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 mitochondr...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.展开更多
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-p...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.展开更多
Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with Various substituted phenols in the ...Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with Various substituted phenols in the presence of catalytic amount of potassium carbonate. The products are confirmed by H-1 NMR, MS, IR and elementary analysis.展开更多
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...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.展开更多
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% - 9...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.展开更多
We previously demonstrated that administering 2-（2-benzofuranyl）-2-imidazolin（2-BFI）, an imidazoline I2 receptor agonist, immediately after ischemia onset can protect the brain from ischemic insult. However, immed...We previously demonstrated that administering 2-（2-benzofuranyl）-2-imidazolin（2-BFI）, an imidazoline I2 receptor agonist, immediately after ischemia onset can protect the brain from ischemic insult. However, immediate administration after stroke is difficult to realize in the clinic. Thus, the therapeutic time window of 2-BFI should be determined. Sprague-Dawley rats provided by Wenzhou Medical University in China received right middle cerebral artery occlusion for 120 minutes, and were treated with 2-BFI（3 mg/kg） through the caudal vein at 0, 1, 3, 5, 7, and 9 hours after reperfusion. Neurological function was assessed using the Longa＇s method. Infarct volume was measured by 2,3,5-triphenyltetrazolium chloride assay. Morphological changes in the cortical penumbra were observed by hematoxylin-eosin staining under transmission electron microscopy. The apoptosis levels in the ipsilateral cortex were examined with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling（TUNEL） assay. The protein expression of Bcl-2 and BAX was detected using immunohistochemistry. We found the following： Treatment with 2-BFI within 5 hours after reperfusion obviously improved neurological function. Administering 2-BFI within 9 hours after ischemia/reperfusion decreased infarct volume and alleviated apoptosis. 2-BFI administration at different time points after reperfusion alleviated the pathological damage of the ischemic penumbra and reduced the number of apoptotic neurons, but the protective effect was more obvious when administered within 5 hours. Administration of 2-BFI within 5 hours after reperfusion remarkably increased Bcl-2 expression and decreased BAX expression. To conclude, 2-BFI shows potent neuroprotective effects when administered within 5 hours after reperfusion, seemingly by up-regulating Bcl-2 and down-regulating BAX expression. The time window provided clinical potential for ischemic stroke by 2-BFI.展开更多
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, ...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.展开更多
Herein we reported a one-pot synthesis of arylsubstituted imidazolin-2-ones by the cyclization of α-aminoacetophenone hydrochloride analogues 2 with arylisocyanates 3. Compared with other known synthetic route, this ...Herein we reported a one-pot synthesis of arylsubstituted imidazolin-2-ones by the cyclization of α-aminoacetophenone hydrochloride analogues 2 with arylisocyanates 3. Compared with other known synthetic route, this method resulted in higher yield.展开更多
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...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.展开更多
The structural properties and vibrational frequencies of 2-phenyl-2-imidazoline have been investigated using theoretical and techniques by which a good correlation was observed. The assignments of the vibrational mode...The structural properties and vibrational frequencies of 2-phenyl-2-imidazoline have been investigated using theoretical and techniques by which a good correlation was observed. The assignments of the vibrational modes were performed with the help of normal co-ordinate analysis following the Scaled Quantum Mechanical Force Field methodology. Natural bond orbital analysis and the highest occupied molecular orbital-lowest unoccupied molecular orbital gap analysis have been carried out. UV-visible spectrum of the compound was recorded and compared with the theoretical UV-visible spectrum of the title molecule using Symmetry Adapted Cluster-Configuration Interaction method which yielded good agreement. Our results reflect that the title compound can be used as good source of UV light.展开更多
