杜仲素抗氧化活性研究

以VC 为阳性对照,对杜仲素和高纯绿原酸清除羟自由基(·OH)、超氧阴离子自由基(O2·)及1,1- 二苯基-2- 苦苯肼自由基(DPPH 自由基)活性进行研究,并通过计算清除率比较清除各种自由基活性的效果。结果表明：杜仲素在不同自由基体系中抗氧化活性不同,清除自由基能力为O2·＞ DPPH 自由基>·OH,对3 种自由基的最大清除率依次为95.85%、75.31% 和31.10%。因此,杜仲素具有较强的抗氧化作用。     

花生红衣粗多酚体外抗氧化活性研究

对花生红衣粗多酚抗氧化活性进行研究.采用乙醇、丙酮、蒸馏水3种溶剂提取花生红衣中多酚类物质,通过粗多酚提取液总抗氧化能力(T-AOC)、超氧阴离子自由基(O2-·)清除能力、羟基自由基(·OH)清除作用的测定,比较了3种酚提液的体外抗氧化活性,并测定了其中总多酚含量.结果表明,3种粗多酚提取液总多酚含量分别为9.7％、9.2％、6.3％;在不同抗氧化体系中,3种酚提液均具有良好的抗氧化活性,其中60％乙醇提取液抗氧化能力均高于体积分数0.02％的Vc,抗氧化能力的大小顺序为:60％乙醇提取液＞60％丙酮提取液＞蒸馏水提取液.     

三种来源的石榴多酚抗氧化活性比较

目的:比较研究石榴皮、石榴汁、石榴渣多酚提取物的抗氧化活性。方法:通过测定多酚的总还原力、超氧阴离子自由基清除能力、羟自由基清除能力、DPPH·清除能力和对脂质过氧化的抑制能力五个指标评判和比较三种石榴多酚的体外抗氧化活性。结果:还原能力强弱为石榴渣多酚>石榴皮多酚>石榴汁多酚;对超氧阴离子自由基的清除能力顺序为:石榴渣多酚>石榴汁多酚>石榴皮多酚;清除羟自由基能力大小为:石榴汁多酚>石榴渣多酚>石榴皮多酚;对DPPH自由基的清除能力大小为:石榴汁多酚>石榴渣多酚>石榴皮多酚;对脂质过氧化的抑制能力强弱为:石榴渣多酚>石榴汁多酚>石榴皮多酚。结论:三种石榴多酚均具有较强的体外抗氧化和清除自由基活性,不同的评价体系,反应出的抗氧化能力高低不同。总体来说,石榴渣多酚和石榴汁多酚的抗氧化活性要高于石榴皮多酚,这可能与多酚组成有关。     

香辛料提取物抗氧化活性及其作用模式的研究

采用不同的抗氧化活性测定体系对丁香、迷迭香、桂皮、甘草、肉豆蔻、白豆蔻6 种香辛料提取物抗氧化活性进行研究,并探讨其抗氧化作用模式。首先采用脂质体氧化体系测定香辛料提取物对TBARS 的抑制作用,进一步测定样品的清除DPPH 自由基能力,还原能力(FRAP),及对Cu2+ 和Fe2+ 的螯合能力,同时与商品抗氧化剂BHA 的抗氧化活性进行比较,并通过福林- 酚法测总多酚含量。6 种香辛料醇提物均有较强的抗脂质氧化活性和较高的总多酚含量;其中总多酚含量与TBARS 值呈显著的负相关性(r ＝－ 0.69,P ＜ 0.05),与DPPH 自由基清除能力呈显著相关性(r ＝ 0.84,P ＜ 0.05),说明香辛料醇提物中的总多酚含量越高,其所具有的抗氧化能力越高。DPPH自由基清除能力与还原能力显著相关(r ＝ 0.84,P ＜ 0.05)。TBARS 与DPPH 自由基清除能力和FRAP 值不相关(P ＞0.05),Fe2+ 螯合活力与TBARS、DPPH 自由基清除能力和FRAP 值均不相关(P ＞ 0.05)。香辛料提取物的抗氧化作用与总多酚含量密切相关,其抗氧化性主要是通过清除自由基,螯合金属离子和还原能力来实现的。     

