Caffeic and chlorogenic acids in Ilex paraguariensis extracts are the main inhibitors of AGE generation by methylglyoxal in model proteins

The present study concentrates on the evaluation of the anti-glycation effect of some bioactive substances present in yerba maté (Ilex paraguariensis): 5-caffeoylquinic acid, caffeic acid and a sapogenin (oleanolic acid). Bovine serum albumin and histones were incubated in the presence of methylglyoxal with or without the addition of 5-caffeoylquinic acid, caffeic acid and oleanolic acid. After the incubation period, advanced glycation end product (AGE) fluorescence spectra were performed and protein structural changes were evaluated by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis. Chlorogenic acid, caffeic acid are the main substances responsible for the anti-glycation effect of maté tea.     

The protection of 4,4′-diphenylmethane-bis(methyl) carbamate from Cortex Mori on advanced glycation end product-induced endothelial dysfunction: Via inhibiting AGE formation or blocking AGEs–RAGE axis?

Advanced glycation end products (AGEs) were implicated in the pathogenesis of endothelial dysfunction in diabetic vascular complications. Our previous study found that a novel compound 4,4′-diphenylmethane-bis(methyl) carbamate (CM1) from Cortex Mori (Morus alba L.) could attenuate AGE-induced endothelial dysfunction. The present study was conducted to explore the possible protective mechanisms of CM1 on AGE-induced endothelium damage. In binding experiments, fluorescence quenching and fluorescence polarization assays showed no significant difference or changes of AGEs on fluorescence intensity and polarization in the absence/presence of CM1. In AGE formation experiments, CM1 was incubated with AGE precursor compounds methylglyoxal (MGO), glyceraldehydes (Glycer) and glycolaldehyde (Glycol) in the formation system. However, high performance liquid chromatography (HPLC) analysis showed no new conjugated compounds formed in the reaction system. The results of ELISA analysis also showed that CM1 did not inhibit the AGE formation. However, the pretreatment with CM1 could significantly decrease AGE or high-mobility group box-1 (HMGB1, a ligand of RAGE)-induced cytotoxicity, apoptosis and reactive oxygen species (ROS) in human umbilical vein endothelial cells (HUVECs). Our results suggested that CM1 might block the AGEs–RAGE signal transduction rather than inhibit AGE formation or bind to AGEs and change its structure to prevent endothelial dysfunction in diabetic vascular complications.     

"湘妃翠"鲜叶与成品茶主要品质成分的季节变化

采用氨基酸自动分析仪、高效液相色谱和茶叶国标检测方法测定分析了不同季节“湘妃翠”鲜叶及其成品茶中游离氨基酸、儿茶素、咖啡碱、茶多酚和水浸出物的含量。结果表明:鲜叶与成品茶中游离氨基酸、儿茶素、咖啡碱、茶多酚和水浸出物含量等的品质成分的季节变化明显,趋势一致,春季明显优于夏秋季、秋季优子夏季;与鲜叶的品质成分状况相比,成品茶的品质成分状况明显改善,奠定了感官品质的生化基础。根据分析结果提出了“湘妃翠”品种在夏秋季生产普通绿茶而不生产名优茶的建议。     

Advanced glycation inhibition and protection against endothelial dysfunction induced by coumarins and procyanidins from Mammea neurophylla

