绿茶中茶多酚的分析方法研究进展

茶多酚是茶叶中一类具有强抗氧化作用的多酚类化合物的总称,具有抗氧化、抗炎、抗肿瘤、抗辐射、抗病毒等多种药理作用,其含量对茶叶的品质有非常重要的影响。但是,茶多酚结构复杂,不易准确测定,制约着对茶多酚的深入研究。综述近年来国内外对茶多酚的分析测定方法,重点阐述滴定法、红外光谱法、分光光度法、高效液相色谱法、气相色谱法等研究方法的应用和进展,为进一步研究提供参考。     

茶多酚治疗口腔疾病的研究概况

目的 为进一步开发预防和治疗口腔疾病的茶多酚制刺提供理论依据。方法 查阅茶多酚的药理活性、应用现状、制剂现状等相关文献。结果 茶多酚具有良好的抗氧化性能和显著的清除自由基能力，使其在口腔龋齿、口臭、牙周炎、口腔黏膜癌变等疾病治疗中应用广泛。结论 茶多酚适合开发成为预防和治疗口腔疾病的天然药物。     

表没食子儿茶素没食子酸酯的神经系统药理学作用及机制研究进展

表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)是绿茶儿茶素中含量最高的成分,具有抗氧化应激、抗炎性反应、调节细胞凋亡等功能,在预防和治疗肿瘤、改善肥胖和糖尿病等代谢性疾病、治疗心血管疾病和神经保护等方面有效,是茶多酚中发挥生物活性的主要成分。本文对EGCG的神经药理学作用相关的国内外文献进行检索、综述,为EGCG在神经损伤、神经退行性疾病、认知功能缺陷等预防和治疗方面的临床应用提供更多理论依据。     

茶色素体外清除氧自由基及对老龄小鼠脂质过氧化作用的影响

研究表明,茶叶中的多酚类化合物具有较强的清除体内自由基作用及抗氧化作用。以往的观点认为儿茶素类化合物氧聚合会对其活性不利,近年来也有研究表明儿茶素类氧化产物在预防肿瘤和抑菌抗病毒等方面的生物学活性并不亚于茶多酚。本实验通过一定方法制得茶色素,并测定其在体外清除Ｏ和·ＯＨ的作用和对小鼠抗氧化能力的影响,目的是为氧化产物的抗氧化作用提供实验依据。１材料与方法１．１材料１．１．１茶色素自行制备。茶多酚（ＥＧＣＧ含量大于８５ ％）氧化后用用大孔树脂和＄吵ｄ盼ｔｈ－２０进行纯化。相对分子质量分布为４３３—…     

饮茶有助抗病毒

正近年来,国外研究人员对植物多酚进行的大量科学研究证实,植物多酚具有抗氧化、抗辐射等作用。在形形色色的植物多酚中,以茶叶所含的多酚物质即茶多酚最具抗氧化效果。近期,伊朗德黑兰大学药理系研究人员对茶多酚进行了深入研究,结果表明,儿茶素是茶多酚中最主要的有效成分之一。EGCG为儿茶素中抗氧化作用最强的物质,且绿茶中的EGCG含量更高。     

茶多酚的药理作用研究进展

茶多酚（tea polyphenol）又称茶鞣质,是茶叶中多酚类物质的总称,也是茶叶中有药理和保健功能的主要成分之一。研究发现茶多酚具有抗氧化、抗炎、抗肿瘤、抗辐射、抗高血脂、延缓衰老等药理和保健作用,有关茶多酚的研究目前已成为药学领域的研究热点。查阅近年来国内外关于茶多酚药理研究的文献,简要阐述其药理作用,为新药研发提供依据。     

越南抱茎茶花的抗氧化活性研究及多酚的提取分离

目的研究越南抱茎茶花的抗氧化活性,测定总黄酮含量和茶多酚含量并分离提纯多酚化合物,为对其做进一步研究提供依据。方法通过测定羟基自由基清除率和DPPH自由基清除能力来研究越南抱茎茶花、叶及金花茶花、叶的抗氧化活性并进行比较;采用硝酸铝显色法测定4种药材中总黄酮含量,用福林酚比色法(福林酚法)测定茶多酚含量并与抗坏血酸进行比较;通过萃取、过柱、重结晶而分离提纯多酚化合物。结果越南抱茎茶花表现出相对较好的抗氧化活性;越南抱茎茶花的黄酮含量最低(1.52%),但其茶多酚含量最高(18.44%);首次从该植物中分离得到1个单体化合物没食子酸。结论越南抱茎茶花具有良好的抗氧化活性,初步认为越南抱茎茶的茶花抗氧化活性与其所含的多酚类化合物相关性比较大,结合其民间用法推测其具有较高的开发利用价值。     