大蒜皮提取物抗氧化活性初步研究

目的:研究大蒜皮乙醇提取物的抗氧化活性。方法:采用超声提取法、索氏提取法、浸提法3种方法提取大蒜皮中的有效成分,采用清除DPPH自由基、羟基自由基(·OH)、超氧阴离子自由基(·O2-)和亚硝酸盐4种体外模型,研究大蒜皮提取物抗氧化活性。结果:3种提取方法得到的大蒜皮提取物对DPPH自由基的清除能力均高于没食子酸;超声法得到的大蒜皮提取物对·O2-的清除能力要强于没食子酸;索氏提取法得到的大蒜皮提取物对·O2-的清除作用和没食子酸几乎相当,但是对·OH和NO2-的清除效果与Vc和没食子酸相比,均有一定的差距;同时发现加热对大蒜皮提取物清除自由基的能力无明显影响。结论:大蒜皮乙醇提取物具有一定的抗氧化活性,并且大蒜皮中所含的抗氧化活性物质具有热稳定性。     

覆盆子不同极性溶剂提取物的抗氧化活性比较

为比较覆盆子不同极性溶剂提取物的抗氧化活性,分别用正丁醇、乙酸乙酯、丙酮、去离子水、50%乙醇和石油醚进行萃取,测定各提取物总多酚和总黄酮的含量,并通过清除DPPH自由基、ABTS自由基、羟基自由基和总还原能力4种体系对其体外抗氧化活性进行评价。结果显示,乙酸乙酯提取物中总多酚含量最高,50%乙醇提取物中总黄酮含量最高;50%乙醇提取物清除DPPH自由基能力和ABTS自由基能力最强,水提取物清除羟基自由基能力最强,丙酮提取物总还原能力最强。结果表明覆盆子不同极性溶剂的提取物均有抗氧化活性,可作为天然抗氧化剂开发。     

山杏种皮提取物体外抗氧化活性研究

目的:研究山杏种皮提取物总多酚含量及其体外抗氧化活性。方法:选用体积分数80%的乙醇为溶剂,采用超声辅助法制备山杏种皮提取物。采用Folin-酚试剂法测定山杏种皮提取物的总多酚含量。采用FRAP法测定山杏种皮提取物的总抗氧化能力。以2,6-二叔丁基对甲酚(BHT)、没食子酸丙酯(PG)为对照样品,分别测定山杏种皮提取物对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、超氧阴离子自由基(O2·軈)、羟自由基(·OH)的清除能力、对β-胡萝卜素/亚油酸体系的抑制能力及其还原力。结果:山杏种皮提取物中总多酚含量为(186.7±15.6)mg/g,其FRAP值为(3.715±0.012)mmol/g;对DPPH·、O2·軈、·OH具有清除作用,清除率分别为80%、97%、98%;对β-胡萝卜素/亚油酸体系具有明显的抑制作用。结论:山杏种皮提取物具有较强的抗氧化能力。     

萌发糙米中多酚物质的抗氧化特性

以抗坏血酸、阿魏酸和2,6-二叔丁基-4-甲基苯酚(BHT)为对照,对萌发糙米中的2种多酚提取物的抗氧化能力进行测定。结果表明:萌发糙米中可溶性和不溶性多酚物质含量分别为(6.03±0.03)、(32.35±0.05)mg/100g;可溶性和不溶性阿魏酸含量分别为(4.82±0.01)、(20.04±0.77)mg/100g;5种试样对O―2的清除率顺序为BHT>阿魏酸>不溶性多酚>可溶性多酚>抗坏血酸;清除OH能力的顺序为抗坏血酸>阿魏酸>BHT>可溶性多酚>不溶性多酚;清除DPPH自由基能力的顺序为不溶性多酚>阿魏酸>BHT>可溶性多酚>抗坏血酸;168h时5个试样抗油脂氧化能力大小顺序为阿魏酸>BHT>可溶性多酚>不溶性多酚>抗坏血酸。因此,萌发糙米中的多酚物质具有一定的抗氧化能力,部分指标优于抗坏血酸和BHT。     