Amino-imidazolin-2-imines(HAmIm)are introduced as a new class of strong monoanionic N,N’-chelating ligands for Cu(I)complexes.The reaction of HAmIm with CuCl,followed by deprotonation to give AmIm−,affords the dinucl...Amino-imidazolin-2-imines(HAmIm)are introduced as a new class of strong monoanionic N,N’-chelating ligands for Cu(I)complexes.The reaction of HAmIm with CuCl,followed by deprotonation to give AmIm−,affords the dinuclear precursor[Cu2(μ-AmIm)2],which serves as a versatile platform for the synthesis of structurally diverse mononuclear Cu(I)complexes.Coordination with diimine ligands(phenanthroline or neocuproine)yields distorted tetrahedral[Cu(AmIm)(diimine)]species featuring a broad UV/vis absorption.In contrast,reaction with monodentate phosphines(L_(1)-L_(5))affords trigonal planar complexes[Cu(AmIm)(L)],which are non-emissive in solution,but exhibit pronounced emission in the solid state.All ten new complexes were structurally characterised by single-crystal X-ray diffraction,enabling a direct correlation between coordination geometry and photophysical properties.Photophysical studies and TDDFT calculations reveal fluorescence in the nanosecond-range originating from ligand-to-ligand and mixed metal-ligand-to-ligand charge-transfer transitions(LL’CT,mMLL’CT).The emission properties correlate with the nature of the phosphine ligand.In particular,complexes containing chalcogen-bridged phosphines(L_(4)and L_(5))display the highest intensities and lifetimes of up to≈29.2 and≈13.9 ns,respectively.Temperature-dependent time-resolved measurements confirm prompt fluorescence and exclude thermally activated delayed fluorescence(TADF),underscoring the intrinsic nature of the emission.These results highlight the modular potential of HAmIm ligands to access structurally diverse and photoactive Cu(I)complexes with tunable solid-state emission.展开更多
Chiral 2-substituted imidazolines are not only privileged scaffolds in many bioactive compounds,but they are also widely used as ligands and catalysts in asymmetric synthesis.However,the synthesis of enantioenriched 2...Chiral 2-substituted imidazolines are not only privileged scaffolds in many bioactive compounds,but they are also widely used as ligands and catalysts in asymmetric synthesis.However,the synthesis of enantioenriched 2-substituted imidazolines is heavily relied on in step-wise synthetic approaches to chiral diamines under relatively harsh conditions.Herein,we present a highly enantioselective addition/hydroamidination of nitriles to allylamines enabled by chiral bis(oxazolinato)rare-earth metal catalysts.This protocol provides a straightforward and atom-economical route to structurally diverse enantioenriched 2-susbtituted imidazolines(in 67 examples up to 99%yield,99%ee)under mild conditions.The utility of the current method is demonstrated by the late-stage modification of complex and bioactive compounds as well as further transformations of products to other important compounds.The preliminary bioactivity study reveals that two of the new chiral imidazolines display a high inhibitory effect onlung cancer cells and hepatocellular carcinoma cells.Moreover, the possible reaction mechanism and originof enantioselectivity were elucidated based onexperimental studies and theoretical calculations.展开更多
In a groundbreaking study published in Nature,Mastrangelo et al.identified imidazole propionate(ImP),a gut microbiota-derived metabolite,as both a driver and therapeutic target in athero-sclerosis.1 This discovery ope...In a groundbreaking study published in Nature,Mastrangelo et al.identified imidazole propionate(ImP),a gut microbiota-derived metabolite,as both a driver and therapeutic target in athero-sclerosis.1 This discovery opens new avenues for early diagnosis and personalized cardiovascular treatment.展开更多
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 techniqu...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.展开更多
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 electron...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.展开更多
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...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 NaBH<sub>4</sub>.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展开更多
基金This work was supported by the National Natural Science Foundation of China （No. 30470611）the Natural Science Foundation of Zhejiang province （No.Y204133）.
文摘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.
基金Supported by the National Natural Science Foundation of China(No.51171013)
文摘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.
基金the National Natural Science Foundation of China(Project No.20102001).
文摘Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with Various substituted phenols in the presence of catalytic amount of potassium carbonate. The products are confirmed by H-1 NMR, MS, IR and elementary analysis.