绿茶化学成分及药理作用研究进展

随着茶多酚药用研究的深入,绿茶作为茶多酚含量最高的茶类,其药用价值得到了越来越多的关注。绿茶主要含有茶多酚、氨基酸、生物碱、微量元素等化学成分,研究表明其具有抗氧化、防衰老、调血脂、降血糖、抗动脉粥样硬化、抗癌、杀菌消炎、抗病毒、治疗神经退行性疾病等药理作用。归纳总结了近年来国内外对绿茶化学成分及药理作用的研究成果,以期为绿茶的后续研究、新药研发及应用提供参考。     

结构与非结构因素对黄酮类化合物抗氧化活性作用的影响

目的:为黄酮类化合物作为抗氧剂使用提供依据。方法:查阅国内、外近年来的相关文献,对结构与非结构因素对黄酮类化合物抗氧化活性作用的影响的研究进行综述。结果:黄酮类化合物B环取代羟基的数量和位置以及骨架的共轭情况对其抗氧化活性有影响;同时,疏水性、聚合度、浓度、体内的氧环境及与其他抗氧剂的协同作用等非结构因素对其抗氧化活性也有影响。结论:黄酮类化合物在生物体内具有显著的抗氧化效应,其抗氧化活性除受到自身的化学结构影响之外,还与其他非结构因素密切相关。     

市售茶饮料中茶多酚含量的测定与比较

目的：了解盐城市市售茶饮料中茶多酚的含量,并研究其影响因素。方法利用酒石酸亚铁比色法对茶饮料中的茶多酚进行测定。结果市售茶饮料茶多酚含量差别较大,其中绿茶茶饮料的平均含量为636.91mg/kg,乌龙茶和红茶茶饮料次之,花茶茶饮料中含量最低。茶多酚含量随放置时间的延长而减少,茶多酚的损失率增加,保健功能降低。结论盐城市市售茶饮料中茶多酚的含量有较大差异,并有部分样品不能达到国标要求。     

Antioxidant activities of Liquidambar formosana Hance leaf extracts

Leaves of Liquidambar formosana Hance has been be used as a rice dye for festival food by a small group of people in Guangxi province China. This study evaluated the antioxidant activities of extracts of L. formosana Hance leaves, and the effects of different extract solvents on total phenolics (TP), total flavonoids (TF), and antioxidant potential. The antioxidant activity of the extracts was assessed by using the following methods: in vitro: 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diamonium salt both free radical scavenging assays, reducing, and phosphomolybdenum assays. Antioxidant activity of the synthetic antioxidant butylated hydroxytoluene also was determined in parallel experiments for comparison. All extracts exhibited excellent antioxidant activities and were superior to butylated hydroxytoluene. The antioxidant activity and TP and TF content of various extracts seemed to follow the same trend: ethanolic extract > water extract > acetone extract. This implied that there is a good correlation between antioxidant activities and TP/TF content. In addition, UV/Vis spectra of various extracts were examined to obtain potential antioxidant compounds in assorted extracts.     

Antioxidant activity of alcoholic extract of Agrimonia pilosa Ledeb

Ultrasonically assisted extraction and Soxhlet extraction using 95% ethanol were performed to obtain ultrasonically assisted extract of Agrimonia pilosa (UEA) and Soxhlet extract of Agrimonia pilosa (SEA). The effects of the different extracting methods on the total phenolic (TP) and total flavonoid (TF) content of the extracts from Agrimonia pilosa were investigated. The findings showed that UEA contained higher TP and TF content than SEA. To understand better the effect of ultrasonic extraction, the antioxidant activities of UEA and SEA were evaluated with different antioxidant testing systems in vitro to determine reducing power, total antioxidant capacity, and free radical scavenging assays, including 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals. Both SEA and UEA exhibited satisfied antioxidant activity superior to that of synthetic antioxidant butylated hydroxytoluene (BHT). The antioxidant activity of the tested subjects was in the order of UEA > SEA > BHT. Their high phenolic and flavonoid contents could be responsible for their antioxidant activity and pharmacologic actions.     