不同溶剂提取对刺梨物质含量变化及抗氧化活性的影响

为探究不同极性的溶剂提取对刺梨物质含量变化及抗氧化活性的影响,分别以水、甲醇、60%乙醇、无水乙醇、正丁醇和乙酸乙酯为提取溶剂,通过测定提取物中抗坏血酸、总多酚、总黄酮、单宁和总三萜含量,采用体外抗氧化方法对刺梨不同溶剂提取物进行抗氧化活性测定,并采用抗氧化活性综合（antioxidant potency composite,APC）指数法进行比较分析。结果表明：60%乙醇提取物中总多酚、总黄酮、单宁和总三萜含量最高;水提取物中抗坏血酸含量最高;乙酸乙酯提取物中总多酚、总黄酮、抗坏血酸和总三萜含量最低;正丁醇提取物中单宁含量最低。对抗氧化活性而言,60%乙醇提取物清除DPPH 自由基与ABTS+自由基能力和还原力最强;甲醇提取物的羟基自由基清除率最高;乙酸乙酯提取物清除超氧阴离子自由基的能力最强。APC 指数显示,6 种溶剂提取物的抗氧化能力由强到弱依次为60%乙醇提取物＞甲醇提取物＞水提取物＞无水乙醇提取物＞乙酸乙酯提取物＞正丁醇提取物。由于不同活性成分之间存在协同或拮抗作用,且不同活性成分在不同溶剂中的溶解性不同,因此不同溶剂提取对刺梨活性物质含量和抗氧化活性影响较大。     

番石榴多酚体外抗氧化活性的研究

微波辅助提取的番石榴多酚粗提物经过NKA-9大孔吸附树脂初步纯化和Sephadex LH-20葡聚糖凝胶的分离,得到四个不同组分(GP1、GP2、GP3、GP4)。以抗坏血酸(V C)为阳性对照,采用总抗氧化能力、羟自由基、超氧阴离子自由基和DPPH自由基四种体外抗氧化能力评价体系测定了番石榴粗多酚(CGP)、大孔吸附树脂纯化多酚(PGP)和各分离组分的抗氧化能力。结果表明:番石榴多酚具有很高的抗氧化活性,总抗氧化能力大小为GP4>V C>GP3>GP2>PGP>CGP>GP1。番石榴多酚能有效地清除羟自由基、超氧阴离子自由基和DPPH自由基,在一定范围内清除自由基能力和浓度成线性关系。     

Free radical scavenging capacity and inhibition of lipid oxidation of wines,grape juices and related polyphenolic constituents

The antioxidant activity of grape juices, wines made from the same lot as juices and their major polyphenolic constituents was measured by the inhibition of lipid oxidation (ferric-thiocyanate) and free radical scavenging (2,2-diphenyl-1-picrylhydrazyl) methods. dl-α-Tocopherol and 3-tertiary-butyl-4-hydroxyanisole (BHA) were used as references. The inhibition of lipid oxidation of the standards followed the order: rutin = ferulic acid > tannic acid = gallic acid = resveratrol > BHA = quercetin > dl-α-tocopherol > caffeic acid. Meanwhile, the free radical scavenging activity of gallic acid was the highest, tannic acid, caffeic acid, quercetin, BHA and rutin activities were intermediate and that for ferulic acid, dl-α-tocopherol and resveratrol were the lowest. Wines had higher activity than the corresponding grape juices and red wine showed the strongest activity among the grape products tested. The antioxidant activity of the samples seems to be based on their free radical scavenging capacity.     

