植物内生真菌: 获取抗癌药物白藜芦醇的新途径

白藜芦醇(Resveratrol)是一种含有芪类结构的非黄酮类多酚化合物,以游离态和糖苷结合态(白藜芦醇苷)两种形式存在于植物中,是植物受到病菌感染或环境恶化时产生的应激产物.常见的含有白藜芦醇(苷)的植物有葡萄、虎杖、花生、桑椹、藜芦、决明等.近年的研究表明,白藜芦醇(苷)具有显著的抗炎、抗氧化、神经保护和心血管保护等作用,可预防和治疗多种疾病,有较高的使用安全性,已成为抑制和治疗组织癌变和肿瘤发生的最有前途的药物之一.     

红葡萄酒含白藜芦醇适量饮用可防病健身

Biochemical and Biophysical Research Communications 1999年254卷3期报道:1992年Siemann等在红葡萄酒中发现白藜芦醇(3,5,4′-三羟芪),并认为它可能具有临床意义.与此同时,流行病学调查表明,适量饮用红葡萄酒可防治心血管病. 此后证明,红葡萄酒中可保护心血管的化合物就是白藜芦醇.原因是白藜芦醇分子具有抗氧化作用,可以减轻低密度脂蛋白(LDL)的氧化,从而防止动脉粥样硬化的产生.无独有偶,R uf等于1995年发现白藜芦醇可抑制与动脉粥样硬化有关的血小板凝集.     

白藜芦醇心血管保护作用研究进展

白藜芦醇(resveratrol)是广泛存在于水果、中药和葡萄酒中的一种植物抗毒素,具有多种生物学作用。本文主要从白藜芦醇减少心肌缺血-再灌注损伤、舒张血管、抗动脉粥样硬化等方面对其心血管保护作用及其机制作一综述。     

白藜芦醇合酶的研究进展

白藜芦醇是一种重要的植物抗毒素,具有多种医疗保健作用,因此其应用前景 非常广泛,已引起多方关注。白藜芦醇合酶是白藜芦醇生物合成途径中的关键酶之一,它催化1分子4-香豆酰辅酶A和3分子丙二酰辅酶A反应合成白藜芦醇,它是白藜芦醇生物合成中惟一必需的酶,关于它的研究已广泛开展起来。本文综述了白藜芦醇的药理活性、白藜芦醇合 酶的酶学性质、诱导途径和机制以及分子生物学方面的研究进展。     

白藜芦醇的肝脏药理作用

白藜芦醇（Resveratrol,Res）是一种自然产生的含有芪类结构非黄酮类多酚化合物,主要在红葡萄酒、花生中发现。在过去几年的研究中发现白藜芦醇具有抗肿瘤、抗氧化、抗炎、降血糖、止痛、平喘等作用。有报道表明,Res对于青光眼、胰腺炎、骨关节炎等疾病具有保护作用。它可以防止和治疗心血管疾病,同时对肝脏亦有保护性作用。以下就近年来对白藜芦醇关于肝脏的药理作用的研究进展作一综述。本文主要从抗肝损伤、抗肝纤维化、抗肝癌三方面对白藜芦醇对肝脏的保护作用进行阐述。     

快速溶剂萃取提取白藜芦醇和白藜芦醇苷工艺的响应面优化

以白藜芦醇和白藜芦醇苷的总量为指标,考察了超声、加热回流、快速溶剂萃取(ASE)三种提取方法对青海栽培何首乌中白藜芦醇和白藜芦醇苷提取效果的影响,通过单因素实验和响应面法优化ASE的提取条件,在单因素实验基础上筛选出乙醇浓度、提取温度、提取时间三个主要因素。结果表明,ASE在提取效果上优于其他两种方法,通过响应面分析得出最佳组合条件为:乙醇浓度51%,提取温度96℃、提取时间16 min。快速溶剂萃取法简单、快捷、高效,适用于何首乌中白藜芦醇和白藜芦醇苷的提取。     

