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1.
Lipophilic tea polyphenols (LTP) were prepared by catalytic esterification of green tea polyphenols (GTP) with hexadecanoyl
chloride. A novel long-chain acyl-derivative of epigallocatechin-3-o-gallate (EGCG) was first isolated from purification of LTP by high-speed countercurrent chromatography (HSCCC) using a solvent
system composed of n-hexane-ethyl acetate-methanol-water (1∶1∶1∶1, v/v). The molecular structure of the acyl-derivative, Epigallocatechin-3-O-gallate-4′-O-hexadecanate, was elucidated by means of elemental analysis, IR,1H-NMR and MS spectra.
Project (No. 200010) supported by Zhejiang Provincial Natural Science Foundation, China 相似文献
2.
采用高效液相色谱法对3种不同发酵类型的茶叶中茶多酚的含量进行测定和比较分析．方法的变异系数小于4．38％,回收率为96．6％～104．0％．其分析结果为：3种不同发酵类型的茶叶中茶多酚的含量由多到少的顺序为：不发酵的绿茶,半发酵青茶,全发酵红茶,即茶叶中茶多酚的含量随着发酵程度增大而减少． 相似文献
3.
茶多酚是茶叶中多酚类物质的总称,在食品、油脂、保健、医药、日化、精细化工等领域都有广泛的应用。茶多酚的提取和应用研究成为国内外开发“绿色工程”的热门课题之一。本文研究的内容是茶叶中茶多酚的提取与测定,主要目的是测定茶叶在不同条件下荼多酚的含量,然后相互比较。例如：茶汤放置时间,泡茶次数及pH对茶多酚含量的影响。随着人们保健意识的增强,都希望自己每日饮用的茶水中的茶多酚的含量多一些,因此我们研究了不同条件下从茶水中获得茶多酚的最佳条件。 相似文献
4.
研究了自制交联PVP（聚乙烯吡咯烷酮）凝胶对绿茶茶水浸取液中的茶多酚的吸附。结果表明：在室温下，对2mLTP试液，用4mL交联PVP凝胶，吸附60min，茶多酚的除去率达到50％以上。其吸附机理为：交联剂的活性吸附中心与茶多酚上的酚羟基形成氢键。 相似文献
5.
目的:观察茶多酚对D-半乳糖所致亚急性衰老小鼠皮肤光老化程度的影响,探讨茶多酚延缓皮肤光老化作用。方法:用紫外线模拟日光照射建立小鼠皮肤光老化模型,给以茶多酚灌胃及外涂治疗,结束后测定皮肤中丙二醛(MDA)和超氧化物歧化酶(SOD),以及皮肤中成纤维细胞数目和羟脯氨酸含量。结果:模型小鼠与正常小鼠比较,MDA含量升高而SOD活性下降,成纤维细胞数目和羟脯氨酸含量明显下降;茶多酚可明显提高光老化小鼠皮肤中SOD活性以及成纤维细胞数目和羟脯氨酸含量,并使皮肤MDA含量降低。结论:茶多酚具有延缓皮肤光老化作用。 相似文献
6.
采用超声波提取茶叶中的茶多酚,并应用高效液相色谱法对不同品种的茶叶及同一产地不同档次的茶叶中的茶多酚成份进行分析测定.结果表明,采用Hyper-sil ODS柱,超纯水、甲醇和0.36%的乙酸为流动相,梯度洗脱,流速为0.8 mL.min-1,柱温40℃,在280 nm波长处可对儿茶素进行检测,其线性范围为0.6~3.0 g.L-1,R为0.999 6~0.999 9. 相似文献
7.
对茶寄生中茶多酚的含量进行分析．茶多酚是混合物,由于各种茶多酚结构相似,较难分离．没食子酸（EC）、表没食子儿茶素（EGC）、没食子儿茶素没食子酸酯（EGCG）、表儿茶素没食子酸酯（ECG）4种茶多酚是茶叶中茶多酚的主要成分．本研究采用高效液相色谱（ HPLC）法同时测定了EC、EGC、EGCG、ECG 4种茶多酚,4种茶多酚在15 min内达到有效分离,方法的变异系数小于0．0360％,回收率为95．2％～104．2％．实验结果表明,茶寄生样品中只含有茶多酚中的EGC,其中云南粗茎茶寄生样品中的EGC含量略高于云南细茎茶寄生样品中EGC含量． 相似文献
8.
