Imidazolines促胰岛素分泌作用机制的研究

目的观察ｉｍｉｄａｚｏｌｉｎｅｓ：ｐｈｅｎｔｏｌａｍｉｎｅ，ｅｆａｒｏｘａｎ和ｉｄａｚｏｘａｎ对ＡＴＰ调节的钾离子通道的影响，从而探讨其促胰岛素分泌的作用机制。方法用“内面向外”的膜片钳制技术，在培养的无性系的ＲＩＮｍ５Ｆ胰岛素分泌细胞进行实验。结果ｐｈｅｎｔｏｌａｍｉｎｅ５０μｍｏｌ·Ｌ－１明显抑制ＡＴＰ调节的钾离子通道，显著降低通道开放的概率。Ｅｆａｒｏｘａｎ５０μｍｏｌ·Ｌ－１明显降低通道开放的概率，抑制钾离子通道的开放，但作用维持时间短。ｉｄａｚｏｘａｎ５０μｍｏｌ·Ｌ－１对通道开放概率的影响不明显。结论ｐｈｅｎｔｏｌａｍｉｎｅ，ｅｆａｒｏｘａｎ和ｉｄａｚｏｘａｎ促胰岛素分泌的作用与阻断ＡＴＰ调节的钾离子通道有关。

Imidazolines对RINm5F胰岛素分泌细胞钾离子通道的作用

Ｉｍｉｄａｚｏｌｉｎｅｓ对ＲＩＮｍ５Ｆ胰岛素分泌细胞钾离子通道的作用梁日欣（药理教研室）刘晓光（附属第一医院）近年来的实验研究已经证明α２－肾上腺素受体阻断剂Ｉｍｉｄａｚｏｌｉｎｅｓ如：ｐｂｅｎｔｏｌａｍｉｎｅ［１］，Ｅｆａｒｏｘａｎ和Ｉｄａｚｏｘａ...

Hydroxy- and Aminoethyl Imidazolines of Cottonseed Oil Fatty Acids as Additives for Diesel Fuels

In the research, aminoethyl imidazolines of cottonseed oil fatty acids with diethylenetriamine have been synthesized using the ultrasonic device creating the effect of cavitation. The yield of imidazolines was 90% - 95%. The influence of the synthesized imidazolines on lubricity quality of low sulfur diesel fuels having low lubricating quality was studied. The results showed that at concentrations 200 - 250 ppm the synthesized imidazolines can be applied as additives enhancing lubricity quality of diesel fuels.

Clonidine－like Imidazolines系列化合物的QSAR研究

Ｃｌｏｎｉｄｉｎｅ－ｌｉｋｅＩｍｉｄａｚｏｌｉｎｅｓ系列化合物的ＱＳＡＲ研究孙红梅，谢前，周家驹（中国科学院化工冶金所计算机化学开放实验室，北京１０００８０）１介绍对于一系列具有相同母体的化合物来说，取代基的变化影响母体的空间几何构型、电子密度分布、...

An Efficient and Convenient Synthesis of Imidazolines and Benzimidazoles via Oxidation of Carbon-Nitrogen Bond in Water Media

The metal coordination complex K4[Fe（CN）6] is an efficient and environmentally benign catalyst for the syn- thesis of imidazolines and benzimidazoles from various aldehydes and 1,2-diamines in aqueous medium at room temperature. This protocol gives excellent yield of product with desired purity.

The synthesis of dialdehydes from dicarboxylic acids via imidazolines

DIALDEHYDES are important chemical industrial materials, which are widely used in textile,medicine, dye, binder, coating and so on. The traditional method for preparing dialdehydes is the catalytic oxidation of glycol. We have reported the reduction ring-opening reaction of inndazoline by NaBH4.In this note, the reduction of imidazoline by sodium and ethanol is studied. A new synthetic method for the preparation of dialdehydes from dicarboxylic acids

Preparation of imidazolines from aziridines and nitriles via TfOH promoted Ritter process

An efficient preparation of imidazolines from nitriles and aziridines in the presence of TfOH via Ritter reaction is described. It indicates that different kinds of nitriles can undergo the process. Among the nitriles, pivalonitrile is proven to be better than acetonitrile. The reaction is performed at room temperature and the yields are excellent.

Preparation of ferrocenyl imidazolines using bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate

An efficient synthesis of ferrocenyl imidazolines starting from ferrocenyl carboxylic acids has been developed. Bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate was used to convert smoothly ferrocenyl carboxylic amides bearing an amine side chain, derived from ferrocenyl carboxylic acids and 1,2-diamines, to their corresponding ferrocenyl imidazolines.

