The synthesis of 3 chloro 2 nitrotoluene using 2,6 dichloroaniline as starting material by diazotization, substitution, condensation, decarboxylic reaction was studied and the best conditions of the synthetic proc...The synthesis of 3 chloro 2 nitrotoluene using 2,6 dichloroaniline as starting material by diazotization, substitution, condensation, decarboxylic reaction was studied and the best conditions of the synthetic procedures were confirmed. Dichloronitrobenzene was obtained in 78.9% yield based on 2,6 dichloroaniline. The reaction of 2,6 dichloronitrobenzene and methyl cyanoacetate with potassium carbonate catalyst in N,N dimethyl formamide gave methyl 2 cyano 2 (3′ chloro 2′ nitrophenyl) acetate in 80.2% yield. The third procedure product 3 chloro 2 nitrophenylacetic acid was obtained by hydrolysis in 82.6% yield. Decarboxylation reaction of 3 chloro 2 nitrophenylacetic acid produced 3 chloro 2 nitrotoluene in 72.9% yield.The structure of products was identified by IR and NMR.展开更多
AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of...AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS: Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.展开更多
The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman (UVRR) spectra of 1,1'-binaphthyl-2,2'-diamine (BINAM) were measured and analyzed. Density functional theory calculations were ...The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman (UVRR) spectra of 1,1'-binaphthyl-2,2'-diamine (BINAM) were measured and analyzed. Density functional theory calculations were carried out to investigate its vibrational frequencies, infrared absorption, normal Raman, and near-resonance Raman intensities. The observed Raman and IR bands of BINAM were assigned with respect to the local vibrations of substituted 2-naphthylamine. Several Raman bands of BINAM were found selectively enhanced in the UVRR in comparison with the normal Raman spectrum. Possible excited state geometry distortion was discussed based on the resonance Raman intensity analysis.展开更多
The title compound (C6N3H18)2Ti4O4(C2O4)74H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O42H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal...The title compound (C6N3H18)2Ti4O4(C2O4)74H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O42H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal X-ray analysis has revealed that 1 crystallizes in the triclinic system, space group Pi with a = 9.1437(6), b = 11.4991(10), c = 11.6975(8) ? a = 96.2915(18), ?= 107.998(3), ? = 104.276(4), V = 1110.35(14) ?, Z = 2, Dc = 1.807 g/cm3, F(000) = 618, ?= 0.815 mm-1, the final R = 0.0463 and wR = 0.1264 for 3718 observed reflections with I > 2s(I). X-ray crystal-structure analysis suggests that compound 1 consists of [Ti4O4(C2O4)7]6- anion and two protonated N-(2-ammonioethyl)piperazinium cations. The anions are linked into an infinite chain through Ti4O4(C2O4)8 by sharing the oxalates as bridging ligands.展开更多
An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a...An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.展开更多
The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crys...The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crystal structure (C21H16N4O3, Mr = 372.38) belongs to monoclinic system, space group P21/n with a = 10.507(2), b = 16.878(3), c = 11.199(2) ? = 110.86(3), V = 1855.9(6) ?, Z = 4, Dc = 1.333 g/cm3, F(000) = 776, (MoK? = 0.092 mm-1, R = 0.0552 and wR = 0.1095 for 1920 reflections ( I > 2.0(I) ). The analytical results of crystal structure show that there are two different non-covalent interactions in the compound. One is hydrogen bond, and the other p-p stacking interaction. These two types of non-covalent interactions play an important role in the packing of crystal.展开更多
The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = ...The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often.展开更多
Cu2O and Cul were supported on multiwalled carbon nanotubes (MWCNTs) using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared sp...Cu2O and Cul were supported on multiwalled carbon nanotubes (MWCNTs) using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy, and temperature-programmed desorption with ammonia analysis. The results of these experiments revealed that Cu2O and CuI were deposited on the MWCNTs in the cubic and γ phases, respectively. These results also showed that the Cu-containing MWCNTs exhibited weak to strong electron-accepting (Lewis acidic) properties. The catalytic activities of these materials were studied for the synthesis of biologically significant N-(pyridin-2-yl)benzamides via the oxidative amidation of aryl aldehydes with 2-aminopyridines. The yields of the products were in the range 50%-95% with 100% selectivity. Notably, the CuI/MWCNT catalyst was much more effective than the Cu2O/MWCNT catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recyclability. A preferential interaction was observed between the polar nature of the acid-activated MWCNTs and the ionic Cu2O compared with covalent CuL The differences in these interactions had a significant impact on the rate of the nucleophilic attack of the amino group of 2-aminopyridine substrate on the carbonyl group of the aryl aldehyde.展开更多