Tea is one of the most popular beverages, consumed by over two thirds of the world's population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminum's known adverse effect on human health. Investigation of the interactions of catechins with Al3 showed that during the interaction of catechins with Al3 , the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322 nm; EC and C's at 278 nm changed little. The ratio of Al3 to EGCG was 1:1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the Al-EGCG complex was 1:1. Interestingly, while the ratio reached to over 2, after the complex of Al-EGCG started polymerization, the ratio in the polymer was 2:1. In pH 6.2 buffer solution, the complex behavior of C with Al3 was the same as that of EGCG, with a little difference for EC. When the ratio of Al3 to EC was <1, the complex in ratio was 1:2, but, the complex polymerized when the ratio of Al3 to EC was >1. It was found that the ratio of Al3 to EC in the polymer was 1:1. Polymerization of Al-catechin complexes might reduce aluminum absorption in the intestine. Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols on Kow in buffer solution. Results showed that Kow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminum Kow value in acetic buffer, indicating that these compounds may reduce aluminum absorption during tea intake. 相似文献
9.
紫外光谱法比较乌龙茶和乌龙茶嫩茎中的茶多酚含量 总被引：2，自引：0，他引：2
用水溶剂提取乌龙茶和乌龙茶嫩茎中的茶多酚成分,利用紫外光谱法进行分析,乌龙茶和乌龙茶嫩茎中茶多酚的最大吸收波长均在540 nm处,乌龙茶和乌龙茶嫩茎的茶多酚含量分别为26.4%和10.3%. 相似文献
10.
电位滴定法测定茶叶中茶多酚的含量 总被引：1，自引：0，他引：1
该文建立了电位滴定法测定茶叶中茶多酚含量的定量分析方法.以高锰酸钾为氧化剂,在硫酸强酸性介质中,用待测样品试液进行电位滴定,用一阶微分法确定待测样品试液的滴定终点体积,方法的RSD为4.07%(n=5),平均回收率为99.6%,该法准确、简便,可用于茶叶中茶多酚含量的测定. 相似文献
11.
通过对普洱茶的特级、三级、九级三个茶样进行五分钟沸水冲泡处理,测出相应的茶多酚和游离氨基酸含量．探讨普洱茶在冲泡过程中,茶多酚和游离氨基酸的浸出规律．研究表明：随着级别的降低,茶多酚和氨基酸含量明显减少;随着冲泡次数的增加,茶多酚和氨基酸的浸出含量也随之减少． 相似文献
12.
Influence of green tea polyphenols on mitochondrial permeabi lity transition pore and Ca2+ transport
The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mit ochondria swelling and change of mitochondria membrane potential. The data showe d that GTPs had obvious protective effect on the Ca2+-induced PTP opening in a d ose-dependent manner detected by mitochondria swelling. The results were obtain ed by measuring the change of mitochondria membrane potential through Rh 123. Further experiments were conducted to examine the detailed influence of GTP s on Ca2+import and export of mitochondria. The results showed that GTPs h ad rem arkably inhibitory effect on the Ca2+-induced Ca2+ import in mitoch ondria; and t hat they could accelerate Ca2+-release from mitochondria. Our data provid e an al ternate interpretation of the potent protective function of GTPs on cell against apoptosis. 相似文献
13.
石丽荣 《Journal of Zhangzhou Technical Institute》2012,14(2):26-31
以加工后的废弃的龙眼壳为研究对象,研究龙眼壳多酚的提取工艺。单因素和正交实验结果表明,用乙醇提取该多酚的最佳工艺为：用浓度50％的乙醇,以1g：15mL的料液比,在50℃下提取1h。照此工艺浸提,龙眼壳多酚的得率为2．71％。 相似文献
14.
以海带多酚为研究对象,考察提取温度、料液比和超声时间对海带游离多酚和结合多酚提取率的影响、采用正交试验对多酚提取工艺进行优化,并通过测定多酚对DPPH自由基的清除能力评估其抗氧化性.结果表明,海带多酚的最佳提取工艺为:料液比为1:30(g/mL)、提取温度为40℃、超声时间为30 min.在此工艺条件下,海带总多酚的提取率为2.74%.当浓度为2.0 mg/mL时,游离多酚和结合多酚对DPPH·的清除率分别为41.72%和19.37%,表明海带多酚具有一定的抗氧化活性,且游离多酚的抗氧化活性高于结合多酚。 相似文献
15.