Neuroprotective effects of receptor imidazoline 2 and its endogenous ligand agmatine

Receptor imidazoline 2 （I2） is one of the imidazoline receptors with high affinity for [^3H]-idazoxan. Receptor I2, being classified into I2A and I28 subtypes, is mainly localized to the outer membrane of mitochondria in liver, kidney and brain. Receptor I2, displaying high similarity of sequence with monoamine oxidase-B （MAO-B）, is structurally related to MAO-B, but the I2 imidazoline binding site （IEBS） with ligand is distinct from the catalytic site of MAO-B. Agmatine is the endogenous ligand of receptor I2. Accumulating evidence have revealed that the activation of receptors I2 may produce neuroprotective effects by increasing expression of glial fibriUary acidic protein （GFAP） in astrocytes, inhibiting activity of MAO, reducing calcium overload in cells. Agmatine exerts neuroprotection against ischemia-hypoxia, injury, glutamateinduced neurotoxicity by activating imidazoline receptors, blocking N-methyl-D-aspartate （NMDA） receptor, inhibiting all isoforms of nitric oxide synthase （NOS）, and selectively blocking the voltage-gated calcium channels （VGCC）. It would be expected that agmatine is one of the potential neuroprotective agents.

Corrosion Inhibition of Imidazoline Derivates with Benzene Rings on Mild Steel in CO_2-Saturated Brine Solution

Corrosion inhibition of three imidazoline derivates with different numbers of benzene rings,namely 2-phenyl-1-ethylamino imidazoline（CI-1）,2-phenyl-1-ethylamino-1-methylbenzyl quaternary imidazoline（CI-12） and 2-phenyl-1-benzoyl ethylamino imidazoline（CI-13）,on mild steel in CO2-saturated brine solution was evaluated by mass-loss method and potentiodynamic polarization method.The results show that the three imidazoline derivates can inhibit CO2 corrosion effectively with CI-12 ranking the highest.They mainly restrain the anodic dissolution and act as anodic-type inhibitors.The adsorptions of these derivates on the mild steel surface follow the Langmuir adsorption isothermal equation and belong to chemical adsorption.

Studies of Self-assembled Monolayers Formed by Imidazofine on Iron Surface by SEM and SECM

The self-assembled monolayers （SAMs） of imidazoline （IM） on the iron surface were characterized by scanning electron microscope （SEM） and scanning electrochemical microscopy （SECM）. The results showed that SAMs were an effective inhibition film for iron.

Comparative effects of idazoxan, efaroxan, and BU 224 on insulin secretion in the rabbit: Not only interaction with pancreatic imidazoline I2 binding sites

The nature of the binding site(s) involved in the insulin secretory activity of imidazoline compo- unds remains unclear. An imidazoline I2 binding site (I2BS) has been neglected since the classic I2 ligand, idazoxan, does not release insulin. Using the rabbit as an appropriate model for the study of this type of binding sites, we have tried to re-evaluate the effects of idazoxan, the selective I2 compound BU 224, and efaroxan on insulin secretion. Mimicking efaroxan, idazoxan and BU 224 potentiated insulin release from perifused islets in the presence of 8 mM glucose. In static incubation, insulin secretion induced by idazoxan and BU 224 exhibited both dose and glucose dependencies. ATP-sensitive K+ (KATP) channel blockade, though at a different site from the SUR1 receptor, with subsequent Ca2+ entry, mediates the insulin releasing effect of the three ligands. However, additional MAO independent intracellular steps in stimulus- secretion coupling linked to PKA and PKC activation are only involved in the effect of BU 224. Therefore, both an I2 related binding site at the channel level shared by the three ligands and a putative I3-intracellularly located binding site stimulated by BU 224 would be mediating insulin release by these compounds. In vivo experiments reassess the abilities of idazoxan and BU 224 to enhance glucose-induced insulin secretion and to elicit a modest blood glucose lowering response.

Adaptability of Polymer-Containing Sewage Corrosion Inhibitor

The polymer content in the produced water from Tuoliu Station is about 20 mg/L. Cationic imidazoline-type corrosion inhibitor is used to corrosion control of sewage. The corrosion inhibitor can react with the negatively charged materials such as anionic polymer and suspended substance by adsorption and merging to form complex aggregates, so that the suspended solids content increases, resulting in suspended solids content of exported sewage has been high. So a new type of non-ionic corrosion inhibitor has been developed and field trials have been performed. The results show that non-ionic corrosion inhibitor can effectively reduce the suspended solids content of wastewater while ensuring the corrosion rate of wastewater.

Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats

BACKGROUND Despite overt insulin resistance,adipocytes of genetically obese Zucker rats accumulate the excess of calorie intake in the form of lipids.AIM To investigate whether factors can replace or reinforce insulin lipogenic action by exploring glucose uptake activation by hydrogen peroxide,since it is produced by monoamine oxidase(MAO)and semicarbazide-sensitive amine oxidase(SSAO)in adipocytes.METHODS 3H-2-deoxyglucose uptake(2-DG)was determined in adipocytes from obese and lean rats in response to insulin or MAO and SSAO substrates such as tyramine and benzylamine.14C-tyramine oxidation and binding of imidazolinic radioligands[3H-Idazoxan,3H-(2-benzofuranyl)-2-imidazoline]were studied in adipocytes,the liver,and muscle.The influence of in vivo administration of tyramine+vanadium on glucose handling was assessed in lean and obese rats.RESULTS 2-DG uptake and lipogenesis stimulation by insulin were dampened in adipocytes from obese rats,when compared to their lean littermates.Tyramine and benzylamine activation of hexose uptake was vanadate-dependent and was also limited,while MAO was increased and SSAO decreased.These changes were adipocyte-specific and accompanied by a greater number of imidazoline I2 binding sites in the obese rat,when compared to the lean.In vitro,tyramine precluded the binding to I2 sites,while in vivo,its administration together with vanadium lowered fasting plasma levels of glucose and triacylglycerols in obese CONCLUSION The adipocytes from obese Zucker rats exhibit increased MAO activity and imidazoline binding site number.However,probably as a consequence of SSAO down-regulation,the glucose transport stimulation by tyramine is decreased as much as that of insulin in these insulin-resistant adipocytes.The adipocyte amine oxidases deserve more studies with respect to their putative contribution to the management of glucose and lipid handling.

Study of the Synergistic Effect Between Corrosion Inhibitors by Using Fractional Free Volume

The fractional free volumes(FFVs)of the adsorption films formed with different ratios of dipropargyl methoxythiourea imidazoline(DPFTAI)and pyridine quaternary ammonium salt(16BD)were calculated by simulation to determine their synergistic corrosion inhibition effect.The results suggest that the composite corrosion inhibitor at the molar ratio between DPFTAI and 16BD of 4:1 gives the best corrosion inhibition effect.This simulation method to predict the synergistic effect between corrosion inhibitors was further validated by mass loss and electrochemical experiments.This finding delivers valuable understandings of inhibition mechanism of corrosion inhibitors.

Chiral Imidazoline Ligands and Their Applications in Metal-Catalyzed Asymmetric Synthesis

As a structural analog of oxazoline,imidazoline(4,5-dihydroimidazole)has received much attention in the rational design of chiral ligands.The additional N-substituent provides broader space for fine-tuning of electronic and steric effects,and it offers a good handle for immobilizing onto solid supports.In the past decades,imidazoline ring has emerged as a powerful candidate for the design of chiral nitrogen-containing ligands,as well as a significant alternative for oxazoline ring.Various chiral imidazoline ligands have been designed and utilized in asymmetric organic reactions.These new catalysts can not only be applied in classical reactions,but also be employed to develop new organic reactions with high enantioselectivities.This review provides an overview of chiral imidazoline ligands.Their applications in asymmetric synthesis are also summarized.

Effects of the number of imidazoline ring and the length of alkyl group chain of imidazoline derivatives on corrosion inhibition of carbon steel in HCl solution:Molecular simulation and experimental validation

The effects of the number of imidazoline ring and the length of alkyl group chain of imidazoline derivatives were investigated using quantum chemical calculation,molecular dynamics simulation and experimental techniques.Three corrosion inhibitors including symmetrical lauric acid imidazoline(SAI),tetracyclic lauric acid imidazoline(LAI),and symmetric stearic acid imidazoline(SPI)were synthesized and their inhibition performance was evaluated using weight loss measurement,electrochemical techniques and surface characterization.The results show that SAI and LAI with the same length of alkyl group chain,LAI with more imidazoline rings could supply a better inhibition performance since the increase of active sites.The increase of active sites attached to the metal surface may also change the distribution of corrosion inhibitor,which could limit inhibition performance improvement.While,SAI and SPI with the same number of imidazoline rings,SPI with longer alkyl group chain shows a better inhibition efficiency due to the better hydrophobic performance of alkyl groups.Among the three inhibitors,SPI shows the best inhibition performance,indicating that the alkyl group chain length affects the inhibition performance more obvious than the number of the imidazoline rings.

The reduction ring-opening reaction of imidazoline

A new reduction ring-opening reaction of 2-imidazoline with sodium borohydride is reported, and the effect of reaction condition on the yield, reaction mechanism and the use of the new reaction in synthesis of ethylenediamine derivatives are discussed. A new method for the preparation of unsymmetrical substituted ethylenediamine via the reduction ring-opening reaction of imidazoline is provided.

New Palladium-Imidazole and Imidazoline Complexes:Structures and Reactivity in Coupling Reaction

1 Results We have recently reported the Mizoroki-Heck reaction catalyzed by PdCl2 and imidazole ligands[1]. During the course of our study of palladium imidazole complex,we disclosed the synthesis of trans-Pd(Ln)2Cl2 by the reaction of PdCl2 with Ln (where L1=2-phenylimidazole,L2=2-phenylimidazole) in a 1∶2 molar ratio.The single crystals of trans-Pd(L1)2Cl2·2DMF (1a) and trans-Pd(L2)2Cl2 (2a) were obtained by following slow evaporation of DMF as a solvent. The single crystal of trans-Pd(L2)2Cl2 (2b) w...