关键词：
Theanine;Caenorhabditis elegans;Stress resistance;Heat shock protein
摘要：
The beneficial effects of theanine in tea are reported on many aspects. Here we report that theanine can extend nematode Caenorhabditis elegans lifespan under stress. Theanine (100 mg/mL) significantly increased the mean longevity of C. elegans by 12.8% and 21.3% under heat stress and oxidative stress, respectively. However, theanine treatment did not increase survival of C. elegans under normal culture condition. Further studies showed that theanine mediated lifespan extension under heat stress was involved in heat shock protein-16.2 (HSP-16.2) up-regulating expression. (C) 2012 Elsevier Ltd. All rights reserved.
摘要：
Although much effort has been made in the field of membrane proteomics, the analysis of membrane proteins particularly integral membrane proteins with poor water solubility still presents a great challenge. In this paper, 2% SDS was used to extract membrane proteins and experimental conditions for the application of acetone precipitation method to the cleanup of SDS-solubilized membrane protein sample were optimized. For improving the re-dissolution and trypsinolysis of acetone-precipitated proteins, several commonly used additives, urea, methanol and sodium deoxycholate (SDC), were employed and compared. The results showed that, when the pre-cooled acetone-to-sample ratio was 6:1 (v/v) with one additional washing step, residual SDS in the protein sample could be lowered to below 0.01% and more than 90% of the proteins were precipitated and therefore recovered. 1% SDC-containing buffer could improve the re-dissolution and digestion of the acetone precipitated proteins more efficiently than the others. Using the combinative sample preparation strategy developed, 398 proteins were identified from the rat liver membrane-enriched fraction, including 188 membrane proteins. Compared with other three representative solution-based sample preparation methods commonly used in membrane proteomics, the newly developed combinative strategy increased the number of identified total proteins and membrane proteins on average by 29.2% and 28.5%, respectively. This combinative strategy was demonstrated to be easily operated at low cost and suitable for the analysis of membrane proteins varying in type and sample volume, etc. (C) 2012 Published by Elsevier B.V.
摘要：
In order to discover the formation mechanism of carotenoid derived aroma, which has been wildly used on protection of crop against insect attacks, the full-length cDNA of an Artemisia annua carotenoid cleavage dioxygenase (AaCCD1) was cloned by rapid amplification of cDNA ends. The function of AaCCD1 was characterized by expression of AaCCD1 in a strain of E. coli accumulating carotenoids and enzyme assay in vitro. The completed open read frame of AaCCD1 was 1629 bp and it encoded a 542-amino acid protein with a 77% amino acid identity to Arabidopsis thaliana CCD1, a predicted molecular mass of 61.04 kDa and a pI of 5.8. AaCCD1 efficiently cleaves carotenoids and regulate the formation of terpenoid compounds. This is the first time to report the cloning and identification of carotenoid cleavage dioxygenase from Atemisia annua, which will play a great role on understanding the regulation of volatile compounds.
作者机构：
1. 长沙医学院公共卫生系;2. 国家植物功能成分利用工程技术研究中心;3. 湖南农业大学园艺园林学院植物资源工程系;[刘仲华; 张盛] National Res. Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha 410128, China, Department of Botanical Resources Engineering, College of Horticulture and Gardening, Hunan Agricultural University, Changsha 410128, China;[刘慧] Public Health College, Changsha Medical University, Changsha 410219, China, National Res. Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha 410128, China
通讯机构：
[Zhang, S.] N;National Res. Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha 410128, China
摘要：
It is still a major challenge to simultaneously isolate artemisinin and its precursors, especially dihydroartemisinic acid and artemisinic acid, from herbal Artemisia annua. A rapid, economical and automatical chromatographic separation process to isolate and purify artemisinin, dihydroartemisinic acid and artemisinic acid at the same time on a preparative scale was developed. The procedure included solvent extraction of ground Artemisia annua leaves by refluxing and purification of crude extract by preparative reverse-phase high-performance liquid chromatography (RP-HPLC). Fractions containing artemisinin and its precursors were collected and identified by gas chromatography and mass spectrometry. High purity of artemisinin, dihydroartemisinic acid and artemisinic acid was obtained by preparative HPLC with a C18 column and 60% acetonitrile in water as the mobile phase. The techniques described here are useful tools for the preparative-scale isolation of artemisinin and its precursors in a fast, cost-effective and environmental friendly manner. Copyright (C) 2011 John Wiley & Sons, Ltd.
