammation. Therefore, in this study, the n-hexane, ethyl acetate, ethanol, and water extracts of A. sativa were investigated for their wound healing and antioxidant activities. Total phenol and flavonoid contents of the extracts were established spectrophotometrically. For the wound healing activity, linear incision and circular excision models on rats and mice were evaluated with a standard ointment Madecassol^®. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Significant wound healing activity was observed with the ointment formulation of the ethanol extract at 1% concentration. The histopathological examination results also supported the outcome of both linear incision and circular excision wound models. All of the extracts exerted low antioxidant activity in the applied assays. The present study provides a scientific evidence for the traditional usage of A. sativa in the management of wound healing.