咖啡因Na_2─EDTA对不同辐射敏感性作物质膜过氧化的维护效应     

宋道军  徐登益  万兆良  何首林 《西南大学学报(自然科学版)》1996,(3)

本文研究了咖啡因和Ｎａ２─ＥＤＴＡ辐照后处理对大豆和油菜７日龄幼苗质膜过氧化水平的生物学效应。结果表明，随着辐射剂量的增加，细胞膜透性、丙二醛、脯氨酸含量和过氧化物酶活性增大，而超氧化物歧化酶和过氧化氢酶则先增大而后降低。辐照后，大豆幼苗质膜过氧化程度高于油菜。咖啡因、ＥＤＴＡ后处理降低了两种作物的细胞膜过氧化水平和丙二醛含量，提高了脯氨酸含量和超氧化物歧化酶，过氧化氢酶和过氧化物酶的活性，减轻了辐射对细胞膜产生的损伤。咖啡因和ＥＤＴＡ后处理对油菜质膜的保护作用强于大豆，ＥＤＴＡ的作用效应强于咖啡因，咖啡因与ＥＤＴＡ复合作用协同效应不明显。  相似文献   

Biochemical diversity in the genus Coffea L.: chlorogenic acids,caffeine and mozambioside contents     

F. Anthony  M. N. Clifford  M. Noirot 《Genetic Resources and Crop Evolution》1993,40(2):61-70

Summary The extent and nature of biochemical diversity in green coffee beans was established by a large sampling of genus Coffea, representing nine species from the Guineo-Congolian region, nine species from east Africa and seven species from Madagascar. HPLC analyses were used to determine the contents of caffeine, chlorogenic acids and mozambioside. Data processed by principal component analyses showed the existence of two metabolic pathways. One leads to the synthesis of small quantities of chlorogenic acids (< 2.5% dmb) and caffeine ( < 0.3 % dmb) while the other leads to large concentrations of chlorogenic acids (> 4.5% dmb) and caffeine (> 0.4% dmb). Their distribution in the genus Coffea is discussed in relation to the biogeographic origin of the plant material.  相似文献   

嫁接对茶树新梢化学成分的影响   总被引：2，自引：2，他引：2  

梁月荣  陆建良  龚淑英  徐月荣  屠幼英 《茶叶》2001,27(1):39-40

以云南大叶种为砧木，乌牛早和浙农113为接穗进行嫁接试验，并与同期移栽的乌牛早和浙农113进行化学成分分析比较。结果表明，嫁接对该2品种的化学成分含量的明显影响，氨基酸和咖啡因含量增加；茶多酚和主要儿茶类素含量减少。  相似文献   

树脂AL-1 动态脱除茶叶咖啡碱的工艺研究     

王杰  吴晖 《广东农业科学》2012,39(4):84-86

选用10种大孔树脂分离脱除茶汤中的咖啡碱,以茶汤中咖啡碱、茶多酚的吸附率为指标,在静态吸附条件下筛选出分离咖啡碱效果较好的树脂AL-1。以洗脱率和吸附量为指标,考察了树脂AL-1的吸附性能和洗脱参数。结果表明,树脂AL-1对咖啡碱的吸附率最高,为98.58%。对于树脂AL-1吸附咖啡碱,当上样流速在0.75 mL/min、上样液pH值为5.2时,上样量最大,为11个柱体积;用50%的乙醇进行洗脱,洗脱剂用量为3个柱体积时,咖啡碱洗脱比较完全。  相似文献   

Effect of Chelated Vanadium Spray on Concentration of Vanadium and Organic Compounds in Tea Shoots     

In-Kwan Song  Tethvoleak Srey  Kyunguk Lee  Eun-Ui Oh  Jian-Liang Lu  Seung-Woon Song  Bong-Chan Kim  Young-Jae Lee  Kwan-Jeong Song 《茶叶》2013,(4):220-222

The study aimed to develop vanadium tea products and evaluated the potential of chelated vanadium （V） absorption by tea shoots and effect of vanadium accumulation on tea quality during the first crop season.Chelated V application with three times foliar sprays at 5 days intervals starting from 15 days before plucking showed a significant increase in V content of new young shoots,which was much effective at higher concentration.However,one or two times sprays had no increase in V content regardless of spray concentration compared to non-treated.Despite V accumulation in the treated at 3 to 9 times higher that of than the non-treated plants,there were no significant changes in contents of total amino acids,theanine,caffeine,total polyphenols,crude fiber,and cathechins between the treated and the non-treated.  相似文献   

Purine Alkaloids and their Metabolism in Camellia Sinensis and Related Species简     

Liu C  Liang YR  Zheng XQ 《茶叶》2013,(4):240-246

Caffeine,theobromine and theophylline are the major purine alkaloids found in Camellia sinensis.Theacrine was detected in a special Chinese tea plant named kucha （Camellia kucha）.With tracer experiments,the metabolism pathway of these purine alkaloids has mostly been explored.The isolation and cloning of the genes encoding enzymes in the related pathway made it possible to develop methods to control caffeine level in tea products via transgenic technique.Further study on the kucha species would be helpful to obtain materials for processing naturally caffeine-less tea.However,there is still a long way to go in this direction such as sensory improvement of products prepared using leaves of kucha.  相似文献   

