不同地区红景天植物红景天苷含量比较研究

采用高效液相色谱法(HPLC)测定了6种不同地区红景天植物红景天苷含量.以甲醇为提取溶剂,室温超声提取45 min,HPLC测定条件:岛津C18柱(4.6×250 mm,5 μm);流动相为甲醇∶水=3∶7;柱温25℃;检测波长为275 nm.结果表明,红景天苷含量分别为:大花红景天0.36%,狭叶红景天(狮子七)0.32%,宽果红景天0.14%,白三七0.04%,在小丛红景天、洮河红景天中未检测到红景天苷.     

青藏高原红景天药材的HPLC指纹图谱

利用高效液相色谱法建立了青藏高原红景天的色谱指纹图谱。固定相采用C28反相色谱柱,流动相为甲醇：0．1%磷酸水(v／v=15：85);检测波长220nm;流速为1．0mL／min。通过比较发现红景天样品的8个主要共有峰．可作为鉴别红景天药材的主要依据。方法简便快速。为中药品种的鉴定提供了较全面的信息。     

高效液相色谱法同时测定五指山绿茶中5种儿茶素类成分

建立了同时测定五指山绿茶中表儿茶素(EC)、儿茶素(C)、表没食子儿茶素没食子酸酯(EGCG)、表儿茶素没食子酸(ECG)和表没食子儿茶素(EGC)的高效液相色谱法。色谱条件为:HIQ SIL C18 V色谱柱(250 mm×4.6 mm,5μm);乙腈-1.5%冰乙酸体系为流动相进行梯度洗脱;紫外检测器,检测波长280 nm;流速为1.0 mL.min-1;进样量10μL;柱温为35℃。在优化条件下,5种儿茶素类成分的浓度分别在15~300、10~200、10~200、20~400和10~200μg.mL-1与色谱峰面积之间的线性关系良好;平均回收率在96.20%~99.64%之间;RSD在1.12%~2.24%之间。该方法简便、快速、准确,可用于绿茶中儿茶素的质量控制。     

HPLC法同时测定千斤拔属植物7种黄酮的含量

目的:测定千斤拔属7种植物中的7种黄酮类的含量,为千斤拔类药材质量控制提供依据。方法:色谱条件为Hedera C18色谱柱(250 mm×4.6 mm,5.0μm):流速1.2 mL/min,流动相为0.5%HAc水和乙腈梯度洗脱,柱温35℃,检测波长263 nm。结果:七种黄酮类成分在90 min内达到现行分离,线性关系良好(,R2>0.9995),日内、日间精密度、稳定性和重复性的RSD≤3.0%。该法成功的应用于千斤拔药材7种黄酮的评均回收率分别为96.94%～105.29%(RSD≤2.98%)结论:本方法准确、快速、重现性好,不同品种的千斤拔药材质量存在差异,可以为研究千斤拔药材的质量标准提供依据。     

萆薢类药材的HPLC指纹图谱研究

应用HPLC方法测定了薯蓣属根状茎组10种1亚种1变种植物23个样本,建立了萆薢类药材总皂苷元粗提物的HPLC指纹图谱.色谱柱为Zorbax Eclipse XDB-C_(18)柱(4.6×250 mm,5 μm),流动相为乙腈-水,柱温30℃,检测波长为203 nm.结果表明,用上述条件所建立的指纹图谱共标示出7个共有峰,且可较全面地反映萆薢类药材的皂苷元类成分,为萆薢类药材薯蓣属根状茎组植物鉴别及质量控制提供一种方法.     

UPLC-MRM-MS法测定头花蓼药材中7个指标成分

建立头花蓼药材中没食子酸、原儿茶酸、陆地棉苷、槲皮苷、儿茶素、槲皮素-3-O-(2″-没食子酰基)-鼠李糖苷及槲皮素的UPLC-MRM-MS检测方法。色谱采用Waters BEH C18(2.1 mm×50 mm,1.7μm)色谱柱,以0.1%甲酸乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,质谱采用多反应离子监测(MRM)检测。没食子酸、原儿茶酸、陆地棉苷、槲皮苷、儿茶素、槲皮素-3-O-(2″-没食子酰基)-鼠李糖苷及槲皮素分别在0.136~32.965、0.031~7.481、0.022~5.300、0.076~18.433、0.085~20.737、0.017~4.147、0.128~31.029μg/m L浓度范围线性关系良好,平均回收率为91.23%~105.33%,RSD3%,精密度、重复性和稳定性良好。此方法操作简便,快速,灵敏度高,可用于头花蓼药材中主要活性成分的含量测定,并为头花蓼药材质量控制提供了新方法。     