Antioxidant properties of extracts of wild medicinal mushroom species from Croatia

Antioxidant activity and total phenol (TP) content of methanol and water extracts of three wild Croatian mushroom species Auricularia auricula-judae (Bull.) Quél., Sarcoscypha austriaca (Sacc.) Boud., and Strobilurus esculentus (Wulfen) Singer were determined and compared with the values obtained for extracts of four cultivated mushrooms Agaricus bisporus (J.E. Lange) Imbach (brown and white strains), Pleurotus ostreatus (Jacq.) P. Kumm., and Lentinus edodes (Berk.) Singer. Spectrophotometric determination of the TP content was performed using the Folin-Ciocalteu method, while antioxidant activity was measured in a reaction with 1,1-diphenyl-2-picrylhydrazyl radical (DPPH assay) and ferric-tripyridyltriazine (Fe3+-TPTZ) complex (FRAP assay). On the average, 5.8-fold higher TP content was observed for water in comparison to methanol extracts of all analyzed mushrooms. Consequently, antioxidant activity was also higher for water extracts, which is evident from the obtained higher values in the FRAP assay and lower EC50 values in the DPPH assay. Among the three tested wild species, the water extract of S. esculentus exhibited the highest concentration of TP, 8.12 mg/g gallic acid equivalents (GAE), the highest reducing power, 19.42 mmol Fe2+/kg, and the best radical scavenging properties, EC50= 13.5 mg/mL.     

The effect of dibunol on lipid peroxidation and the alpha-tocopherol level in the lungs of rats with acute blood loss]

Experiments on linear male rats were made to study the pathophysiological mechanism of the synthetic antioxidant dibunol on the levels of primary and end products of lipid peroxidation (LPO) and of alpha-tocopherol (TP) in the lungs in acute hemorrhage. Dibunol in a dose of 120 mg/kg injected 5 min after the hemorrhage inhibited LPO to the level in intact animals and raised the content of TP to the level seen in operated animals without any hemorrhage. The conclusion is drawn about a possibility of using dibunol for correction of disturbed pulmonary metabolism in urgent conditions associated with blood loss.     

Acetylcholinesterase inhibitory and antioxidant properties of Cyclotrichium niveum, Thymus praecox subsp. caucasicus var. caucasicus, Echinacea purpurea and E. pallida

The dichloromethane, ethyl acetate, ethanol, and aqueous extracts of Cyclotrichium niveum (CN) and Thymus praecox subsp. caucasicus var. caucasicus (TP), Echinacea purpurea (EPU), and E. pallida (EPA) along with the essential oils of CN and TP were assessed for their anti-acetylcholinesterase (AChE) and antioxidant activities. AChE inhibition was estimated using spectrophotometric method of Ellman. Antioxidant activity was evaluated by 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferrous ion-chelating power tests. Ferric-reducing antioxidant power (FRAP) of CN and TP were also tested. CN essential oil was found to contain isomenthone (56.21%) and pulegone (19.76%). The ethyl acetate (83.11–87.98%) and dichloromethane (73.45–84.02%) extracts of CN showed the highest AChE inhibition. The ethyl acetate and ethanol extracts of TP exerted significant DPPH scavenger effect. The water extracts of CN and TP and the chloroform extract of the aerial parts of EPU displayed the highest ferrous ion-chelating effect. The leaf and flower essential oils of TP had the best FRAP.     

低聚甘露糖醛酸磷酸酯的制备及其抗氧化活性探究△

目的 旨在探究不同取代度的低聚甘露糖醛酸磷酸酯的体外抗氧化活性。方法 采用磷酸-脲素法制备了3种不同取代度的磷酸化衍生物,然后测定了三种磷酸化多糖的体外抗氧化活性,包括清除超氧自由基、1,1-二苯基-2-吡啶酰肼(DPPH)自由基、羟基自由基及还原能力。结果 通过控制磷酸用量,制备了三种含磷量为3.90%、5.14%和6.56% 的单磷酸酯衍生物;与原料相比,低聚甘露糖醛酸磷酸酯衍生物的抗氧化活性增强;并且随着磷含量的增加,磷酸酯衍生物的羟基自由基、DPPH自由基清除活性及还原力也增强。结论 适当的磷酸化修饰可以显著提高低聚甘露糖醛酸的体外抗氧化活性,为海洋多糖的应用开发提供了借鉴。     

Sulfur-containing antioxidants increase in vitro several functions of lymphocytes from mice