薄层层析-紫外分光光度法测定葡萄果皮中白藜芦醇及白藜芦醇苷

建立了葡萄果皮中反式白藜芦醇及反式白藜芦醇苷含量的薄层层析-紫外分光光度测定法.以甲醇提取目标组分,以高效硅胶GF254为固定相,甲苯:乙酸乙酯:甲酸(5:4:1)为展开剂,对反式白藜芦醇及反式白藜芦醇苷进行分离纯化.并用紫外分光光度法进行定量,波长为306 nm.结果表明,该方法测定反式白藜芦醇及反式白藜芦醇苷含量的线性关系良好,相关系数为0.9997;平均回收率为98.12%、97.23%;方法的精密度较高.并用该方法测定了酿酒红葡萄品种蛇龙珠不同生长时期的反式白藜芦醇和反式白藜芦醇苷含量.     

白藜芦醇在糖尿病治疗中的作用

白藜芦醇(resveratrol)是一种从植物中提取的多酚类化合物,它广泛存在于葡萄等植物中。白藜芦醇具有广泛的生物学活性,抗氧化、抗癌和调节代谢等作用。白藜芦醇在治疗糖尿病(diabetes mellitus, DM)中可有效改善胰岛β细胞功能及刺激胰岛素的分泌。白藜芦醇的作用机制较为复杂,现就白藜芦醇在DM治疗中的作用及机制作一概述。     

大肠杆菌中从头合成白藜芦醇途径的设计及优化

白藜芦醇是一种极具药用价值的植物源芪类化合物。为了在E.coli实现白藜芦醇的从头合成,构建了由酪氨酸解氨酶(TAL),香豆酸-CoA合成酶(4CL)和白藜芦醇合成酶(STS)组成的非天然合成途径。经3天发酵后,白藜芦醇产量仅为2.67 mg/L,而其中间体香豆酸的积累达到了95.64 mg/L。为了进一步改善异源途径的效率,对4CL和STS模块采取融合表达、高拷贝表达及启动子工程改造的策略,最终使白藜芦醇产量提高到了9.6倍,达到了25.76 mg/L,同时香豆酸的积累减少到了20.38 mg/L。这些研究结果为更高效白藜芦醇从头合成工程菌的构建及最终实现白藜芦醇的微生物大规模生产奠定了基础。     

白藜芦醇代谢物的研究进展

白藜芦醇是一些植物在受到生物和非生物胁迫时产生的一种植物抗毒素.它在植物体内会迅速被代谢而生产紫檀芪、云杉新苷、viniferins等代谢物.这些代谢物与白藜芦醇一样具有抗菌、消炎、抗血小板凝集、防止细胞癌变等一系列的生物活性,且有些代谢物的选择性、稳定性远远大于白藜芦醇.本文对白藜芦醇代谢物中几种主要代谢物的合成途径、生物活性、代谢调控、检测方法等进行了综述.     

Chlorophyll isolation,structure and function: major landmarks of the early history of research in the Russian Empire and the Soviet Union

This paper covers major events of the early history of chlorophyll research in the Russian Empire and the Soviet Union from 1771 until 1952, when the modern period of studies on photosynthesis began in full swing. Short biographical sketches of key scientists, reviews of their major research contributions and some selected photographs are included. This revised version was published online in August 2006 with corrections to the Cover Date.     

巴戟天根的结构及其与蒽醌类化合物积累的关系

应用石蜡切片法、荧光显微镜和紫外分光光度法,对不同年生巴戟天根组织结构的变化进行了观察、对蒽醌类化合物在根中的分布场所及其积累动态进行了研究。结果表明:巴戟天根的结构类似一般多年生草本植物,薄壁细胞是巴戟天根中蒽醌类化合物的分布储存场所,蒽醌类化合物含量随着根生长年限的增加而增加。由以上研究总结出巴戟天以四年或四年以上采收为好,并以根皮厚、木心细者为上品。     

Protein intake regulation in the weanling rat: Effects of additions of lysine,arginine and ammonia on the selection of gluten and energy

