Clinically, chemotherapy is the mainstay in the treatment of multiple cancers. However, highly adaptable and activated survival signaling pathways of cancer cells readily emerge after long exposure to chemotherapeutics drugs, resulting in multi-drug resistance (MDR) and treatment failure. Recently, growing evidences indicate that the molecular action mechanisms of cancer MDR are closely associated with abnormalities in saccharides. In this review, saccharides affecting cancer MDR development are elaborated and analyzed in terms of aberrant aerobic glycolysis and its related enzymes, abnormal glycan structures and their associated enzymes, and glycoproteins. The reversal strategies including depletion of ATP, circumventing the original MDR pathway, activation by or inhibition of sugar-related enzymes, combination therapy with traditional cytotoxic agents, and direct modification on the sugar moiety, are ultimately proposed. It follows that abnormal saccharides have a significant effect on cancer MDR development, providing a new perspective for overcoming MDR and improving the outcome of chemotherapy. (C) 2021 Elsevier Masson SAS. All rights reserved.

An efficient multi-gram synthesis of bleomycin disaccharide has been developed, and its conjugate with 10-HCPT displayed obvious selectivity, clearly indicating the potential of bleomycin disaccharide in solving the targeted therapy of cytotoxic drugs.

Although heparan sulfate (HS) is widely implicated in numerous physiological and pathological processes, the biological function of nucleus HS remains underexplored, largely due to its complex structure and high hydrophilic property. To supplement these efforts, ideal vehicles are drawing attention as they combine attractive features including lipid solubility for penetrating cell membrane, high affinity binding to its target receptor, metabolic stability, and no cellular actions resulting in toxicity. Herein, we develop a convenient and promising strategy to prepare HS-FK506 conjugates for membrane transport and entry into nucleus, where click chemistry takes easily place between the exocyclic allyl group of a clinic drug FK506 and thiol as a handle incorporated into HS analogues. HS derivatives for constructing the conjugates were synthesized using a cutting-edge chemoenzymatic method. Meantime, [35S] labeled 3'-phosphoadenosine 5'-phosphosulfate (PAP35S) and [14C] glucuronic acid (Glc A) were adopted to label HS-FK506 conjugates, respectively, to evaluate their efficiency of nucleus entry, as a result, 14C Glc A was sensitive, effective and reliable whereas PAP35S gave rise to a mixture of labeled compounds, hampering the understanding of structure-function relationship of nucleus HS. Compared with the corresponding HS, the amount of HS-FK506 conjugates to translocate into nucleus from radioactive assay experiments sharply increased, e.g. tridecasaccharide-FK506 1d increased by approximate 10 folds, offering a simple and robust platform for enabling hydrophilic compounds including carbohydrates to translocate into nucleus and shedding light on their biological functions.

Components of 29 wild type tea single plants collected from Dayao Mountain, in Guangxi province, South China, were investigated. They included tea polyphenols, free amino acids, catechin, amino acid and alkaloid monomers etc. Genetic diversity and clustering analyses were conducted based on the main biochemical components. Meanwhile, genetic relationships among 6 wild type tea plants representing 3 tea populations of Daoyao Mountain with 15 tea varieties grown in Yunnan, Guangdong, Hunan, Fujian provinces were analyzed by random amplified polymorphic DNA. The results showed that wild type tea plants from Dayao Mountain were of rich genetic diversity. Furthermore, some tea germplasms with high quality, including high contents of amino acids, high epigallocatechin gallate, and high caffeine have been discovered. These wild type tea germplasms are of high values for further development values due to their geographical uniqueness.

广西大瑶山产茶历史悠久,从唐代起就有了产茶的记载.金秀县白牛茶以其能碎铜钱而被当做最为神奇的茶广为传颂.上世纪80年代,著名茶叶专家庄晚芳教授曾亲临白牛屯,并赋诗一首:“不少传闻流古今,西山白毫碧云天;铜钱嚼碎表优劣,石乳奇茗永世珍.”指的就是这一传说.同一时期,中国农科院茶叶研究所虞富莲研究员等专家对白牛茶树资源进行了考察,考察地点为金秀县罗香乡白牛屯,海拔为610m,并在白牛屯建立了原生境保护点(东经110°02 ′,北纬24°08 ′).2012年华南农业大学茶学系应金秀县政府邀请对白牛茶资源进行了详细的调查,其中白牛5号、6号为野生茶树,其余的为多年前瑶胞从山上移栽下来的.研究过程中发现白牛茶树不仅保存了部分原始特征,生化成分方面也比较特别,加工成红茶品质优异.

为探究大瑶山山脉野生茶树资源的生化成分特征,本研究测定了来自大瑶山29份茶树单株的19项生化指标.其中用分光光度法检测茶多酚、游离氨基酸、黄酮等含量,用高效液相色谱检测儿茶素、生物碱等组成,用氨基酸分析仪检测氨基酸组成.对主要生化成分进行遗传多样性分析和聚类分析,结果表明大瑶山野生茶具有丰富的遗传多样性和地域独特性,并从中筛选出了一批特异资源,如高氨基酸(＞4.00％)资源9份、高咖啡碱(＞5.00％)资源23份、高EGCG(＞10％)3份.

为了解广西金秀县野生茶资源的遗传进化轨迹以及品种特性,采用RAPD分子标记分析了该县4地8个野生茶品种与云南、广东、湖南和福建等周边省份的15个茶树品种的亲缘关系,在相似系数0.76处可将23份材料分成四大类群.采用SSR分子标记,选取条带易于辨认、稳定性好、多态性较高的5对引物组合(顺序依次为SSR1110、SSR685、SSR478、SSR496、SSR228)构建了广西金秀县4地22份野生茶资源的分子指纹图谱,从而可简单有效地判别具体品种(系).