对叶百部药材中四种主要生物碱的分布规律

目的:了解百部药材中主要生物碱的含量和分布规律,为百部药材的质量控制提供依据。方法:采用反向HPLC-ELSD方法对百部药材中4种主要生物碱金刚大碱、百部新碱、新对叶百部碱和对叶百部碱的含量就行了测定,以0.1%三乙胺-甲醇(43∶57)为流动相,Agilent C18色谱柱(4.6 mm×250 mm,5μm),柱温30℃,流速1m L/min;ELSD漂移管温度为80℃,氮气流速为2.1 m L/min,增益为8。结果:83批百部药材含金刚大碱、百部新碱、新对叶百部碱和对叶百部碱的药材分别有27、48、22和48批,其平均含量分别为1.98、4.75、3.73和5.34 mg/g;含有1~4种生物碱的药材分别有38、28、17和0批次,其中对叶百部碱与其余三种生物碱中任意一种同时出现的概率较高;购于安徽亳州和广州清平药市的药材不含新对叶百部碱。结论:本文建立的含量测定方法简便、准确、可靠;含量测定结果说明4种生物碱在药材中的分布具有趋单性,仅含一种生物碱的药材占45.8%,含2种及以上生物碱的药材占54.2%。本文研究结果对于对照品短缺情况下,对购买百部药材化学成分的预测具有一定的指导意义。     

高效液相色谱法测定红景天根中红景天甙的含量

建立了一种高效液相色谱法测定红景天根中红景天甙的含量。色谱柱为Hypersil—C18（5μm,150mm×4．6mm）,甲醇-水为流动相,梯度洗脱,柱温25℃,在250nm波长处检测。研究结果表明：红景天甙的检测限为50μg/L,线性范围为4—40mg／L,回归方程为Y=5．6348X-4．0931,r=0．9996,加样回收率为98．05％。方法操作简便、快速、准确。     

吉林12种蒲公英HPLC指纹图谱研究

通过比较吉林产不同种蒲公英HPLC指纹图谱,探讨吉林产蒲公英HPLC指纹图谱的特点,为蒲公英药材的质量控制提供理论参考。采用HPLC方法,以Agilent Extend-C18(250 mm×4.6 mm,5μm)为色谱柱,以甲醇-0.5%冰醋酸水溶液梯度洗脱;检测波长为323 nm,流速为1.000 mL·min-1,柱温35℃,进样量为20μL,检测了12种吉林产不同种类蒲公英药材,确立了9个共有峰,建立了蒲公英对照指纹图谱,计算各被测样品的HPLC指纹图谱的整体相似度,并指认了绿原酸、咖啡酸、总黄酮3个特征峰,比较了上述成分在不同药材中的含量,定量结果表明,3种成分平均含量分别为0.027%、0.026%、0.128%。所建立的指纹图谱具有良好的精密度、重现性和稳定性,可作为吉林产蒲公英药材的质量控制标准。     

柴胡红景天化学成分的研究

采用正相与反相硅胶柱色谱和薄层色谱分离纯化的方法,从景天科红景天属植物柴胡红景天(Rhodiola bupleuroides)根茎70%乙醇提取物的乙酸乙酯萃取部分中分离得到7个化合物,用光谱分析(UV,IR,MS,1H-NMR,13C-NMR)和化学反应鉴定化合物分别为:没食子酸(1)、山奈酚-7-O-α-L-吡喃鼠李糖苷(2)、草质素-7-O(3″-O-β-D-葡萄糖基)-α-L鼠李糖苷(3)、槲皮素(4)、丁香酸(5)、3,5-二甲氧基-4-羟基-苯甲酸-7-O-β-D-葡萄糖苷(6)、β-谷甾醇(7).以上化合物均为首次从该植物中分离得到,其中化合物5和6为首次从红景天属植物中发现.     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