The effects of adding lysine, arginine and ammonia to gluten on the self-selection of protein and energy by the weanling rat simultaneously offered a choice of two diets differing only in gluten concentration (15 and 55%) were tested. Previous studies have shown that while lysine (6 g/100 g) additions to gluten decreased the amount of gluten selected by the rat from 40 to 20 g per 100 g of food eaten, selection was not related to the nutritional quality of the gluten. When graded levels of arginine (1.8, 3.6 or 7.2 g/100 g) were added to the gluten with or without lysine (0 or 6 g/100 g) the dietary protein selection was unaffected. The addition of ammonia (1.4 g/100 g as NH₄Cl) to gluten had initially the same effect as lysine (6 g/100 g) but with time protein intake returned to control levels. This effect of ammonia was unaltered by arginine additions. It is concluded that the mechanisms which lead to decreases in gluten selection caused by lysine or ammonia are not similar, and that the effects of lysine on gluten selection are not caused by an increased arginine requirement for urea cycle activity.     

自分泌生长因子对早期胚胎体外发育的影响(简报)

生长因子(Growth Factors,GFs)对于调节哺乳动物胚胎的早期发育和分化起着重要作用,这些GFs存在于雌性生殖道,也可由胚胎自身合成。正是由于这种自分泌GFs的存在,使我们可以通过改变胚胎培养密度或添加外源性GFs来定性或定量研究GFs对胚胎发育和分化的影响,对于了解GFs在分子水平上的作用途径和机制有着重要的意义。     

河南玉兰属两新变种

发表河南玉兰属两新变种,即：①狭被望春玉兰(Yulania biondii (Pamp.) D. L. Fu var. angustitepala D. L. Fu, T. B. Zhao et D. W. Zhao,var. nov.);②椭圆叶罗田玉兰(Y. pilocarpa (Z. Z. Zhao et Z. W. Xie) D. L. Fu var. ellipticifolia D. L. Fu, T. B. Zhao et J. Zhao,var. nov.)。     

刺叶柄棘豆的一个新变型--白花刺叶柄棘豆

描述了棘豆属(豆科)刺叶柄棘豆(Oxytropis acipblla Ledeb．)的一个新变型：白花刺叶柄棘豆O．aciphylla Ledeb．f．albiflora Z．Y．Chang,Z．H．Wu et L．R．Xu。原变型的花冠为红紫色或蓝紫色,而新变型的花冠为白色。     

The effect of intrauterine infusions of prostaglandin E2 on luteal function in nonpregnant gilts

Two trials were conducted to study the effects of intrauterine infusions of prostaglandin E(2) (PGE(2)) on luteal function in nonpregnant gilts. Cannulae were surgically implanted on day 9 postestrus into the lumen of each horn with a cephalic vein cannula inserted for collection of peripheral blood. Intrauterine infusions of 0, 25, 75 or 200 mug of PGE(2) were initiated at 0900 h on day 12 and administered thereafter every 12 hr until estrus or day 22 in the first trial. The second trial protocol included an increase in the dose of PGE(2) administered as well as the frequency of infusion. Infusion of 0, 200, 300 or 400 mug PGE(2) was begun at 0300 h on day 12 and continued every 6 hr until estrus or day 22. Cephalic plasma samples for progesterone analysis were collected every six hours from 0300 h on day 11 to 2100 h on day 26 in both trials. In Trial 1 mean plasma progesterone concentrations for all treatments were not different (P>0.05) from the controls on any given day of the estrous cycle. Interestrous interval was unaffected by intrauterine infusion of PGE(2). The mean plasma progesterone concentrations for all treatments were not different (P>0.05) from the controls on days 11-18 of the estrous cycle in Trial 2. However, plasma progesterone concentrations for the 200-mug and 300-mug PGE(2) groups appeared to be greater than the controls on days 14 and 15, indicating a possible delay in the decline of progesterone for these groups. The mean plasma progesterone concentrations for the treatment groups were lower (P<0.05) than the controls on days 20-26 of the cycle. treatment cycle length did not differ (P>0.05) from previous cycle length; thus treatment with PGE(2) had no effect on interestrous interval. PGE(2) may have retarded the decline of progesterone secretion by the corpus luteum in some cases, but at these dosages and frequencies of administration PGE(2) was ineffective in prolonging luteal maintenance.