Advanced glycation end-products (AGEs) are associated with many pathogenic disorders such as pathogenesis of diabetes or endothelial dysfunction leading to cardiovascular events. Therefore, the identification of new anti-AGE molecules or extracts aims at preventing such pathologies. Many Clusiaceae and Calophyllaceae species are used in traditional medicines to treat arterial hypertension as well as diabetes. Focusing on these plant families, an anti-AGE plant screening allowed us to select Mammea neurophylla for further phytochemical and biological studies. Indeed, both DCM and MeOH stem bark extracts demonstrated in vitro their ability to prevent inflammation in endothelial cells and to reduce vasoconstriction. A bioguided fractionation of these extracts allowed us to point out 4-phenyl- and 4-(1-acetoxypropyl)coumarins and procyanidins as potent inhibitors of AGE formation, potentially preventing endothelial dysfunction. The fractionation steps also led to the isolation of two new compounds, namely neurophyllols A and B from the DCM bark extract together with thirteen known mammea A and E coumarins (mammea A/AA, mammea A/AB, mammea A/BA, mammea A/BB, mammea A/AA cycloD, mammea A/AB cycloD, disparinol B, mammea A/AB cycloE, ochrocarpin A, mammea A/AA cycloF, mammea A/AB cycloF, mammea E/BA, mammea E/BB) as well as δ-tocotrienol, xanthones (1-hydroxy-7-methoxyxanthone, 2-hydroxyxanthone) and triterpenes (friedelin and betulinic acid). During this study, R,S-asperphenamate, previously described from fungal origin was also purified.     

Anti-cariogenic effects of polyphenols from plant stimulant beverages (cocoa,coffee, tea)

Polyphenols occurring in cocoa, coffee and tea can have a role in the prevention of cariogenic processes, due to their antibacterial action. Cocoa polyphenol pentamers significantly reduce biofilm formation and acid production by Streptococcus mutans and S. sanguinis. In the same way, trigonelline, caffeine and chlorogenic acid occurring in green and roasted coffee interfere with S. mutans adsorption to saliva-coated hydroxyapatite beads. Studies carried out on green, oolong and black tea indicate that tea polyphenols exert an anti-caries effect via an anti-microbial mode-of-action, and galloyl esters of (−)-epicatechin, (−)-epigallocatechin and (−)-gallocatechin show increasing antibacterial activities. The anti-cariogenic effects against α-haemolytic streptococci showed by polyphenols from cocoa, coffee, and tea suggest further studies to a possible application of these beverages in the prevention of pathogenesis of dental caries.     

The importance of being red when young: anthocyanins and the protection of young leaves of Quercus coccifera from insect herbivory and excess light

Young leaves of many plants are transiently red because of the accumulation of anthocyanins, with the redness disappearing as leaves mature. Among the many hypothetical functions of foliar anthocyanins, two are tested in this field study: the sunscreen photoprotective function against excess visible light and the handicap signal against herbivory. We took advantage of intraspecies variation in anthocyanin concentrations of young leaves of Quercus coccifera L. to compare in vivo chlorophyll fluorescence parameters, reflectance spectra, total phenolics and the extent of herbivory of leaves of red- and green-leaved phenotypes occupying the same habitat. Photosystem II (PSII) photochemical efficiencies obtained at various photon fluence rates of red light were similar in green and red leaves. In white light, PSII efficiencies were slightly higher in red leaves than in green leaves, indicating a slight photoprotective role of anthocyanins in the field. However, compared with red phenotypes, green phenotypes suffered greater herbivore damage, as judged by the number of leaves attacked and the area lost to herbivory. In addition, there was a positive correlation between the concentrations of anthocyanins and total phenolics. We suggest that the importance of a photoprotective anthocyanic screen is low in thin, young leaves with low chlorophyll concentrations because the green light attenuated by anthocyanins is less significant for chlorophyll excitation. However, the decreased reflectance in the green spectral band and the concomitant leveling of reflectance throughout the 400-570 nm spectral range may either make red leaves less discernible to some insect herbivores or make insect herbivores more discernible to predators, or both. Moreover, excessive herbivory may be additionally discouraged by the high phenolic concentrations in red leaves.     

