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1.
  总被引:1,自引:0,他引:1  
ABSTRACT: Four bean varieties ( Phaseolus vulgaris L.) (white kidney, red pinto, Swedish brown, and black kidney) and their hull fractions were extracted with 80% acetone and evaluated for their phenolic contents and antiradical activities. Total phenolic content of bean hulls and whole seed extracts ranged from 6.7 to 270 and 4.9 to 93.6 mg/g extract as catechin equivalents, respectively. Trolox equivalent antioxidant capacity (TEAC) assay revealed that the antioxidant capacity of red, brown, and black whole seed extracts was in the same order of magnitude with little variation. TEAC values of red and brown whole seed extracts were superior to that of black whole seed extract. On the basis of the total phenolic content and TEAC values, it can be deduced that colored beans possess superior antioxidative activity compared with white beans. The hydrogen peroxide scavenging capacity of different bean extracts ranged from 58% to 67% at 50 ppm and 65% to 76% at 100 ppm. The corresponding superoxide radical scavenging capacity was 24% to 29% at 50 ppm and 53% to 60% at 100 ppm. The 2,2–diphenyl-1–picrylhydrazyl (DPPH) radical scavenging capacity of black bean whole seed extracts was 22% at 50 ppm, whereas the other extracts showed 100% scavenging of this radical at both 50 and 100 ppm levels. The hydroxyl radical scavenging capacities of the bean extracts at 50 and 100 ppm were 12% to 29% and 32% to 49%, respectively. All extracts used prevented human low-density lipoprotein (LDL) cholesterol oxidation by 61.4% to 99.9% at 2 to 50 ppm level as catechin equivalents.  相似文献   

2.
    
In the present study, the aerial parts of Achyranthes ferruginea underwent investigation of their in vitro antioxidant and free radical-scavenging activities in cell-free conditions, their phytoconstituents using gas chromatography-mass spectrometry (GC-MS), and their cytotoxic activity in HeLa cells. A. ferruginea was extracted with 80% methanol and successively fractionated with solvents to yield petroleum ether (PEF), chloroform (CHF), ethyl acetate (EAF), and aqueous (AQF) fractions. GC-MS analysis revealed that CHF contained ten phytoconstituents, including different forms of octadecanoic acid methyl esters. The total antioxidant and ferric-reducing antioxidant capacities of the extracts and the standard catechin (CA) were as follows: CA >CHF >PEF >CME (crude methanolic extract) >EAF >AQF, and CA >CHF >EAF >PEF >AQF >CME, respectively. CHF showed the highest DPPH-free radical-scavenging activity, with a median inhibitory concentration of 10.5 ± 0.28 µg/ml, which was slightly higher than that of the standard butylated hydroxytoluene (12.0 ± 0.09 µg/ml). In the hydroxyl radical-scavenging assay, CHF showed identical scavenging activity (9.25 ± 0.73 µg/ml) when compared to CA (10.50 ± 1.06 µg/ml). Moreover, CHF showed strong cytotoxic activity (19.95 ± 1.18 µg/ml) in HeLa cells, which was alike to that of the standards vincristine sulfate and 5-fluorouracil (15.84 ± 1.64 µg/ml and 12.59 ± 1.75 µg/ml, respectively). The in silico study revealed that identified compounds were significantly linked to the targets of various cancer cells and oxidative enzymes. However, online prediction by SwissADME, admetSAR, and PASS showed that it has drug-like, nontoxic, and potential pharmacological actions.  相似文献   

3.
  总被引:1,自引:0,他引:1  
Tea (Camellia sinensis) is the most highly consumed beverage in the world next to water. The common way of preparation is steeping in hot water which is varying for different type of tea. We investigated the antioxidant properties of 6 type of tea leaves under different time and temperatures of extraction method used. In general, all samples tested in this study demonstrated high levels of antioxidant capacity and antioxidant activity. The results indicate that the antioxidants activity is significantly affected by time and temperature of steeping and the highest was depending on the variety. White state values, green and black teas showed different levels of antioxidants under different extraction conditions. Overall, the highest activity for white tea was in prolonged hot and in some assays prolonged hot and cold extracts, whereas for green tea the highest activity observed in prolonged cold steeping while, for black tea was in short hot water infusion. The results of this study showed the antioxidant capacity of white and green tea was greater than black tea.  相似文献   

4.
    