2017年中国植物科学若干领域重要研究进展

2017年中国植物科学继续保持高速发展态势, 重大成果频出, 具体表现在中国植物学家在国际顶级学术期刊发表的文章数量平稳上升。中国植物科学领域的研究工作者成果精彩纷呈, 如新型广谱抗病机制的发现、水稻广谱抗病遗传基础及机制和疫霉菌诱发病害成灾机制研究等。2017年中国生命科学领域十大进展评选中, 有两项植物科学领域的研究成果入选。水稻生物学、进化与基因组学和激素生物学等领域学科发展突出。另外, 值得一提的是, 长期从事高等植物与代谢途径调控分子网络研究和水稻品种设计育种的李家洋院士的研究成果“水稻高产优质性状形成的分子机理及品种设计”荣获2017年国家自然科学一等奖。这一具有重大国际影响的开创性贡献标志着中国植物科学在该领域的国际科学前沿居于引领和卓越地位。该文对2017年中国本土科学家在植物科学若干领域取得的重要研究成果进行了系统梳理, 旨在全面追踪和报道当前中国植物科学领域发展的最新前沿动态, 与广大读者共同分享我国科学家所取得的辉煌成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义。综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义.综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望.     

Morphine-potentiated platelet aggregation in in vitro and platelet plug formation in in vivo experiments

The detailed mechanisms underlying morphine-signaling pathways in platelets remain obscure. Therefore, we systematically examined the influence of morphine on washed human platelets. In this study, washed human platelet suspensions were used for in vitro studies. Furthermore, platelet thrombus formation induced by irradiation of mesenteric venules with filtered light in mice pretreated with fluorescein sodium was used for an in vivo thrombotic study. Morphine concentration dependently (0.6, 1, and 5 microM) potentiated platelet aggregation and the ATP release reaction stimulated by agonists (i.e., collagen and U46619) in washed human platelets. Yohimbine (0.1 microM), a specific alpha(2)-adrenoceptor antagonist, markedly abolished the potentiation of morphine in platelet aggregation stimulated by agonists. Morphine also potentiated phosphoinositide breakdown and intracellular Ca(2+) mobilization in human platelets stimulated by collagen (1 microg/ml). Moreover, morphine (0.6-5 microM) markedly inhibited prostaglandin E(1) (10 microM)-induced cyclic AMP formation in human platelets, while yohimbine (0.1 microM) significantly reversed the inhibition of cyclic AMP by morphine (0.6 and 1 microM) in this study. The thrombin-evoked increase in pH(i) was markedly potentiated in the presence of morphine (1 and 5 microM). Morphine (2 and 5 mg/g) significantly shortened the time require to induce platelet plug formation in mesenteric venules. We concluded that morphine may exert its potentiation in platelet aggregation by binding to alpha(2)-adrenoceptors in human platelets, with a resulting inhibition of adenylate cyclase, thereby reducing intracellular cyclic AMP formation followed by increased activation of phospholipase C and the Na(+)/H(+) exchanger. This leads to increased intracellular Ca(2+) mobilization, and finally potentiation of platelet aggregation and of the ATP release reaction.     

Changes in aquatic vegetation in Rhine floodplain streams in Alsace in relation to disturbance

Abstract. Changes are described in aquatic vegetation in oligotrophic, groundwater-fed Rhine floodplain streams in Alsace (eastern France), resulting from disturbance. Disturbance factors include changes in nutrients, either permanent ones - effluent from a waste water treatment plant or trout hatcheries - or periodic ones: flooding. Regular inputs of high levels of phosphate and ammonia modified the macrophyte vegetation in these streams. The floristic composition, which was characteristic of oligotrophic waters upstream of the eutrophicated sector, changed to that of a eutrophic situation as originally found downstream. Periodic disturbance by floods which normally occur once a year, irregularly eutrophicates the small streams, causing the development of a mixture of eutrophic and oligotrophic species. Six macrophyte communities are distinguished, indicating different trophic levels. The aquatic vegetation is adapted to the variations of phosphate and ammonia levels. Hence, aquatic macrophytes can be used as bio-indicators of fluctuations in water nutrient levels in relation to the type of disturbance.     

Progress in glial cell studies in some laboratories in China

Glial cells in the central nervous system(CNS) consist of a heterogeneous population of cell types,each characterized by distinct morphological features,physiological properties,and specific markers.In contrast to the previous view that glial cells were passive elements in the brain,accumulating evidence suggests that glial cells are active participants in various brain functions and brain disorders.This review summarizes recent progress of glial cell studies from several groups in China,ranging from studie...