基金supported by the National Natural Science Foundation of China(Nos.21262024,21062014)the Key Project of Chinese Ministry of Education(No.211193)+3 种基金the Scientific Research Foundation for Returned Scholars(Ministry of Education of China)the Natural Science Foundation of Ningxia(No.NZ1165)the Key Project of Department of Education in Ningxia(2010 Preparation of Capsaicin)the 100 Talents Program of Ningxia,and the"211"Project in Ningxia University
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China,No.81571114 and 81771267(to ZH)the National Science Funds for Distinguished Youth Scholars of China,No.81325007(to XMJ)+2 种基金the Distinguished Professor of Cheung Kong Scholars Program in China,No.T2014251(to XMJ)the Wenzhou Municipal Sci-Tec Bureau Programs in China,No.Y20120154(to ZZ) and Y20140686(to ZH)the Projects of International Cooperation and Exchanges National Natural Science Foundation of China,No.81620108011(to XMJ)
文摘We previously demonstrated that administering 2-（2-benzofuranyl）-2-imidazolin（2-BFI）, an imidazoline I2 receptor agonist, immediately after ischemia onset can protect the brain from ischemic insult. However, immediate administration after stroke is difficult to realize in the clinic. Thus, the therapeutic time window of 2-BFI should be determined. Sprague-Dawley rats provided by Wenzhou Medical University in China received right middle cerebral artery occlusion for 120 minutes, and were treated with 2-BFI（3 mg/kg） through the caudal vein at 0, 1, 3, 5, 7, and 9 hours after reperfusion. Neurological function was assessed using the Longa＇s method. Infarct volume was measured by 2,3,5-triphenyltetrazolium chloride assay. Morphological changes in the cortical penumbra were observed by hematoxylin-eosin staining under transmission electron microscopy. The apoptosis levels in the ipsilateral cortex were examined with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling（TUNEL） assay. The protein expression of Bcl-2 and BAX was detected using immunohistochemistry. We found the following： Treatment with 2-BFI within 5 hours after reperfusion obviously improved neurological function. Administering 2-BFI within 9 hours after ischemia/reperfusion decreased infarct volume and alleviated apoptosis. 2-BFI administration at different time points after reperfusion alleviated the pathological damage of the ischemic penumbra and reduced the number of apoptotic neurons, but the protective effect was more obvious when administered within 5 hours. Administration of 2-BFI within 5 hours after reperfusion remarkably increased Bcl-2 expression and decreased BAX expression. To conclude, 2-BFI shows potent neuroprotective effects when administered within 5 hours after reperfusion, seemingly by up-regulating Bcl-2 and down-regulating BAX expression. The time window provided clinical potential for ischemic stroke by 2-BFI.
文摘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.
文摘Herein we reported a one-pot synthesis of arylsubstituted imidazolin-2-ones by the cyclization of α-aminoacetophenone hydrochloride analogues 2 with arylisocyanates 3. Compared with other known synthetic route, this method resulted in higher yield.
基金Supported by Recurrent Grants from Institut National de la Santéet de la Recherche Médicale to the INSERM U1048.
文摘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.
文摘The structural properties and vibrational frequencies of 2-phenyl-2-imidazoline have been investigated using theoretical and techniques by which a good correlation was observed. The assignments of the vibrational modes were performed with the help of normal co-ordinate analysis following the Scaled Quantum Mechanical Force Field methodology. Natural bond orbital analysis and the highest occupied molecular orbital-lowest unoccupied molecular orbital gap analysis have been carried out. UV-visible spectrum of the compound was recorded and compared with the theoretical UV-visible spectrum of the title molecule using Symmetry Adapted Cluster-Configuration Interaction method which yielded good agreement. Our results reflect that the title compound can be used as good source of UV light.
基金the German Federal Environmental Foundation for financial support(DBU,AZ:20024/029)Funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)–Project Number 524554621.