Investigation into the antioxidant activity and chemical composition of alcoholic extracts from defatted marigold (Tagetes erecta L.) residue

The influence of various solvents on the yield of polyphenols from defatted marigold residue, the antioxidant activity of the extracts and the composition of antioxidant compounds in the extracts were investigated. The content of total phenolics and flavonoids in the extracts was significantly varied with different solvents (P<0.05) and the extract by ethyl alcohol (EtOH)/water (7:3, v/v) has the highest content of total phenolics and flavonoids, 62.33 mg gallic acid equivalents (GAE)/g and 97.00 mg rutin equivalent (RE)/g, respectively. The antioxidant activity of the extracts was evaluated by radical (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH)) scavenging and ferric reducing antioxidant power (FRAP) assays. The results of the correlation analysis showed that the antioxidant activity was well correlated with the content of total phenolics and flavonoids (R2>0.900). Antioxidant components in the extracts were identified by combined on-line HPLC-ABTS·+ post-column assay and HPLC-DAD-MS method. Gallic acid, gallicin, quercetagetin, 6-hydroxykaempferol-O-hexoside, patuletin-O-hexoside and quercetin were the dominant antioxidant compounds in the extracts, and quercetagetin was identified as the strongest antioxidant capacity.     

加工工艺对名优茶品质影响的研究

以狗脑贡茶、东江银毫茶、汝白银毫茶湖银毫茶为对象，探讨加工工艺对名优茶品质的影响。研究结果表明：适宜的摊青工艺有利于提高名优茶品质，尤其是对高山茶返修青时间适当延长其品质越好；高档名优茶的制作采用机械杀青能很好地达到杀青特别针对高海拔地区和水库库区茶叶的杀青，还牟提高品质；高山茶以不揉捻为好，有利于保证绿茶类名茶色泽翠绿多毫。     

Antioxidant activity of extracts from the wood and bark of Port Orford cedar

Heartwood, sapwood, and inner and outer bark of Port Orford cedar were extracted with methanol, and the extracts evaluated for antioxidant activity. The total phenol content (TPC) of the extracts was determined by the Folin-Ciocalteu method and expressed as gallic acid equivalent (GAE). Butylated hydroxytoluene was used as a positive control in the free-radical-scavenging activity tests and ethylenediaminetetraacetic acid dihydrate disodium salt served as a positive control in the metal-chelating activity assay. All wood extracts showed significant freeradical-scavenging activity. In the radical-scavenging assay of 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (the ABTS assay), the inner bark extracts exhibited the strongest free-radical-scavenging activity. The 50% inhibitory concentrations (IC₅₀) in the radical-scavenging assay against 1,1-diphenyl-2-picrylhydrazyl hydrate radical (DPPH) of the heartwood, sapwood, and inner and outer bark extracts were 64.77, 29.03, 10.31, 19.87 μg·ml⁻¹, respectively. In the metal-chelating activity system, the sapwood extract demonstrated significant activity. The greatest TPC, 537.5 mg GAE/g dry extract, was detected in the inner bark. The lowest TPC of 136.9 mg GAE/g dry extract was observed in the heartwood dry extract. The results indicate that the antioxidant activities of the extracts are in accordance with the amounts of phenolics present; the inner and outer barks of Port Orford cedar are rich in phenolics and may provide good sources of antioxidants.     

竹炭对茶叶贮藏品质影响的动态分析初报

分析了竹炭对炒青绿茶贮藏过程中的含水率、叶绿素含量、茶多酚含量、咖啡碱含量及氨基酸含量动态变化情况.结果表明,在8个月的贮藏期中,竹炭处理使茶叶的含水率增加率控制至31.47%,而空白对照则达54.61%;试验结果同时表明,竹炭处理使茶叶叶绿素、茶多酚、咖啡碱、氨基酸的保留率得以不同程度提高,分别为空白对照的114.56%、106.70%、103.24% 和111.81%.     