石榴花游离型和结合型多酚提取物抗氧化活性探究

提取石榴花中游离型和结合型多酚粗提物,探究两种多酚提取物的抗氧化能力。采用Folin-Ciocalteu法测定粗提物总酚含量,利用5种体外抗氧化法测定其抗氧化活性。结果显示:游离型多酚粗提物多酚含量显著高于结合型多酚粗提物（P<0.05）;吸收过氧自由基能力（oxygen radical absorbance capacity,ORAC）和清除过氧自由基能力（peroxyl radical scavenging capacity,PSC）测定中,两种多酚粗提物具有与水溶性维E相似的明显荧光动力学特征与剂量依赖趋势,游离型多酚粗提物抗氧化能力强于结合型多酚粗提物（P<0.05）,水溶性维生素E抗氧化能力显著强于两种多酚粗提物（P<0.05）;游离型多酚粗提物DPPH自由基清除能力（DPPH radical scavenging activity,DRSA）、总氧自由基清除能力（trolox equivalent antioxidant capacity,TEAC）和还原力能力（reducing power,RP）均强于结合型多酚粗提物（P<0.05）,但两种多酚粗提物的抗氧化能力均低于阳性对照维生素C（P<0.05）。研究表明:石榴花游离型和结合型多酚粗提物均具有一定抗氧化活性,且游离型抗氧化能力优于结合型,此研究可为天然抗氧化剂的开发和利用提供一定理论依据。     

Antioxidant activity of Sonoran Desert bee pollen

Bee pollen (pollen collected by honey bees) was collected in the high intensity ultraviolet (UV) Sonoran Desert and analyzed by the DPPH (radical 2,2-diphenyl-1-picryhydrazyl) assay and the FRAP (ferric reducing-antioxidant power) assay on six different pollen samples and in eight different water miscible solvents at 50 mg/ml. The bee pollen taxa were characterized for each pollen type by acetylization of the pollen extracts followed by microscopy and comparison with a library of samples native to the Sonoran Desert. The standards (R-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), known as TROLOX, gallic acid and α-tocopherol (vitamin E) were analysed as standards to determine the potency of each pollen sample in the most efficient solvent. The Mimosa pollen sample displayed the highest antioxidant activity. Total polyphenolics, flavanols, flavones were determined, and the results are reported in milligrams of gallic acid, quercetin and naringenin per gram of pollen, respectively. There was good correlation between antioxidant activity and total phenolics. The order of effectiveness of the pollen samples in regard to antioxidant activity was determined and the most effective extraction solvents are discussed. Finally, solid phase micro-extraction, coupled with gas chromatography–mass spectroscopy was utilized to identify and quantify polyphenolic compounds known to have free radical scavenging activity in the pollen samples.     

Antioxidant and antibacterial activities of polyphenolic compounds from bitter cumin (Cuminum nigrum L.)

Cumin is one of the commonly used spices in food preparations. It is also used in traditional ayurvedic medicine as a stimulant, carminative and astringent. Earlier we have reported that bitter cumin (Cuminum nigrum L.) possess the most potent antioxidant activity among cumin varieties—cumin, black cumin and bitter cumin. In this study, we have further characterized the polyphenolic compounds of bitter cumin and also their antioxidant and antibacterial activity using different model systems. The major polyphenolic compounds of cumin seeds were extracted with 70% methanol, 70% acetone, water, separated by HPLC and their structures were elucidated by LC-MS. The profile of phenolic acids/flavonols in bitter cumin were found to be gallic acid, protocatechuic acid, caffeic acid, ellagic acid, ferulic acid, quercetin and kaempferol. The antioxidant activity of the cumin extract was tested on 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging, soybean lipoxygenase-dependent lipid peroxidation, rat liver microsomal lipid peroxidation and superoxide anion (O²⁻) scavenging. The bitter cumin extract exhibited high antioxidant activity with IC₅₀ values of 14.0±0.5 μg, 28.0±3.0 μg, 110±14.0 μg and 125.4±8.7 μg of the extract, respectively for DPPH free radical scavenging, soybean lipoxygenase-dependent lipid peroxidation, rat liver microsomal lipid peroxidation and superoxide anion scavenging. Further, the extract offered a significant protection against DNA damage induced by hydroxyl radicals. Among a spectrum of food-borne pathogenic and spoilage bacteria tested, the cumin extract significantly inhibited the growth of Bacillus subtilis, Bacillus cereus and Staphylococcus aureus. Thus, bitter cumin with an array of polyphenolic compounds possesses potent antioxidant and antibacterial activities.An erratum to this article can be found at     

