5-氨基-2-苯氨基-噻唑-4-苯甲酸乙酯的合成方法

根据活性亚结构拼接原理,利用aza-Wittg法合成5-氨基-2-苯氨基噻唑-4-苯甲酸乙酯化合物,通过1HNMR,EI-MS分析等方法对合成的化合物进行了结构表征。     

Nicotinamide/nicotinic acid mononucleotide adenylyltransferase, new insights into an ancient enzyme

Nicotinamide/nicotinic acid mononucleotide adenylyltransferase (NMNAT) has long been known as the master enzyme in NAD biosynthesis in living organisms. A burst of investigations on NMNAT, going beyond enzymology, have paralleled increasing discoveries of key roles played by NAD homeostasis in a number or patho-physiological conditions. The availability of in-depth kinetics and structural enzymology analyses carried out on NMNATs from different organisms offer a powerful tool for uncovering fascinating evolutionary relationships. On the other hand, additional functions featuring NMNAT have emerged from investigations aimed at unraveling the molecular mechanisms responsible for complex biological phenomena such as neurodegeneration. NMNAT appears to be a multifunctional protein that sits both at the core of central metabolism and at a crossroads of multiple cellular processes. The resultant wealth of biochemical data has built a robust framework upon which design of NMNAT activators, inhibitors or enzyme variants of potential medical interest can be based.     

硼酸基亲和层析纯化5-甲基尿苷

利用聚乙烯系大孔聚合物与间氨基苯硼酸偶联制备亲和介质，配基密度为每克湿胶0．92mmol。最佳吸附条件为pH9．0和2．0mol/LNaCl；最佳洗脱条件为0．1mol/LHCl。测定了吸附等温线，算得解离常数Kd为0．155mol/L，最大吸附量qm为每克湿胶78．8mg。将含有胸腺嘧啶的5－甲基尿苷溶液进行亲和层析，5－甲基尿苷收率为56．3％。     

钯(Ⅱ)与二溴对甲基偶氮甲磺显色反应的研究

钯(Ⅱ)与二溴对甲基偶氮甲磺在硝酸介质中形成组成比为1∶2的绿蓝色的配合物,其最大吸收波长位于620nm处,表观摩尔吸光系数6ε20=4.2×104L.mol-1.cm-1,钯的质量浓度在0.00~0.80mg.L-1范围内符合比尔定律.该法常温下可在水相中直接测定微量钯,并应用于废钯催化剂回收液中钯含量的测定.     

C5馏分中环戊二烯和双环戊二烯的气相色谱分析

采用气相色谱仪对C5馏分中环戊二烯和双环戊二烯的含量进行了分析，研究表明，选用PEG－400／6201（80－100目）柱，可成功地将环戊二烯和双环戊二烯从C5馏分中的其它烃类分离出来，环戊二烯和双环戊二烯的含量分别为2．0％，20．5％（质量百分比），图谱中出峰数少且峰形好，检测方法简单，快速，重现性好，为C5馏分中环戊二烯和双环戊二烯的利用提供了一种可行，实用的原料分析方法。     

Gas-Phase Beckmann Rearrangement of Cyclohexanone Oxime over B-ZSM-5 Derived Titanosilicalite

IntroductionDue to its remarkable catalysis,titanosilicalite hasattracted considerable attention[13 ] . Titano-silicalite- 1 prepared by hydrothermal synthesis[4]exhibits much better catalytic performance for thegas- phase Beckmann rearrangement ofcyclohexanone oxime ( CHO ) into lactam thanother solid catalysts,such as silicalite- 1 [4] ,B2 O3 /Zr O2 [5] ,Ta2 O5/ Si O2 [6] ,HZSM- 5 [7] ,Hβ[8] ,andHMCM- 41 [9] .However,it is surprising that onlytwo papers have been published on the re…     

2.5维问题电阻率正演的新方法

利用格林函数导出了2．5维问题，以研究区域网格化中任意电性分布条件下空间电位所满足的边界积分方程．用边界元法解该方程求得地表和地下的电位分布，从而进行视电阻率模拟．运用该方法得出的计算结果与前人所作的数值模拟和实验结果进行对比表明，作者提出的方法克服了有限元法和α－中心法的许多缺陷，将其用于电阻率成像可大大提高成像质量，扩大电阻率成像技术的实用范围．     

The enteric neural receptor for 5-hydroxytryptamine

Summary An enteric neural receptor for serotonin (5-HT) has been characterized. This receptor was assayed, using³H-5-HT as a radiologand, by rapid filtration of isolated enteric membranes and by radioautography. In addition, intracellular recordings were made from ganglion cells of the myenteric plexus. High affinity, saturable, reversible, and specific binding of³H-5-HT was demonstrated both to membranes of the dissected longitudinal muscle with adherent myenteric plexus and the mucosa-submucosa. Radioautographs showed these³H-5-HT binding sites to be in myenteric ganglia and in a broad unresolved band at the mucosal-submucosal interface. Antagonists active at receptors for other neurotransmitters than 5-HT, at either of the two known types of CNS 5-HT receptor, and at 5-HT uptake sites on serotonergic neurons failed to inhibit binding of³H-5-HT. The structural requirements of analogues for binding to the enteric 5-HT receptor matched the known pharmacology of M or neural 5-HT receptors. A novel 5-HT antagonist was found. This compound, N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide (5-HTP-DP), antagonized the action of 5-HT on type II/AH cells of the myenteric plexus but did not affect the release or actions of acetylcholine (nicotinic or muscarinic) or substance P. 5-HTP-DP was also an equally potent displacer of³H-5-HT from its binding sites on enteric membranes. It is concluded that the sites responsible for specific binding of³H-5-HT are enteric M or neural 5-HT receptors. These receptors differ from those now known to be present in the CNS.