云南不同产地及品种小粒种咖啡豆化学及卫生指标比较

【目的】云南是生态环境最多样的省份,因受生长环境的影响各地出产的咖啡豆品质不同,研究云南不同产地咖啡豆的品质特点可为其合理种植及利用提供指导。【方法】以云南保山和普洱2个主产区的不同海拔、不同品种小粒种咖啡豆样品共50份为材料,对其主要品质指标(包括水分、灰分、水浸出物、咖啡因、总糖、蛋白质、粗脂肪、粗纤维和重金属砷、铅、镉的含量共11项)进行比较研究。【结果】2个产地咖啡豆的主要化学指标(水浸出物、总糖、粗脂肪、粗纤维含量)和卫生指标(重金属砷、铅、镉含量)均达到行业标准NY/T 604-2006和地方标准DB53/T 154.5-2006,而且水浸出物含量、总糖含量、粗脂肪含量和粗纤维含量显著高于地方标准;在品质特点方面,保山出产的卡蒂姆咖啡豆水分含量较低而水浸出物、总糖和粗脂肪含量较高,普洱出产的卡蒂姆咖啡豆灰分、咖啡因和粗纤维含量较低而蛋白质含量较高;咖啡豆的品质因品种和产地而不同,而海拔与除蛋白质之外的其余品质指标相关均不显著。【结论】云南保山和普洱所产的咖啡豆均为优质咖啡豆,品质有异但各具特色,各地应根据品种特性和环境条件合理进行选择和开发利用。

Expression of CTB-human Insulin(BA) Fusion Protein in Gynostemma Pentapyhllum Makino Callus Cells and Its Hypoglycemic Effect in Mice

The plant expression vector of choleratoxin B subunit（CTB）-human insulin（BA） fusion protein pBI121/（CTB-BA） was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express CTB-human insulin fusion protein was constructed and its hypoglycemic effect was evaluated in mice. The plant expression vector pBl 121/（CTB-BA） was digested with both BamI and SacI. Agrobacterium tumerfaciens strain LBA4404 was transformed with previously constructed recombinant plasmid pBI121/（CTB-BA） via the freeze thawing method, then CTB-BA gene was integrated to G Pentapyhllum Makino callus cells by co-culturing the cells with the transformed LBA4404 strain. The transformed G Pentapyhllum Makino callus cells were identified by DNA sequence assey and RT-PCR. The expressed product was identified by western-blot and its amount was tested by ELISA kit and its blood sugar decreasing effect was tested in mice. The sequences of synthetic CTB and human insulin genes（BA） were completely identical to those designed. Restriction map proved that the length of gene fragment in- serted into expression vector pBI121 was consistent with that expected. The sequence of genomic DNA of expressed product was completely identical to that designed. The result of RT-PCR was consistent with that expected. The expressed product showed a specific band with a relative molecular mass of 17000 by Western-blot. The human insulin expression amount was 6.03 μIU/mL according to the ELISA result. The animal test showed that only the G Pentapyhllum Makino callus cell line itself showed activity in decreasing the blood sugar of mice, however, the activity of the transformed G Pentapyhllum Makino callus cells was much higher, The plant expression vector pBI121/（CTB-BA） was constructed and expressed in the G Pentapyhllum Makino callus cells successfully for the first time. The trans- formed G Pentapyhllum Makino callus cells showed high activity in decreasing the blood sugar of mice. This study developed a new way for the development of oral administration insulin.

Translational Enhancer of Tobacco mosaic virus Enhancing Expression of Hepatitis B Surface Antigen in Transgenic Panax ginseng C. A. Meyer Callus

The 5＇-nontranslated leader（omega sequence） of Tobacco mosaic virus（TMV） was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen（HBsAg） gene in transgenic ginseng callus cultures. The adr subtype HBsAg gene was placed under the control of the Cauliflower mosaic virus（CaMV） 35S promoter linking to the TMV leader sequence. The antisense omega sequence was used in a control construct. The resulting constructs cloned in the binary vector pBI121 were used to transform the ginseng callus tissue via the Agrobacterium-mediated procedure. The integration and expression of the HBsAg gene were evaluated by PCR and western blot, respectively. Enzyme-linked immunoassays（ELISA） using a monoclonal antibody directed against human serum-derived HBsAg revealed a three to four-fold enhanced expression of HBsAg in ginseng cells conferred by the TMV omega element.

Expression of Hepatitis B Surface Antigen Gene in Ginseng Cells

The recombinant plasmid pBIBSa containing the HBsAg DNA fragment was transferred into Agrobacterium tumefaciens strain LBA4404 directly. Ginseng cells were transfected with A. tumefaciens carrying pBIBSa and the ginseng cell lines carrying HBsAg-S gene were obtained. The presence of target gene in the transfect cells was confirmed by PCR and RT-PCR. A clear band at the site of 700 bp was observed by agarose electrophoresis analysis of the samples containing the target gene. HBsAg expressed by the transgenic ginseng cells was detected by Western blot. Maximum expression levels of 184 ng HBsAg/g FW and 0. 009% of the total soluble proteins were observed by ELISA. HBsAg in ginseng cells was located both on the cell membrane and in the nuclei.

Caffeine is responsible for the bloodglucose-lowering effects of green tea and Puer tea extractsin BALB/c mice

The present study was designed to determine the effects of Puer tea and green tea on blood glucose level. Male BALB/c mice were administered green tea extract(GTE) or Puer tea extract(PTE), either intragastrically or in their drinking water. The major components of these teas are epigallocatechin gallate(EGCG) and caffeine, respectively. Blood glucose measurement results showed that mice fed intragastrically or mice that drank GTE, PTE or caffeine showed significantly lower blood glucose levels compared to the control group. However, EGCG exhibited no influence on the blood glucose levels. When caffeine was eliminated from the GTE and PTE, the effect on the blood glucose levels was abolished, but the effect was recovered when caffeine was re-introduced into the extracts. Evaluation of hematological and biochemical indices at the time of the greatest caffeine-induced decrease in blood glucose levels showed that the effect of caffeine was specific. Microarray analyses were performed in 3T3-L1 preadipocytes and mature adipocytes treated with 0.1 mg·m L-1 caffeine to identify factors that might be involved in the mechanisms underlying these effects. The results showed that few genes were changed after caffeine treatment in adipocytes, and of them only phospholipid transfer protein(PLTP) may be ralated to blood glucose. In conclusion, this study indicates that caffeine may be the key constituent of tea that decreases blood glucose levels, and it may be used to treat type 2 diabetes.