核桃分心木黄酮物质的组分及其抗氧化性分析

采用超声波辅助乙醇提取核桃分心木黄酮,利用AB-8大孔树脂对黄酮粗提物进行分离纯化,利用自动收集器收集到6 管样液。分别对6 管样品的2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）阳离子自由基、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、羟自由基、超氧阴离子自由基、活性氧（reactive oxygen species,ROS）自由基清除率以及铁离子还原力6 个抗氧化指标进行测定。利用超高效液相色谱-三重四极杆串联质谱仪联用进样,对6 管样品进行组分以及含量分析。结果表明：6 管样品中的ABTS阳离子自由基清除率、羟自由基清除率以及ROS自由基清除率显著高于VC阳性对照。6 管样品中槲皮苷含量最多,质量浓度高达2 426.9 ng/mL,芦丁和没食子酸几乎不存在。组分分析结果除了文献已报道的黄酮类物质柚皮素、金丝桃苷、二氢槲皮素、儿茶素、槲皮苷、芦丁、异槲皮素、没食子酸（属多酚）外,还含有槲皮素、黄芪苷、表儿茶素没食子酸酯。黄酮物质含量与抗氧化能力的相关性分析发现,柚皮素含量与DPPH自由基清除能力和ABTS阳离子自由基清除能力呈显著负相关,而儿茶素含量与ROS清除率呈正相关。验证实验的结果表明：槲皮苷的ABTS阳离子自由基清除能力显著高于VC阳性对照以及混合样品。本研究为槲皮苷、柚皮素和儿茶素的抗氧化能力及其构效关系的研究提供一定理论基础。     

Evaluation of Antioxidant, Radical Scavenging Activity and Polyphenolics Profile in Solanum torvum L. Fruits

Solanum torvum fruit widely used in traditional medicine of India and also in food preparation. Three different extracts such as water (WE), methanol (ME), and ethanol (EE) were used to evaluate their antioxidant and radical scavenging activity by different methods. All the assays results were compared with well-known standard antioxidants. The IC(50) values of assays were determined. The total phenolic and flavonoids content were found to be maximum in water and ethanol extracts, respectively. The electron quenching ability of fruit extract was assayed by DPPH and reducing power assays succeeding order were ME > EE > WE, respectively. Inhibition of membrane damage, was assayed interns of oxidative hemolysis and lipid peroxidation assays, among all WE extract shows 58.00% and 68.55 5% percentage of inhibition with 0.9 and 0.8 correlations (r(2) ), respectively. Antioxidant and radical quenching efficiency were assayed by β-carotene bleaching and hydroxyl radical scavenging method and results were compared with vitamin C and catechin. The in vitro free radical quenching and antioxidant results were well correlated with in vitro DNA protection assay. As analyzed by HPTLC gallic acid content is high in WE (1394 ± 25.0) and ME (598 ± 54.0) whereas ferulic acid is high in EE (32 ± 5.94) μg/g, respectively. This study indicate that S. torvum fruit is an excellent source of natural antioxidant and could be an effective nutritional food supplement, which interns will have therapeutic applications. Practical Application: In siddha medicine on the traditional systems of India the, ripened fruits are used in the preparation of tonic named as a "sundaivattaral choornam" is used to improve the health and prevent several diseases. This study has given an experimental evidence that S. torvum fruit is an excellent source of natural antioxidants.     

Antioxidant and anticancer activities of high pressure-assisted extract of longan (Dimocarpus longan Lour.) fruit pericarp

Longan fruit pericarp was extracted with 50% ethanol employing high pressure (500 MPa) and conventional extraction methods. Total phenolic contents of high pressure-assisted extract of longan (HPEL) and conventional extract of longan (CEL) were 20.8 and 14.6 mg gallic acid equivalents/g dry weight, respectively. Subsequently, the antioxidant activities of these extracts were analyzed employing various antioxidant model systems including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide anion radical scavenging activity, total antioxidant capacity, and lipid peroxidation inhibitory activity. In addition, anticancer activity was also tested using HepG2, A549, and SGC 7901 cancer cell lines. HPEL showed excellent antioxidant and anticancer activities and were higher than CEL. Three phenolic compounds, namely gallic acid, corilagin, and ellagic acid, were identified and quantified by external standard methods. Compared with CEL, HPEL exhibited higher extraction effectiveness in terms of higher extraction yield, higher phenolic content, and higher antioxidant and anticancer activity with shorter extraction time.