Volatile constituents of beechwood creosote were determined using gas chromatography (GC) and gas chromatography–mass spectrometry (GC‐MS). The major volatile constituents of creosote were 2‐methoxyphenol (guaiacol; 25.2%) 2‐methoxy‐4‐methylphenol (4‐methylguaiacol; 21.4%), 3‐methylphenol (m‐cresol; 8.3%) 4‐methylphenol (p‐cresol; 7.9%) 2‐methylphenol (o‐cresol; 4.6%) and phenol (2.8%). The antioxidant activity of creosote was evaluated by three different chemical assays. Beechwood creosote exhibited potent inhibitory effects on the formation of conjugated diene hydroperoxides (from methyl linoleate) at concentrations of 500, 750 and 1000 µg ml?1. Creosote had a potent inhibitory effect on the oxidation of hexanal for 40 days at a level of 5 µg ml?1 and also inhibited malonaldehyde (MA) formation from ethyl arachidonate by 92% at a level of 50 µg ml?1. The antioxidative activity of creosote was comparable with that of the well‐known antioxidants α‐tocopherol and BHT in the hexanal assay. However, creosote displayed comparatively lower antioxidant activity in the other two assays. Copyright © 2005 Society of Chemical Industry  相似文献   

5.
金钱草清除自由基活性及其成分研究   总被引:3,自引:0,他引:3  
黄海兰  徐波  段春生 《食品科学》2006,27(10):183-188
用2:1的甲醇:氯仿超声提取金钱草成分,并用石油醚、乙酸乙酯和正丁醇依次进行萃取,利用DPPH法、邻二氮菲-Fe2+氧化法和AP-TEMED法进行清除自由基活性实验,同时与合成抗氧化剂BHT进行对照。结果显示乙酸乙酯提取物(EAF)具有最高的清除自由基活性,大于人工合成抗氧化剂BHT。利用硅胶,RP-18和SephadexLH-20对其进行活性追踪分离,得到3种纯的清除自由基活性成分。利用1D、2DNMR和ESI-MS对其结构进行鉴定。结果显示为槲皮素、槲皮素-3-o-葡萄糖甙和山奈酚-3-o-葡萄糖甙。活性大小顺序为槲皮素>槲皮素-3-o-葡萄糖甙>山奈酚-3-o-葡萄糖甙>EAF>BHT。含酚羟基化合物的清除自由基活性与其结构密切相关。活性大小主要取决于酚羟基的数目。  相似文献   

6.
7.
We investigated the effect of roasting degree on volatile and phenolic compounds of coffee beans (Coffea Arabica L. cv. Catimor). The colour, 1,1‐diphenyl‐2‐picrylhydrazyl radical‐scavenging activity and phenolic acids of the aqueous extracts were studied. For the colour, L and b values were increased with an increase in roasting degree. Increasing roasting degrees led to a decrease in radical‐scavenging activity. Maximum radical‐scavenging activity was observed for the light‐roasted coffee. Chlorogenic acid was the most predominant amongst the ten phenolic acids identified, in green and all roasted beans. Syringic acid, p‐coumaric acid, gallic acid and sinapic acid increased with an increase in roasting degree. The volatile compounds were analysed using gas chromatography and mass spectroscopy. Aldehyde was the major volatile compound in green coffee. Our study has demonstrated that light‐roasted coffee gave the most desirable quality of roasted coffee with respect to phenolic content and radical‐scavenging activities.  相似文献   

8.
为进一步探索桉叶提取物抗氧化活性的物质基础,本文采用反相硅胶和制备液相等方法对桉叶提取物中高醇组分进行分离纯化得到4个化合物。接着应用~1H-NMR和~(13)C-NMR光谱分析鉴定化合物的结构,最终鉴定出3个化合物,分别为金丝桃苷、番石榴苷和槲皮素-3-O-α-吡喃阿拉伯糖-2\"-棓酸盐。最后采用DPPH·、ABTS+·和ORAC三种体外检测体系进行抗氧化活性的研究。在DPPH·和ORAC方法中,番石榴苷的抗氧化能力最强,槲皮素-3-O-α-吡喃阿拉伯糖-2\"-棓酸盐的抗氧化能力最低。在ABTS·+方法中金丝桃苷的抗氧化能力最强,番石榴苷的抗氧化能力最低。但与抗氧化剂Trolox相比,三者都表现出更强的抗氧化能力,是有较好发展前景的天然抗氧化剂。本文为桉叶资源的综合开发提供理论指导作用。  相似文献   