茶树咖啡碱合成酶基因稀有等位变异TCS1g的筛选、克隆及功能     

刘玉飞  金基强  姚明哲  陈亮 《中国农业科学》2019,52(10):1772-1783

【目的】茶树咖啡碱合成酶1（TCS1）是山茶属（Camellia）茶组植物咖啡碱合成的关键酶,TCS1具有丰富的等位变异。从我国丰富的茶树种质资源中发掘TCS1稀有等位变异并研究其功能,深入解析茶树咖啡碱合成机制,为低咖啡碱育种提供新的基因资源。【方法】利用特异引物TCS1P InDel F/R对673份茶树资源中的TCS1等位变异进行鉴定;使用引物TCS1cDNAF/R,从含有新稀有等位变异的茶树资源中克隆基因的cDNA全长序列;利用生物信息学、实时荧光定量PCR（qRT-PCR）和原核表达等方法研究新发现稀有等位基因的功能。【结果】在部分大理茶（C. taliensis）资源中鉴定到一个新的TCS1稀有等位变异,命名为TCS1g。从大理茶资源‘龙陵17’（LL17,含有的TCS1等位变异为TCS1a和TCS1g）中克隆了TCS1g。TCS1g的编码区序列全长为1 098 bp,编码365个氨基酸,编码蛋白的分子量和理论等电点分别为40.9 kD和5.1。序列比对结果表明,TCS1g与TCS1a、TCS1b、TCS1c、TCS1d、TCS1e、TCS1f的相似度在94.1%—99.2%;与具有可可碱合成酶活性（TS）的TCS1b和TCS1c编码蛋白序列相似度均大于96.7%,而与同时具有TS和咖啡碱合成酶（CS）活性的TCS1a、TCS1d、TCS1e、TCS1f相似度都小于95.4%,且TCS1g第221位氨基酸残基与TCS1b、TCS1c同为组氨酸（His）,而TCS1a、TCS1d、TCS1e、TCS1f为精氨酸（Arg）。第221位氨基酸残基位于TCS1g蛋白活性中心,该位点的突变（His突变为Arg）,可以导致TCS1g的等电点（5.05变为5.06）和亲水性（-0.119变为-0.123）发生改变。此外,5′上游调控区域的比对结果显示TCS1g、TCS1b、TCS1c起始密码子（ATG）比TCS1a、TCS1d、TCS1e、TCS1f延后了15 bp。原核表达发现TCS1g具有TS活性,活性为44.3 pkat/mg,但未检测到CS活性。qRT-PCR的结果表明LL17中等位变异TCS1g有表达。LL17的咖啡碱和可可碱的含量分别为40.3 mg·g ^-1和5.4 mg·g ^-1。 【结论】鉴定并克隆了一个新的TCS1稀有等位变异TCS1g,其在LL17中具有一定的表达水平,且其表达蛋白具有TS活性,而未检测到CS活性;推测决定TCS1g仅具有TS活性的关键位点是第221位氨基酸残基。  相似文献   

Genetic parameters of several biochemical compounds from green coffee, Coffea canephora     

C. Montagnon    B. Guyot    C. Cilas  T. Leroy 《Plant Breeding》1998,117(6):576-578

A factorial crossing scheme of Cofflea canephora (two parents from the Congolese group crossed to 14 parents of the Guinean group) was used to evaluate genetic parameters of several biochemical compounds, bean weight and crop outturn (ration of dry bean weight 10 fresh berry weight). For most characters studied, additive genetic effects were preponderant. Narrow-sense heritability was high for caffeine content (h²_ns= 0.80), fat matter content (h²_ns, = 0.74), bean weight (h²_ns= 0.73) and crop outturn (h²_ns= 1). It was intermediate for trigonelline (h²_ns= 0.38) and chlorogenic acid (h²_ns= 0.36) content. Only sucrose content had a low narrow-sense heritability (h²_ns=0.11). There were few genetic and enviromnental correlations, Consequences for breeding, in relation to coffee drinking quality, are discussed.  相似文献   

茶叶咖啡碱近红外光谱模型简化方法   总被引：9，自引：4，他引：5  

耿响  陈斌  叶静  颜辉  胡永光 《农业工程学报》2009,25(10):345-349

该文以茶叶为研究对象,以近红外光谱分析技术快速检测茶叶中的咖啡碱含量为目的,采用一种小波包分析-移动窗口偏最小二乘法（WPA-MWPLS）的处理光谱数据方法,即利用小波包精细的多层分解功能扣除背景、降低噪声的影响,利用移动窗口偏最小二乘法（MWPLS）挑选与茶叶中咖啡碱相关性较大的波数区间使用偏最小二乘法建立校正模型。与只经过Savitzky–Golay预处理后直接利用PLS所建模型相比,采用小波包分析-移动窗口偏最小二乘法使得预测相关系数R由0.9170提高到了0.9625;预测均方差RESEP由0.3071下降为0.2463。该结果表明：该方法具有预处理简单、优选参数和建模变量少等特点,能在很大程度上简化建模过程、提高建模和分析速度。  相似文献   

Chemical profiles and identification of key compound caffeine in marine-derived traditional Chinese medicine Ostreae concha     

X Yang  SL Zhou  AC Ma  HT Xu  HS Guan  HB Liu 《Marine drugs》2012,10(5):1180-1191

To compare the chemical differences between the medicinal and cultured oyster shells, their chemical profiles were investigated. Using the ultra performance liquid chromatography-electron spraying ionization-mass spectrometry (UPLC-ESI-MS), combined with principal component analysis (PCA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA), the discrimination of the chemical characteristics among the medicinal and cultured oyster shells was established. Moreover, the chemometric analysis revealed some potential key compounds. After a large-scale extraction and isolation, one target key compound was unambiguously identified as caffeine based on extensive spectroscopic data analysis (1D and 2D NMR, MS, and UV) and comparison with literature data.  相似文献