盐胁迫下龙爪稷愈伤组织内脯氨酸和丙酮酸含量变化的关系

盐胁迫下，龙爪稷愈伤组织内脯氨酸积累，在胁迫后第１～７ｄ内脯氨酸变化迅速；游离氨基酸构成发生变化；组织内丙酮酸含量出现高峰，此峰与脯氨酸峰在出现时间上有一定关系．     

丙酮酸脱氢酶复合体的研究进展及应用

综述了丙酮酸脱氢酶复合体（PDHc）的组成、结构功能、调控机制、缺陷疾病及在医学和农业中的应用.丙酸酸脱氢酶系是定位在线粒体中的多酶复合体,它是由丙酮酸脱氢酶（E1）、二氢硫辛酸乙酰转移酶（E2）、二氢硫辛酸脱氢酶（E3）和一些辅助因子组成.高等生物中PDHc活性的调节主要是通过对其E1的磷酸化和去磷酸化来实现的,而细菌的PDHc的活性主要是通过别构效应来调节,PDHc缺陷导致代谢障碍,组织受损.     

丙酮酸转运体AtMPC3介导植物干旱胁迫响应机理研究

在干旱胁迫下,植物通过自身复杂而有效的应对机制减少水分散失,其中关闭植物气孔降低蒸腾作用是一个重要环节。脱落酸(ABA)是植物响应干旱胁迫产生的可以诱导气孔关闭、减少水分散失的重要植物激素。丙酮酸是光合作用糖酵解的产物,需要借助线粒体丙酮酸转运体(MPCs)进入线粒体中进行后续物质和能量代谢。本研究发现拟南芥线粒体丙酮酸转运体AtMPC3参与介导植物干旱胁迫响应,在外源施加ABA条件下,AtMPC3基因缺失突变体的气孔较野生型开度更小,植物失水率更低,表现出更强的抗旱能力。结果说明AtMPC3在脱落酸促进植物气孔关闭及干旱应答过程中的重要作用,对于提高植物抗旱能力以及作物产量提升具有潜在应用价值及重要意义。     

Lewis酸催化三组分合成喹啉-2,4-二羧酸酯类化合物

采用价廉易得的无水三氯化铝、三氯化铁、氯化铜等Lewis酸催化取代芳胺、乙醛酸乙酯和丙酮酸甲酯三组分一步反应,高效合成了4个喹啉-2,4-二羧酸酯类化合物.产物通过柱层析分离纯化,并采用FT-IR、~1H NMR、~(13)C NMR和元素分析等手段进行了结构表征.探讨了反应机理和取代芳胺的分子结构对反应的影响规律,为该类新颖化合物的分子设计与合成方法提供参考.该方法具有原料廉价易得、反应条件温和、原子经济性高、产率高等优点.     

Toll样受体4对饥饿代谢的调控作用

Toll样受体4( Toll-like receptor 4,TLR4)的激活能介导炎症反应.对于高脂饲料喂养导致的肥胖小鼠,TLR4激活所引起的炎症反应是引起胰岛素抵抗和代谢紊乱的重要原因.虽然已知TLR4参与病理性代谢反应,但它在生理状态下对代谢是否具有调控作用尚不清楚.我们将TLR4基因敲除(TLR4~-/-)小...     

丙酮酸钙对摔跤队男性运动员脂质代谢的影响

为探讨丙酮酸钙对摔跤队男性运动员体重、体脂含量、血脂、血糖和胰岛素水平及对无氧运动能力的影响,以天津体育学院摔跤队男性运动员为研究对象,选取40人,随机分为4组:安慰剂组10人,低剂量组10人(50 m g/kg.d),中剂量组10人(100 m g/kg.d),高剂量组10人(150m g/kg.d),给服丙酮酸钙4周.观察服用丙酮酸钙前后运动员体重、皮褶厚度、血脂、血糖和胰岛素水平等的变化.结果表明,中、高剂量组运动员体重、BM I显著低于试验前(P<0.05);高剂量组运动员皮褶厚度显著低于试验前(P<0.05);各组试验前后甘油三酯(TG)、血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-L)、血糖(GLU)和胰岛素(IN S)含量差异无统计学意义.     

Pyruvate dehydrogenase kinase 4 expression is synergistically induced by AMP-activated protein kinase and fatty acids

Organs are flexible as to which substrates they will use to maintain energy homeostasis. Under well-fed conditions, glucose is a preferred substrate for oxidation. During fasting, fatty acid oxidation will become a more important energy source. Glucose oxidation is decreased by fatty acids, a process in which the pyruvate dehydrogenase complex (PDH) and its regulator pyruvate dehydrogenase kinase 4 (PDK4) play important roles. It is currently unknown how energy status influences PDH activity. We show that AMP-activated protein kinase (AMPK) activation by hypoxia and AICAR treatment combined with fatty acid administration synergistically induce PDK4 expression. We provide evidence that AMPK activation modulates ligand-dependent activation of peroxisome proliferator-activated receptor. Finally, we show that this synergistic induction of PDK4 decreases cellular glucose oxidation. In conclusion, AMPK and fatty acids play a direct role in fuel selection in response to cellular energy status in order to spare glucose. S. M. Houten, M. Chegary: These two authors contributed equally to this work. Received 11 July 2008; received after revision 26 January 2009; accepted 02 February 2009     

乳酸乙酯催化氧化合成丙酮酸乙酯

在固定床反应器上研究了Ａｇ－ＮａＹ分子筛催化剂常压气相催化氧化乳酸乙酸乙酯合成丙酮酸乙酯的反应。运用Ｘ射线粉末衍射法（ＸＲＤ）、扫描电镜法（ＳＥＭ）、比表面及孔容测定法（ＢＥＴ）等手段表征了催化剂的物理和化学性质,结果显示５００℃焙烧,载银质量百分数为６４．２％的催化剂具有最好的活性和稳定性。     

Glucose formation from methylglyoxal in hepatocytes from streptozotocin-induced diabetic mice: the effect of insulin

Acetol and methylglyoxal are intermediates of the intrahepatic metabolism of acetone leading to pyruvate formation. In hepatocytes prepared from fasted streptozotocin-induced diabetic mice, net glucose production could be measured from methylglyoxal but not from acetone or acetol. Insulin increased glucose formation from methylglyoxal in a concentration-dependent manner, whereas it was ineffective when pyruvate was used as substrate. Drug oxidation, as evidenced byp-aminophenol formation from aniline, was enhanced by methylglyoxal, and insulin proved to be stimulatory in this case as well. It is concluded that insulin might be involved in the regulation of glucose formation from methylglyoxal, but its mode of action is not yet clear.     

丙酮酸钙合成工艺的研究

研究了酒石酸合成丙酮酸钙的工艺，首先选择适宜的丙酮酸生产工艺路线，利用合适的溶剂，得到高质量的丙酮酸，进而确定合成丙酮酸钙工艺条件，提高产品收率，收率达96％，并得到高品质的丙酮酸钙，生产成本大幅度地降低。