2012年至今,广西金秀县与华南农业大学合作开展金秀野生茶树资源调查及研究项目,对金秀县境内原生野生茶的资源、种类及性状进行系统研究.普查工作组在了解、收集古茶树、古茶园相关信息、资料的基础上,深入金秀、长垌、罗香、大樟、六巷、忠良等8个乡镇及4个野生茶片区,实地察看野生茶生态环境、生长状况,测量、记录野生茶树数据,并进行了植物形态学、生物化学、分子生物学及主要生理活性研究,从野生茶树资源中选育了10余个优良新品系进行无性繁殖及品比实验.现从生长环境、资源特征以及产业开发等方面对金秀野生茶树资源进行概述.

ABSTRACT:Objective To study the content of elements in tea leaves under the influence of kinds and content in soil.Methods Content of 32 single elements including Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Cs, Ba, Hf, Ta, W, Tl, Pb, Bi, Ge, Mo, Ag, Cd, In, Sn, Sb, Se and 6 element compounds including MgO, P5O2, CaO, TiO2, MnO, Fe2O3-T in soil and leaching liquid of tea leaves of different grade of maturity from Shaoguan, Lianjiang, Meizhou and Chaozhou were detected by atomic absorption spectroscopy, after grinding, desulfurization, heating, dissolution and centrifugation.Results Correlation of elements between soil and leaching liquid of tea leaves of different grade of maturity had no significant difference, but there was a highly significant correlation between content of Zn, Ga, Sr and grade of maturity, and a significant correlation between content of Cu, Ba, Pb and grade of maturity. Elements inⅠ A,Ⅰ A,Ⅰ A,Ⅰ B,Ⅰ B,Ⅰ B,Ⅰ of fourth and fifth cycle in element periodic table were extremely selectively absorbed by tea plants. furthermore, Sr, P2O5, CaO and MnO were more easily absorbed by tea plants.ConclusionContent of elements in tea leaves is weakly influenced by that in soil, while greatly influenced by maturity.

Fuzhuan tea, Qingzhuan tea and Heizhuan tea are the most important kinds of dark tea. In this study, the aroma constituents of these three kinds of tea were extracted by simultaneous distillation extraction(SDE) and analyzed by gas chromatography-mass spectrometry(GC-MS), together with sensory evaluation. Results indicated that Fuzhuan tea was characterized as ba cterial aroma and(2E,4E)-hexa-2,4-dienal contributed to the aroma. Qingzhuan tea was rich in camphorwood aroma originated from cedrol(14.82%). The aroma of Heizhuan tea was plain due to its poor aroma contents(49.81%), which was consistent with the sensory evaluation.

中国的茶树栽培历史悠久,在长期的发展过程中,逐渐形成了四大茶区,即华南茶区,西南茶区,江南茶区和江北茶区.华南茶区位于中国南部,是中国最重要的茶区之一,主要包括广东、广西、海南、台湾等省份,茶树资源丰富,主要生产乌龙茶、红茶、绿茶、黑茶如六堡茶等.研究华南茶区主要茶叶加工技术不仅有利于提高华南茶区的茶叶品质,而且有利于提高华南茶区茶叶生产效益,对推动华南地区整体经济效益具有非常重要的作用.因此,本文对华南茶区主要茶叶种类及加工技术的相关性研究进行了综述,概述了华南茶区主要乌龙茶加工技术、红茶加工技术、绿茶加工技术、黑茶加工技术等,为后续研究华南茶区主要茶叶加工技术提供参考,以促进华南茶区茶叶产业健康、稳定、可持续发展.

金秀瑶族自治县成立于1952年,位于广西壮族自治区中部偏东的大瑶山主体山脉上,地处东经109° 50′-110°27′、北纬23°40′-24° 28′之间[1].大瑶山山脉从东北至西南方向纵贯,最高的圣堂山主峰1979米,为广西第五高峰.2012年10月至12月由华南农业大学茶学系和金秀瑶族自治县对该县野生茶树资源进行了考察,共收集资源47份,对野生茶形态学研究结果如下.

分子标记技术的不断发展为茶树资源与育种研究提供了新的途径。本文综述了RAPD、AFLP、ISSR、EST-SSR等分子标记在遗传多样性、亲缘关系和分类、分子鉴别、遗传图谱构建、辅助茶树育种等方面的研究进展。

广西金秀瑶族自治县茶树资源丰富，近年来茶叶产业发展迅猛。受县委、县政府委托，我们于2012年10月、11月先后两次深入该县大瑶山区进行了茶树资源调查、考察。

饮茶相传始于中国的神农氏时期,茶叶栽培作为中国传统古老的农业生产行业之一,公元六世纪时传入日本,在十七世纪传入欧洲,至今茶树种植生产已经遍布全球。茶叶成为了中国重要的经济作物,在中国的农业经济发展中发挥着重要作用。中国的茶树栽培历史发展非常悠久,在长期的发展过程中.逐渐形成了四大茶区,即华南茶区、西南茶区、江南茶区和江北茶区。其中,华南茶区茶叶生产在茶叶出口贸易以及社会经济发展中具有重要的地位。广东、广西、海南、台湾是华南茶区茶叶生产的主要地区,其地方茶树品种非常丰富,选育出多个国家级和省级良种。因此.有必要对华南茶区茶树品种特性及研究现状进行系统全面的了解,以便更好地促进华南茶区茶叶产业健康、稳定、可持续发展。

青砖茶是黑茶中的重要一种,具有悠久的历史和独特的品质,本文就其主要品质成分如水浸出物、茶多酚、茶氨酸、咖啡碱等的变化做综述,探讨其研究现状和前景。