9.
对款冬花和决明子中挥发性成分和抗氧化活性进行研究。采用水蒸气蒸馏法提取得到挥发性成分,利用GC-MS对其成分进行分析。用可见分光光度法测定挥发性成分对1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力、ABTS自由基的清除能力以及FRAP能力。结果表明,款冬花和决明子中的挥发性成分对羟基自由基具有不同的清除能力,且不同中药挥发性成分中高含量的总多酚和总黄酮可能是其抗氧化活性的主要物质来源。中药挥发性成分具有较好的抗氧化效果,能够作为天然抗氧化剂应用于食品和烟草工业。  相似文献   

10.
国外天然酚类抗氧化剂的研究进展   总被引:1,自引:0,他引:1  
简述了国外天然酚类抗氧化剂最新研究概况,主要介绍一些当前研究得比较多的、具有较强抗氧化活性的天然提取物,以及天然提取物的各种抗氧化活性试验。  相似文献   

11.
    
Abstract: The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) radical‐scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51– 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27– 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97– 363.38 ± 10.57 μM Fe[II]/kg), and high IC50 of DPPH radical‐scavenging activities (5.24 ± 0.40– 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans‐cinnamic, p‐coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical‐scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical‐scavenging activities.  相似文献   

12.
天然桑椹红色素体外清除自由基活性的研究   总被引:11,自引:0,他引:11  
采用超氧阴离了自由基体系、羟基自由基体系、过氧化氢自由基体系、烷基自由基引发的亚油酸氧化体系及DPPH(二苯代苦味酰肼自由基)自由基体系对桑椹红色素的清除自由基活性进行了研究,并同VC进行了比较。结果表明,桑椹红色素对这几种自由基均有不同程度的清除作用,其对超氧阴离子自由基、羟基自由基和过氧化氢自由基的清除能力较好,且高于VC。清除DPPH自由基的能力低于VC。在所选浓度范围内,清除烷苯自由基的能力小明显,和VC相当,清除率均低于50%。桑椹红色素是一种很好的天然白由基清除剂。  相似文献   

13.
芝麻中的木酚素类物质   总被引:8,自引:0,他引:8  
化学合成的抗氧剂虽然能够起到良好的抗氧化作用,但是长期或大量使用会影响身体机能,所以天然抗氧剂的开发与应用越来越受重视.芝麻中的木酚素类物质不但具有阻断自由基反应的抗氧化性能,而且已经证实具有很多生理功能.  相似文献   

14.
    
Grown predominantly in France, Ciflorette strawberries (Fragaria × ananassa ‘Ciflorette’) possess a well‐balanced fruity aroma and a sweet, creamy taste. The goal of this study was to better understand the chemical composition and key odourants of this unique fruit. Incorporating fractionation and multidimensional gas chromatography‐mass spectrometry (MDGC‐MS), the volatile constituents of Ciflorette strawberries are discussed for the first time from the large‐scale extraction of 100 kg of the pureed berries. A total of 24 volatile sulphur compounds were either absolutely confirmed by synthesis or tentatively identified from the different analyses. Three sulphur compounds were synthesized and described in nature for the first time: 1‐(methylthio)‐2,3‐butanedione, 3‐(acetylthio)‐hexanal and 2,6‐dipropyl‐3‐formyl‐5,6‐dihydro‐2H‐thiopyran. Finally, GC‐olfactometry (O) conducted by seven panelists led to the identification of 43 aroma‐active compounds in the strawberry extract. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

15.
    
Abstract: In the present study, free radical scavenging, cytotoxic, and hemolytic activities of the polyphenolic compound ethyl gallate isolated from ethanol extract of Acacia nilotica Wild. Ex. Del. leaves were determined. The free radical‐scavenging activities of the ethyl gallate were demonstrated in several in vitro assays in order to evaluate the possible antioxidant mechanism. The results revealed ethyl gallate as hydrogen donor, metal chelator, and free radical scavenger. Ethyl gallate was effective in scavenging 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radicals and the IC50 value was lower than all the positive controls used in this study. Deoxyribose degradation assay revealed that ethyl gallate had more iron‐chelating ability than the direct hydroxyl radical‐scavenging ability. The results of the cytotoxic study revealed that the compound was moderately active and IC50 value was found to be >100 μg/mL for Vero cell lines and 72 μg/mL for Hela cell lines. The compound possessed no hemolytic activity against rat and human erythrocytes revealing its cytotoxic mechanism and nontoxicity. The results from this work will provide an important information for the food and pharmacological industries with respect to the use of the compound as an antioxidant and a health‐related drug. Practical Application: Antioxidant from plant sources is safe to use, as compared to synthetic products. It also can be used as a supplement to alleviate most of the diseases because of its free radical‐scavenging activity.  相似文献   

16.
    