作者机构：
[Kunbo Wang; Fang Liu; Zhonghua Liu; Jian-an Huang; Yong Lin; Yushun Gong] National Research Center of Engineering & Technology for Utilization of Botanical Functional Ingredients,Key Laboratory of Tea Science of Ministry of Education,Hunan Agricultural University,Changsha,Hunan,410128,China
会议名称：
第七届国际逆流色谱会议(The 7th International Conference on Countercurrent Chromatography)(CCC2012)
会议时间：
2012-8-6
会议地点：
杭州
会议主办单位：
浙江工商大学
会议论文集名称：
第七届国际逆流色谱会议(The 7th International Conference on Countercurrent Chromatography)(CCC2012)论文集
摘要：
The characteristic feature of oolong tea components is that it contains numerous kinds of polymerized-polyphenols,which are derived from tea catechins by polyphenol oxidases or by heating process,which is called semifermented process.Oolong tea polymerized-polyphenols,EGCG,gallocatechin gallate and caffeine,which are the major compounds of oolong tea extract,were examined (1).Isolation of tea polyphenols or catechins has been based on chromatography on (semi-) preparative HPLC and sephadex LH-20 (2,3).The procedures are times consuming and tedious.Thereafter,it is ideal for the separation of tea polyphenols or catechins by HSCCC (4-6).High-speed countercurrent chromatography (HSCCC) has been applied for the separation of oolong tea polyphenols.The HSCCC run was carried out with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water-acetic acid (1:5:1:5:0.25,v/v) by eluting the lower aqueous phase at 2 ml/min at 700 rpm.The results indicated that catechins including epigallocatechin gallate,gallocatechin gallate and epicatechin gallate were isolated from the aqueous extract of oolong tea (Fig.1).Fujian Tieguanyin,Dahongpao,Guangdong Fenghuang Dancong and Taiwanese oolong have similar HSCCC profiles.Solvent system: hexane–ethyl acetate–methanol–water–acetic acid (1/5/1/5/0.25,v/v); mobile phase: lower aqueous phase; low-rate: 2 ml/min; column volume: 243.0 ml; sample size: 40 mg; retention of stationary phase: 66.3%; 1,2,4: unknown; 3: EGCG; 5: GCG; 6: ECG.
摘要：
Two new cinnamic acids, 2-O-caffeoyl-3-O-isoferuloyltartaric (3), and 2, 3-di-O-isoferuloyltartaric acid (5), along with three known caffeic acids, cichoric acid (1), 2-O-caffeoyl-3-O-feruloyltartaric acid (2) and 2-O-caffeoyl-3-O-p-coumaroyltartaric acid (4), have been successfully isolated and purified from Echinacea purpurea. In this study, we investigated an efficient method for the preparative isolation and purification of cinnamic acids from E. purpurea by high-speed counter-current chromatography (HSCCC). The separation was performed using a two-phase solvent composed of n-hexane-ethyl-acetatemethanol- 0.5% aqueous acetic acid (1:3:1:4, v/v). The upper phase was used as the stationary phase and the lower phase as the mobile phase, with a flow rate of 1.6 mL/min. From 250 mg of crude extracts, 65.1 mg of 1, 8.3 mg of 2, 4.0 mg of 3, 4.5 mg of 4, and 4.3 mg of 5 were isolated in one-step, with purities of 98.5%, 97.7%, 94.6%, 94.3%, and 98.6%, respectively, as evaluated by HPLC-DAD. The chemical structures were identified by electro spray ionization mass spectrometry (ESI-MS) and one- and two-dimensional NMR spectra. HSCCC was very efficient for the separation and purification of the cinnamic acids from E. purpurea.