以紫阳群体种茶树鲜叶为试材,以铁观音品种茶树鲜叶为对照（CK）,研究了采摘标准和做青强度对乌龙茶的生化成分变化和品质的影响。结果表明,各采摘标准的茶树鲜叶生化成分含量差异显著,以小开面最丰富,中开面次之、大开面最差;加工过程中茶多酚、水浸出物、咖啡碱的含量减少,氨基酸有所增加;茶多酚和水浸出物持续减少,做青强度越大减少幅度越大,氨基酸和咖啡碱的增减变化还与鲜叶原料有关。各处理之间成茶感观品质差异显著,所有处理除了小开面重做青茶样与CK品质差异不显著外,其他均与CK差异显著。还提出了利用紫阳群体种茶树鲜叶进行乌龙茶加工的工艺。 相似文献
16.
鲍晓华 《思茅师范高等专科学校学报》2013,(3):1-10
云南省分布着大量的古茶园,普洱市澜沧县惠民古茶园是典型的栽培型古茶园,约有130年,古茶园的茶具有美好的香气和品质特征,被普洱市当地人奉为上品,特别是在自然环境下贮藏几年后,香气和优良的品质特征更为明显,为揭示古茶园茶香气和品质特征的变化,让人们进一步了解、认识普洱茶;采用感官审评和化学分析手段,对古茶园茶的外形、颜色、滋味、香气等进行审评和测定。贮藏在自然环境下1～6年,汤色由淡黄色变为红黄色,地域香变为淡淡陈香,滋味由微苦涩纯正味长回甘变为入口微涩微苦、舌底微涌泉、醇感、滑顺、味长、纯正;可溶性糖、黄酮类化合物、TR和TB分别增加0．5％、4．96％、0．565％和0．395％;茶多酚、咖啡碱、游离氨基酸和TF分别减少6．13％、2．63％、1.04％和0．068％。为普洱茶的研究提供数据．便于古茶园茶能更好的加以利用。 相似文献
17.
Hui Zhou Yan Chen Shu-wei Huang Peng-fei Hu Li-jiang Tang 《Journal of Zhejiang University. Science. B》2018,19(5):333-341
Objective
To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyopathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy.Methods
Sixty Sprague-Dawley (SD) rats were randomly divided into six groups: a normal control group (NC), an obesity group (OB), a diabetic cardiomyopathy group (DCM), a tea polyphenol group (TP), an obesity tea polyphenol treatment group (OB-TP), and a diabetic cardiomyopathy tea polyphenol treatment group (DCM-TP). After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ultrasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-II, SQSTM1/p62, and Beclin-1 were determined by Western blotting.Results
Compared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-II/I and Beclin-1 increased obviously, whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups (P<0.05).Conclusions
Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.18.
不同工艺对茶多酚提取效率和质量的影响研究 总被引：1，自引：0，他引：1
本文比较分析了目前从茶叶中提取茶多酚的四种工艺的主要特点和不足,并比较了工艺条件对茶多酚的提取效率和质量的影响.结果表明,提取率较好,茶多酚含量较高是金属离子盐沉淀和树脂吸附茶多酚提取工艺. 相似文献
19.
周建刚 《湖南城市学院学报》2012,(1):31-35
唐代社会饮茶风气盛行,禅宗僧人在其中起了有力的推动作用。唐宋时期寺院的饮茶活动主要有两种:一是交际式的"茶筵";二是礼仪式的"茶会"。茶筵起于唐,由文人茶宴转化而来,形式较为自由;茶会盛于宋以后,模仿世俗社会的礼制,有严格的礼仪要求。唐宋时期寺院"茶筵"、"茶会"和"茶汤礼"的沿革演变,反映出唐宋禅宗的世俗化转变已由思想文化而深入到制度文化的层面。 相似文献
20.
Dong-mei Fan Kai Fan Cui-ping Yu Ya-ting Lu Xiao-chang Wang 《Journal of Zhejiang University. Science. B》2017,18(2):99-108
Polyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months. The release patterns of nitrogen, potassium, calcium, and magnesium were also determined. The decomposition pattern of tea leaf litter could be described by a two-phase decomposition model, and the polyphenol/N ratio effectively regulated the degradation process. Most of the catechins decreased dramatically within two months; gallic acid (GA), catechin gallate (CG), and gallocatechin (GC) were faintly detected, while others were outside the detection limits by the end of the experiment. These results demonstrated that tea polyphenols transformed quickly and catechins had an effect on the individual conversion rate. The nutrient release pattern was different from other plants which might be due to the existence of tea polyphenols. 相似文献