The antioxidant and pro‐oxidant activities of broccoli amino acids were compared with those of common food additives. In decreasing order, the data showed that Asp, SMC, GABA, Glu, Gln, Pro, Phe, Leu, Lys, Arg, Asn, Val, Ile, His, Ser, Gly, Orn and Ala, when dissolved in water at concentrations of 0.5 and 0.05 mM , partially inhibited damage to deoxyribose in the presence of ferric‐EDTA and H2O2. In contrast, Tyr and Thr acted as pro‐oxidants in this system. The amino acids present in broccoli had no hydrogen peroxide‐scavenging effect. When dissolved in water, methanol or ethanol, SMC, Glu, Thr, Gln, Ser, GABA, Pro, Ala, Ile, Phe, Asp, Orn and Tyr inhibited lipid peroxidation. However, Asn, Val, Arg, Leu, Lys, His and Gly were not effective in decreasing peroxidation at concentrations of 0.5 and 0.05 mM . Asp > SMC > Ala > Phe > Hys > Orn > Gln = Ser > Lys > Leu = GABA = Gly > Tyr > Arg = Thr > Val > Asn > Pro > Ile > Glu (p < 0.025) showed scavenging activity towards hypochlorous acid, protecting α1‐antiproteinase against inactivation. In this paper it has been established that some amino acids premixed with propyl gallate increase its hypochlorous acid‐scavenging capacity, while other amino acids have an additive effect with propyl gallate, permitting smaller quantities of propyl gallate to be used as food additives in some products which contain these amino acids. © 2001 Society of Chemical Industry  相似文献   

17.
    
Phytochemicals accessible in food have demonstrated efficiency against impairment by gamma radiation. The review presented here is an attempt to show the pharmacological outline of the activity of the natural antioxidants and its primary action of molecular mechanism against the damage induced by gamma rays. This research focused on the results of the in vitro dosage of natural antioxidants relationship, and on the correlation of this information with the statistical variables. Moreover, it deliberated the natural compounds which could decrease the unwelcome impacts of gamma radiation and safeguard biological systems from radiation-stimulated genotoxicity. The outcomes indicated that natural compounds can be utilized as an adjunct to orthodox radiotherapy and cultivate it as an effectual drug for the clinical administration of ailments.  相似文献   

18.
比较不同结构类胡萝卜素清除自由基能力。分别以虾青素、β-胡萝卜素、番茄红素和叶黄素为对象,采用DPPH法、水杨酸法和邻苯三酚自氧法分别表征清除DPPH·自由基、羟基自由基和超氧阴离子自由基能力。结果表明类胡萝卜素具有较强的清除自由基能力,且清除能力均遵循剂量-效应关系;对DPPH·自由基、羟基自由基和超氧阴离子的清除能力大小关系为虾青素叶黄素β-胡萝卜素番茄红素。类胡萝卜素清除自由基能力优良,不同结构类胡萝卜素清除自由基能力有差异,此类功能性产品具有广阔的市场前景。  相似文献   

19.
决明子水提物体外清除自由基活性的研究   总被引:20,自引:0,他引:20       下载免费PDF全文
采用超氧阴离子自由基体系、羟基自由基体系、过氧化氢自由基体系及DPPH(二苯代苦味酰肼自由基)自由基体系对决明子水提物的清除自由基活性进行了研究,并同VC进行了比较。结果表明,决明子水提物对超氧阴离子自由基、羟基自由基和过氧化氢自由基均有较好的清除作用,且清除能力高于VC;对DPPH自由基也有较好的清除作用,清除能力和VC相当。  相似文献   

20.
紫苏提取物体外清除自由基能力的研究   总被引:22,自引:1,他引:22       下载免费PDF全文
以紫苏茎、叶为研究对象,采用不同溶剂获取各种提取物,用茶多酚、维生素E、TBHQ作为对照,采用DPPH自由基体系、烷基自由基引发的亚油酸氧化体系、超氧阴离子自由基体系、羟基自由基体系,研究各种提取物对不同自由基的清除作用。结果表明,提取物对四种自由基均有清除作用,其清除效果依次为羟基自由基>DPPH自由基>烷基自由基>超氧阴离子自由基。紫苏茎、叶的95%乙醇(v/v)与碱水混合物提取物(8:2v/v)的总黄酮得率最高,紫苏叶提取物的抗氧化性强于紫苏茎提取物。   相似文献   

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