中国茶产业发展现状分析

我国茶园总面积、茶叶总产量及绿茶、特种茶、乌龙茶出口创汇呈现持续上升的态势;茶叶功能成分的深度开发与利用,使得茶叶提取物作为膳食补充剂、医药原料及化妆品原料等在国际市场上呈急剧攀升之势。对比分析茶叶等植物原材料的销售产值与茶叶等植物提取物的销售产值,指出在世界茶产业面临供过与求的情况下,扬长避短,生产绿茶、特种茶、乌龙茶等具有国际竞争力的茶叶产品,加大茶叶深加工产品的开发与利用,出口符合国际保健品市场需要的茶叶功能产品,促进茶产业升级换代,是我国茶产业经济增长及发展的重要途径。     

Antimicrobial activities of Alchornea cordifolia

The antimicrobial properties of methanol extracts of Alchornea cordifolia leaves, stem and root barks were investigated. The most active leaf extract was separated by PTLC into 32 fractions which were submitted to further phytochemical and antimicrobial screening. Some fractions, notably those containing phenolics and terpenoids, exhibited significant activity against Pseudomonas aeruginosa, Bacillus subtilis and Escherichia coli.     

无公害施肥对茶园土壤理化性质的影响[]

文章研究无公害施肥对粤东乌龙茶茶园土壤自然含水量和土壤容重等物理性质、有机质、全氮、碱解氮等土壤养分的影响,结果表明：铺草、施绿肥、施有机肥均能提高土壤自然含水量和有机质质量比,而施有机肥对提高土壤有机质质量比的效果最好;施绿肥和铺草对于提高土壤全氮和碱解氮质量比的效果不明显,而施有机肥可以明显提高土壤全氮和碱解氮质量比,因此粤东各地茶园可以因地制宜改善本地的茶园土壤,采取施有机肥结合铺草措施,保证土壤肥力供应和含水量。     

N-(2-亚甲基吡啶)脱氢枞胺希夫碱及其铜配合物与牛血清白蛋白的作用研究

运用紫外光谱、荧光光谱和圆二色谱研究了具有抗癌活性的N-(2-亚甲基吡啶)脱氢枞胺希夫碱(L)及其铜配合物[Cu(L)2Br]Br(1)在模拟生理条件(p H值7.2)下与牛血清白蛋白(BSA)的相互作用,分析了它们之间相互作用的机制。结果表明,1对BSA的荧光猝灭方式为静态猝灭,L为动态猝灭;通过计算得到了不同温度下的结合常数(Ka)、结合位点数(n)及相关的热力学参数(ΔG0、ΔH0和ΔS0),表明L和1与BSA的相互作用力以疏水作用为主,且结合反应是由焓和熵驱动的自发过程。同步荧光光谱分析表明,化合物与BSA的作用使蛋白质的构象发生改变,圆二色谱也证明了化合物能够显著改变BSA的构象,由典型的α-螺旋结构变为扭曲链。     

Synergetic deodorant effect and antibacterial activity of composite paper containing waste tea leaves

Composite paper containing waste tea leaves was prepared to investigate the effective utilization of waste tea leaves as deodorant material. Paper containing waste green tea leaves did not have increased deodorizing ability compared with controls either against acidic odors such as hydrogen sulfide and acetic acid gases or against neutral odors such as formaldehyde and acetaldehyde gases. In contrast, the paper had excellent deodorizing ability against basic odors such as ammonia and trimethylamine gases. It was observed during additional tests conducted on paper samples containing 60 wt% waste leaves of oolong tea, black tea, pu-erh tea, or hojicha, that all the samples reduced the ammonia concentration to below 1 ppm, which is the threshold concentration for olfactory recognition, within 30 min. Further, paper containing waste green tea leaves was found to decrease the odor residual rate to 5.1% in 30 min even for a waste tea leaf content of 10 wt%. The excellent deodorizing ability of the paper could be attributed to the chemical reactions between odorous substances and the catechins found in tea leaves. After the deodorization of ammonia, paper containing waste green tea leaves was found to have increased antibacterial activity against Staphylococcus aureus.     