The in vitro effects of several sulfur-containing antioxidants, such as glutathione (GSH), N-acetylcysteine (NAC), thioproline (TP) and taurine (TAU), at different concentrations, on key functions of lymphocytes from axillary nodes, spleen, thymus and peritoneum from young-adult BALB/c mice have been investigated. The functions studied have been proliferation, both spontaneous and in response to the mitogen Concanavalin A, mobility both spontaneous and directed to a chemical attractant (chemotaxis) and adherence to substrate. The effect of these antioxidants on the viability of leukocytes was also investigated. The results show an antioxidant-induced stimulation of all the functions studied. The highest concentrations used of each antioxidant were the most effective in proliferation (5mM for GSH, 1mM for TP and NAC and 40 mM for TAU). These concentrations increase mobility significantly. The presence of TP+NAC enhances the chemotaxis of peritoneal lymphocytes more than each antioxidant separately. The adherence capacity of peritoneal lymphocytes also increased at 10 min of incubation with GSH, TP and NAC. All these antioxidants increase the viability of leukocytes in culture, especially in cells from spleen. In conclusion, the sulfur-containing antioxidants studied in vitro improve the functional capacity of lymphocytes from young-adult mice and these results showing that the improvement of the immune response, and specifically of the lymphocyte functions, found after ingesting diet supplemented with the antioxidants studied, are due to a direct action of these compounds in the immune cells.     

Thiolic antioxidant supplementation of the diet reverses age-related behavioural dysfunction in prematurely ageing mice

We have studied in a model of premature ageing in mice based on their impaired behavioural response in a simple T-maze test the effect of the ingestion of thioproline (TP) plus N-acetylcysteine (NAC) (0.1% w/w of each antioxidant) by female and male mice of Swiss and BALB/c strains on performance in two behaviour tests. The antioxidant treatment (4 weeks in two different periods of life, i.e., adult and old age) protected all animals against early-age-associated behavioural impairment, but this improvement was more evident in the prematurely ageing mice (PAM) in comparison to the control group or non-prematurely ageing mice (NPAM). An improvement of the exploratory activity and neuromuscular coordination after the thiolic antioxidant treatment was found in the PAM, bringing the behavioural parameters to the NPAM levels. These effects could be due to the glutathione precursor role of NAC and TP that replenish the intracellular reduced glutathione (GSH) levels despite advancing age. In conclusion, diet supplementation with thiolic compounds appears to be an effective therapy for protection against early behavioural decline in prematurely ageing mice.     

茶色素体外抗氧化作用研究

目的研究茶色素（TP）体外抗氧化作用。方法通过邻苯三酚自氧化和抗体外氢氧根法分别测定TP与阳性对照药维生素C的抗氧化作用,比较两者作用程度。结果0.1%,0.2%,0.3%TP对邻苯三酚自氧化平均抑制率分别为每分钟7.022%,13.427%,16.910%;0.1%,0.2%维生素C分别为16.340%,32.850%。TP与维生素C对邻苯三酚自氧化平均抑制率呈剂量依赖式增加。0.1%,0.3%,0.5%,0.7%,1.0%TP对体外羟自由基（•OH）生成的平均抑制率分别为（11.00±0.70）%,（20.68±0.60）%,（27.04±0.07）%,（32.70±0.30）%,（42.90±0.70）%;0.1%,0.3%,0.5%,0.7%,1.0%维生素C对体外•OH生成的平均抑制率分别为（4.50±0.30）%,（7.40±1.00）%,（11.42±0.23）%,（14.80±0.40）%,（16.80±0.60）%。TP和维生素C对体外•OH生成抑制率均呈剂量依赖性增加。TP和维生素C对体外•OH生成均有一定抑制作用,TP抑制作用较维生素C显著。相同剂量维生素C 和TP抑制作用差异有统计学意义（P＜0.01）;不同剂量TP对体外•OH生成的抑制作用差异有统计学意义（P＜0.05）。结论TP体外具有抗氧化作用,尤其是在体外抗氢氧根作用方面。     

没食子酸药理作用的研究进展

没食子酸作为我国传统中药材五倍子、石榴、掌叶大黄等的主要成分之一,是化学结构最简单的天然多酚类化合物。没食子酸具有抗炎、抗氧化、抗菌、抗病毒等多种生物活性,为疾病治疗提供了广阔的应用前景。没食子酸对心血管系统疾病、神经系统疾病、糖尿病、肝纤维化和肿瘤等具有防治作用,与其抗炎、抗氧化生物活性息息相关。本文对近五年来国内外对没食子酸药理作用及其作用机制研究进行综述,以期为没食子酸的深入研究和发展应用提供参考。