Industrial relevance

This study was focused to evaluate the antioxidant and anticancer activity of longan fruit pericarp by high-pressure treatment. The high-pressure treatment provided a better way of utilizing longan fruit pericarp as a readily accessible source of the natural anticancer and antioxidant in food and pharmaceutical industry.     

Effects of Heat Treatment on Total Phenolic Contents,Antioxidant and Anti-Inflammatory Activities of Pleurotus Sajor-Caju Extract

Untreated and heat treated Pleurotus sajor-caju methanolic extracts were examined for total phenolic content, antioxidant and anti-inflammatory activities. Total phenolic content was determined by using the Folin-Ciocalteu method, and results were expressed as mg gallic acid equivalent per g of sample extract. Antioxidant activity was measured by using the DPPH free radical scavenging method while anti-inflammatory activity was measured by using the Griess assay. Methanolic extracts of fresh fruiting bodies were heated at 100 and 121°C for 15 and 30 min. The results showed that total phenolic contents of heat-treated samples did not increase significantly when compared to the control sample. Total phenolic contents were within the range of 0.06 ± 0.05 to 0.08 ± 0.05 mg gallic acid/equivalents g of dry weight. The samples heated at 100°C for 15 and 30 min showed the highest radical scavenging activity at 500 μg/ml with the lowest IC₅₀ values of 10.4 ± 3.11 and 11.67 ± 2.75 μg/ml, respectively. The results suggested that the increased antioxidant activity of P. sajor-caju after the heat treatment might have increased the health beneficial effects to humans.     

Major Polyphenolics in Pineapple Peels and their Antioxidant Interactions

Major polyphenolic compounds in pineapple peels were identified and quantified. The antioxidant capacities of pineapple peel extracts and these polyphenolic compounds were determined using DPPH? scavenging capacity and phosphomolybdenum method. Effects of these polyphenolics’ interactions on their antioxidant capacity were also evaluated. Gallic acid (31.76 mg/100 g dry extracts), catechin (58.51 mg/100 g), epicatechin (50.00 mg/100 g), and ferulic acid (19.50 mg/100 g) were found to be the main polyphenolics in pineapple peels. The IC₅₀ for DPPH? scavenging assay of the extracts was 1.13 mg/ml and total antioxidant capacity was 0.037 g ascorbic acid equivalents/g. The order of DPPH? scavenging capacity of per mole of these polyphenolic compounds present in pineapple peels was gallic acid > epicatechin = catechin > ferulic acid, but it was different when using phosphomolybdenum method the order of which was epicatechin. > catechin > gallic acid = ferulic acid. Results of polyphenolics’ interactions indicated no synergistic effects. In the combinations of ferulic acid-epicatechin and ferulic acid-gallic acid, additive effects were found using both antioxidant activity assays.     

Antioxidant Activities and Polyphenolic Constituents of Bitter Bean Parkia Speciosa

Bitter bean (Parkia speciosa), also known as petai, is a popular non-timber forest product. Traditionally, its fruits are consumed as vegetables and herbal medicines in Malaysia. The present study aimed to evaluate the antioxidant activities of aqueous and ethanol extracts of P. speciosa empty pods using various antioxidant assays, as well as examining their polyphenolic constituent contents. Results showed that with the exception of superoxide radical scavenging activity, ethanol extracts possessed stronger DPPH and ABTS radical scavenging, anti-lipid peroxidation, metal chelating and reducing power activities than aqueous extracts. It was found to contain a higher level of total flavonoids and total phenols than aqueous extracts. The major polyphenolic constituents present in these extracts were gallic acid, catechin, ellagic acid, and quercetin. Although aqueous extracts contained a higher level in gallic acid, its catechin, ellagic acid, and quercetin contents were lower than ethanol extracts. Taken together, the higher amount of polyphenolic compounds present in ethanol extracts could have contributed to its stronger antioxidant activities than aqueous extracts; these results also provided the chemical basis for certain health benefits claimed of P. speciosa empty pods in folk medicine and as foods.