松茸速溶茶配方设计研究

松茸在防癌、抗肿瘤、降低血糖、提高机体免疫力、防治心血管疾病等方面效果显著;绿茶中营养成分众多,也具有很好的保健功能。以绿茶和松茸为原料研究的松茸速溶茶,既具有松茸的营养功效,又保留了绿茶的清香高爽,饮用方便。结果表明：确定绿茶浸提的最佳参数为：料液比1∶13,温度为65℃,浸提时间为40min;松茸速溶茶的最佳配方为：松茸多糖浸提液与绿茶浸提液比例为1∶5,柠檬酸为0．04％,甜味剂为10％（白砂糖∶蜂蜜＝3∶2）,产品为浅棕色、颜色发亮,具有松茸和绿茶特有的香味,酸甜可口,感官评定得分为92．1。     

In vitro antifungal activities of Allium cepa, Allium sativum and ketoconazole against some pathogenic yeasts and dermatophytes

By using an agar dilution assay, the antifungal activity of aqueous extracts prepared from Allium cepa (onion; AOE) and Allium sativum (garlic; AGE) were evaluated against Malassezia furfur (25 strains), Candida albicans (18 strains), other Candida sp. (12 strains) as well as 35 strains of various dermatophyte species and compared with the activity of a known antifungal drug, ketoconazole (KTZ). All the AOE, AGE and KTZ were found to be able to inhibit growth of all fungi tested in a dose-dependent manner with maximum of 100% at defined concentrations. The results indicate that onion and garlic might be promising in treatment of fungal-associated diseases from important pathogenic genera Candida, Malassezia and the dermatophytes.     

Epigallocatechin gallate content change of the fresh tea leaf homogenates extracted by different methods in extraction and preservation

Introduction Tea polyphenols, extracted from tea leaves, is a hydroxyl phenol compound. Of the components of green tea (Camellia sinensis), the content of (?)-epigallocatechin gallate (EGCG) is high, and this catechin has been extensively studied (Harold …     

湖南特种绿茶的主要化学成分

测定和分析了湖南省25只具代表性的特种绿茶的主要生化成分。结果表明：特种绿茶的全氮、游离氨基酸和咖啡碱的含量均高于普通绿茶，而可溶性糖和粗纤维的含量则低于普通绿茶；就品质成分来分析，产于山区的特种绿茶优于产于丘陵区的；茶树品种和原料嫩度均影响特种绿茶的主要生化成分含量。根据研究结果，作者提出了湖南名优茶在生产时间上限制在早春，在生产布局上应以山区为主，结合有特殊条件的其他地区来发展名优茶，在生产原料上，应以一芽一叶为主，适当考虑有特色的茶芽和一芽二叶初展的情况。     

Anti-diabetic effect of American ginseng may not be linked to antioxidant activity: Comparison between American ginseng and Scutellaria baicalensis using an ob/ob mice model

Antioxidants have been considered as a useful remedy in diabetes therapeutics, and thus, herbal medicines with antioxidant properties may play major role in treating diabetes. In this report, we performed a comparative study using American ginseng and Scutellaria baicalensis to test whether the anti-diabetic effect of American ginseng is associated with its antioxidant activity. We used a simple water extraction procedure to prepare American ginseng root extract (AGE) and S. baicalensis extract (SbE), and utilized these two antioxidant herbs to evaluate their anti-diabetic effect in obese diabetic ob/ob mice. HPLC analysis was used to identify major constituents in the AGE and SbE. After 12 days of daily intraperitoneal injection, AGE at 300 mg/kg showed significant effects on fasting blood glucose levels (P < 0.01) and glucose tolerance test (P < 0.01) compared to vehicle-treated mice. Animal body weights also reduced significantly after 12-day treatment (P < 0.01). However, SbE, a very strong antioxidant extract, administered at 5–50 mg/kg (based on our previous studies without adverse events) for 12 days did not show any significant effects on blood glucose and body weight changes. No effects were shown when baicalein, an effective antioxidant constituent in SbE, was administered at 1–5 mg/kg. It appears that the anti-diabetic effect of American ginseng may not be linked to its antioxidant actions. The mechanisms of American ginseng's effects on reducing high blood glucose levels and body weight remain to be investigated in future experiments.