表没食子儿茶素没食子酸酯的化学修饰及生物活性研究进展

表没食子儿茶素没食子酸酯(epigallocatechin gallate, EGCG)是茶叶中的一种重要儿茶素,具有良好的生物活性,但口服生物利用度低、脂溶性及稳定性差等缺点使其在功能性健康产品开发中的应用受到限制。研究发现,通过醚化、酯化和糖苷化等化学修饰方法,在EGCG结构中引入烷基、酰基、糖基等基团可得到不同EGCG衍生物,显著改善EGCG的理化性质,并特异性增强EGCG的抗氧化、抗炎、抗病毒、抗衰老、抗癌等生物活性。醚化修饰的操作简便,但产物复杂、不利于后续的分离纯化;酯化修饰的研究多集中在小分子试剂上;糖苷化修饰的合成技术难度较高,但是该修饰方法可定向制备目标产物。本文整理近几年的国内外相关文献,对EGCG化学修饰的常见方法及EGCG衍生物的活性研究进行了系统的总结,为EGCG的构效关系研究及开发EGCG类功能性健康产品提供参考。     

一个基于纠错码和DCT变换的盲水印算法

提出了一个基于纠错码和DCT变换的图像盲水印算法,该算法利用图像置乱技术和纠错码方法生成水印序列。对不用纠错码、用汉明码和用BCH码的三种水印方案进行了仿真,结果表明利用纠错码的水印方案具有更好的鲁棒性。     

Handling partial truth on type-2 similarity-based reasoning

Representation and manipulation of the vague concepts of partially true knowledge in the development of machine intelligence is a wide and challenging field of study. How to extract of approximate facts from vague and partially true statements has drawn significant attention from researchers in the fuzzy information processing. Furthermore, handling uncertainty from this incomplete information has its own necessity. This study theoretically examines a formal method for representing and manipulating partially true knowledge. This method is based on the similarity measure of type-2 fuzzy sets, which are directly used to handle rule uncertainties that type-1 fuzzy sets cannot. The proposed type-2 similarity-based reasoning method is theoretically defined and discussed herein, and the reasoning results are applied to show the usefulness with the comparison of the general fuzzy sets.     

宾川葡萄籽原花青素纯化及对HepG2细胞增殖的影响

目的:研究云南大理宾川葡萄籽原花青素纯化及对肝癌HepG2细胞增殖的影响.方法:考察了上样液质量浓度、pH、流速、乙醇体积分数等对葡萄籽原花青素吸附及解析的影响,研究AB-8型大孔吸附树脂纯化云南大理宾川葡萄籽原花青素的条件.将纯化过程中乙醇梯度洗脱得到的不同极性葡萄籽原花青素作用于HepG2细胞,采用CCK8法检测不...     

A Comparative Analysis of the Chloroplast Genomes of Four Salvia Medicinal Plants

Herbgenomics is an emerging field of traditional Chinese medicine (TCM) research and development. By combining TCM research with genomics, herbgenomics can help to establish the scientific validity of TCM and bring it into wider usage within the field of medicine. Salvia Linn. (S. Linn.) is a large genus of Labiatae that includes important medicinal plants. In this herbgenomics study, the complete chloroplast (cp) genomes of two Salvia spp.—namely, S. przewalskii and S. bulleyana, which are used as a surrogate for S. miltiorrhiza—were sequenced and compared with those of two other reported Salvia spp.—namely, S. miltiorrhiza and S. japonica. The genome organization, gene number, type, and repeat sequences were compared. The annotation results showed that both Salvia plants contain 114 unique genes, including 80 protein-coding, 30 transfer RNA (tRNA), and four ribosomal RNA (rRNA) genes. Repeat sequence analysis revealed 21 forward and 22 palindromic sequences in both Salvia cp genomes, and 17 and 21 tandem repeats in S. przewalskii and S. bulleyana, respectively. A synteny comparison of the Salvia spp. cp genomes showed a high degree of sequence similarity in the coding regions and a relatively high divergence of the intergenic spacers. Pairwise alignment and single-nucleotide polymorphism (SNP) analyses found some candidate fragments to identify Salvia spp., such as the intergenic region of the trnV–ndhC, trnQ–rps16, atpI–atpH, psbA–ycf3, ycf1, rpoC2, ndhF, matK, rpoB, rpoA, and accD genes. All of the results—including the repeat sequences and SNP sites, the inverted repeat (IR) region border, and the phylogenetic analysis—showed that S. przewalskii and S. bulleyana are extremely similar from a genetic standpoint. The cp genome sequences of the two Salvia spp. reported here will pave the way for breeding, species identification, phylogenetic evolution, and cp genetic engineering studies of Salvia medicinal plants.     

芸豆提取物α-淀粉酶抑制剂对SD大鼠的减肥效果研究

探讨从云南白芸豆所提取的α-淀粉酶抑制剂对SD大鼠降脂减肥作用。按中国卫生部减肥功能检验规范方法第2003年版[1]进行相应实验。采用高(352mg/kg)、中(141mg/kg)、低(70mg/kg)3个剂量组的芸豆提取物α-淀粉酶抑制剂连续灌胃45d后均对降低SD大鼠体重、睾丸周围脂肪垫质量及大鼠血液总胆固醇有显著效果(P<0.05)。芸豆α-淀粉酶抑制剂对降低肥胖大鼠体重、内脏脂肪及总胆固醇有显著作用。     

以酸枣仁、茯苓为主的复方固体饮料改善睡眠的作用研究

目的 探讨一种以酸枣仁、茯苓为主的复方固体饮料改善睡眠作用,初步探究改善睡眠的作用机制。方法：选取120只SPF级健康雄性Balb/c小鼠,随机进行分组,每组10只,每天经口灌胃给予阴性对照组(生理盐水)、固体饮料低、中、高3个剂量(6.5 g/kg、13 g/kg、19.5 g/kg),连续灌胃30 d 后,进行直接睡眠实验、延长戊巴比妥钠睡眠时间实验、戊巴比妥钠阈下剂量催眠实验、巴比妥钠睡眠潜伏期实验;使用酶联免疫吸附试验法(enzyme linked immunosorbent assay,Elisa)法检测脑组织中5-羟色胺(5-hydroxytryptamine,5-HT)、多巴胺(dopamine,DA)、γ-氨基丁酸(γ-aminobutyric acid,GABA)的含量。结果：复方固体饮料无直接睡眠作用;与阴性对照组相比,复方固体饮料低、中、高剂量小鼠睡眠时间分别延长了42.63%、54.09%、53.55%,均具有统计学差异(P＜0.001);各剂量组小鼠30 min内小鼠阈下剂量催眠实验均为阳性,小鼠的睡眠发生率增加,差异具有统计学意义(P＜0.001);各剂量组小鼠巴比妥钠睡眠潜伏期时间显著缩短(P＜0.001),差异具有统计学意义;复方固体饮料低剂量组能显著提高小鼠脑内5-HT和GABA含量显著升高(P＜0.01);复方固体饮料中、高剂量组能使小鼠脑内5-HT、DA和GABA酸含量显著升高(P＜0.001),差异具有统计学意义。结论：复方固体饮料片具有明显的促睡眠作用,与戊巴比妥钠的协同作用较强,可能与脑组织中GABA、5-HT、DA水平的提高有关。