文摘Amino-imidazolin-2-imines(HAmIm)are introduced as a new class of strong monoanionic N,N’-chelating ligands for Cu(I)complexes.The reaction of HAmIm with CuCl,followed by deprotonation to give AmIm−,affords the dinuclear precursor[Cu2(μ-AmIm)2],which serves as a versatile platform for the synthesis of structurally diverse mononuclear Cu(I)complexes.Coordination with diimine ligands(phenanthroline or neocuproine)yields distorted tetrahedral[Cu(AmIm)(diimine)]species featuring a broad UV/vis absorption.In contrast,reaction with monodentate phosphines(L_(1)-L_(5))affords trigonal planar complexes[Cu(AmIm)(L)],which are non-emissive in solution,but exhibit pronounced emission in the solid state.All ten new complexes were structurally characterised by single-crystal X-ray diffraction,enabling a direct correlation between coordination geometry and photophysical properties.Photophysical studies and TDDFT calculations reveal fluorescence in the nanosecond-range originating from ligand-to-ligand and mixed metal-ligand-to-ligand charge-transfer transitions(LL’CT,mMLL’CT).The emission properties correlate with the nature of the phosphine ligand.In particular,complexes containing chalcogen-bridged phosphines(L_(4)and L_(5))display the highest intensities and lifetimes of up to≈29.2 and≈13.9 ns,respectively.Temperature-dependent time-resolved measurements confirm prompt fluorescence and exclude thermally activated delayed fluorescence(TADF),underscoring the intrinsic nature of the emission.These results highlight the modular potential of HAmIm ligands to access structurally diverse and photoactive Cu(I)complexes with tunable solid-state emission.
基金support from the National Key R&D Program of China(grant no.2022YFA1504301)the National Natural Science Foundation of China(grant nos.22271199,92256303,and 92056107)the Sichuan Science and Technology Program(grant no.2023YFSY0063).
文摘Chiral 2-substituted imidazolines are not only privileged scaffolds in many bioactive compounds,but they are also widely used as ligands and catalysts in asymmetric synthesis.However,the synthesis of enantioenriched 2-substituted imidazolines is heavily relied on in step-wise synthetic approaches to chiral diamines under relatively harsh conditions.Herein,we present a highly enantioselective addition/hydroamidination of nitriles to allylamines enabled by chiral bis(oxazolinato)rare-earth metal catalysts.This protocol provides a straightforward and atom-economical route to structurally diverse enantioenriched 2-susbtituted imidazolines(in 67 examples up to 99%yield,99%ee)under mild conditions.The utility of the current method is demonstrated by the late-stage modification of complex and bioactive compounds as well as further transformations of products to other important compounds.The preliminary bioactivity study reveals that two of the new chiral imidazolines display a high inhibitory effect onlung cancer cells and hepatocellular carcinoma cells.Moreover, the possible reaction mechanism and originof enantioselectivity were elucidated based onexperimental studies and theoretical calculations.
基金support from the Chinese Scholarship Council(CSC 202308080187)D.S.acknowledges support from the IZKF SEED grant(SEED/018/23)R.G.acknowledge funding from the Deanery of the Medical Faculty of the University of Münster.
文摘In a groundbreaking study published in Nature,Mastrangelo et al.identified imidazole propionate(ImP),a gut microbiota-derived metabolite,as both a driver and therapeutic target in athero-sclerosis.1 This discovery opens new avenues for early diagnosis and personalized cardiovascular treatment.
基金This work was supported by Scientific and Technological Innovation Team for the Safety of Petroleum Tubular Goods in Southwest Petroleum University[grant number 2018CXTD01].
文摘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.
基金Financial support was provided by NSFC(21922107 and 21772171)Zhejiang Provincial Natural Science Foundation of China(LR19B020001)Center of Chemistry for Frontier Technologies,and the Fundamental Research Funds for the Central Universities(2019ONA3008).
文摘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.
文摘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 NaBH<sub>4</sub>.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