Aim To develop a simple and specific high-performance liquid chromatographic(HPLC) method, suitable for the pharmacokinetic studies in vivo, to determine the concentrations of2-amino-6-cyclopropylamino-9-(2,3-dideoxy-...Aim To develop a simple and specific high-performance liquid chromatographic(HPLC) method, suitable for the pharmacokinetic studies in vivo, to determine the concentrations of2-amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuranosyl)purine (Cyclo-D4G, IMGprodrug) in rat plasma, urine and liver homogenates. Methods Chromatography was performed with C-18Hypersil ODS column and a mobile phase of 7% (v/v) acetonitrile in phosphate buffer, pH 7.40, withUV detection at 283 nm. Results The average extraction recovery of Cyclo-D4G in rat plasma and urinewas 100.1% over its linear range of 0.5 - 80 μg·mL^(-1). The accuracy of the assay was 99.4% .The intra-and inter-day RSDs were less than 9.0% . Conclusion The analytical method was found to beapplicable, reliable and suitable for pharmacokinetic studies.展开更多
A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), ...A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), c = 15.11280(10) ?, β = 108.724(2)°, V = 2190.09(7) ?3, Mr = 518.83, Z = 4, T = 293(2) K, Dc = 1.574 g/cm3, μ = 1.280 mm-1, F(000) = 1060 and S = 1.085. The final R = 0.0543 and wR = 0.1433 for 2693 observed reflections with I >2σ(I). The penta- coordinated copper (II) complex assumes an approximate square pyramidal geometry. Cyclic volta- mmetry measurement of the complex showed a quasi-reversible CuII/CuI redox couple with E1/2 = –0.467 v and ?E = 68 mv.展开更多
The reaction of di(2-pyridyl)ketone with ethylenediamine produced hexadentate Schiff base 1 which can be reduced to form a new ligand N,N-bis(di(2-pyridyl)-methyl)ethylene- diamine (BDPM) in ethanol solution. The two ...The reaction of di(2-pyridyl)ketone with ethylenediamine produced hexadentate Schiff base 1 which can be reduced to form a new ligand N,N-bis(di(2-pyridyl)-methyl)ethylene- diamine (BDPM) in ethanol solution. The two compounds were characterized by elemental analyses and spectroscopic methods. Their structures were determined by X-ray diffraction study. Crystal data for 1: C24H20N6, Mr = 392.5, monoclinic, P21/c, a = 13.871(3), b = 13.510(2), c = 12.153(2) ? b = 112.97(2)? Z = 4, V = 2094.1(6) ?, Dc = 1.245 g/cm3, m(MoKa) = 0.078 mm-1, F(000) = 824, the final R = 0.0545 and wR = 0.0557 for 2048 observed reflections (I > 2s(I)); for BDPM: C24H24N6, Mr = 396.49, monoclinic, C2/c, a = 21.411(3), b = 8.053(1), c = 11.868(1) ? b = 92.63(1)? Z = 4, V = 2044.2(4) 3, Dc = 1.288 g/cm3, m(MoKa) = 0.080 mm-1, F(000) = 840, the final R = 0.0401 and wR = 0.0939 for 1673 observed reflections (I > 2s(I)).展开更多
Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-prop...Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaffs collision factor theory. Excess isentropic compressibility is calculated from ex- perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich-Kister polynomial equation. Other proper- ties such as molecular association, available volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap- proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more -CH3 groups.展开更多
The title compound 2-[(4-methoxy-6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl]benzoic acid methyl ester (C15H16N4O6S2, Mr = 412.44) was obtained by the reaction of (4-methoxy-6-methylthio-2-pyrimidinyl)amin...The title compound 2-[(4-methoxy-6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl]benzoic acid methyl ester (C15H16N4O6S2, Mr = 412.44) was obtained by the reaction of (4-methoxy-6-methylthio-2-pyrimidinyl)amine with 2-methoxylcarbonylbenzene-sulfonylisocya- nate. The crystal is of monoclinic, space group P21/c with a =11.169(3), b = 9.508(3), c = 17.690(5) ? b = 91.593(5), Z = 4, V = 1877.9(10) 3, Dc = 1.459 g/cm3, F(000) = 856, m(MoKa) = 0.324 mm-1, R = 0.0690 and wR = 0.1368 for 3301 observed reflections (I > 2s(I)). The N(1)H…N(3) and N(2)H…O(4) hydrogen bonds can be observed. In the molecule the phenyl plane(I), pyrimi- din-2-yl-urea bridge plane(Ⅱ) and ester plane(Ⅲ) form three conjugated systems.展开更多
A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxa...A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of (110.9 ±2.3), (70.4 ± 2.1) and (61.4 ± 1.8)kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines.展开更多
2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acety...2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acetylation of N methylaniline with chloracetyl chloride, catalyzed by triethylamide with mole ratio n (C 6H 5NHCH 3)∶ n (ClCH 2C(O)Cl)∶ n (N(C 2H 5) 3)=1∶1.05∶1, the yield of 2 chloro N methyl N phenyl acetamide(Ⅰ) was 93.8%; Then the esterification of Ⅰ with anhydrous sodium acetate in the presence of phase transfer catalyst tetrabutyl ammonia bromide gave 97.3% yield of 2 acetoxyl N methyl N phenyl acetamide (Ⅱ); The ester interchange of with methanol catalyzed by potassium hydroxide gave 2 hydroxy N methyl N phenyl acetamide (Ⅲ) in 96.4% yield. And the total yield was 88.0%. IR and MS spectroscopy of products were analyzed and their characteristic peaks were assigned. Combining the results of elemental analysis, the molecular structure of Ⅰ, Ⅱ and Ⅲ was identified.展开更多
Objective The selective loss of dopaminergic neurons in Parkinson's disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stre...Objective The selective loss of dopaminergic neurons in Parkinson's disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stress. This research investigated dopamine-induced oxidative stress toxicity contributed by iron and the production of dopamine-derived neurotoxins in dopaminergic SH-SYSY cells. Methods After the SH-SYSY cells were pre-incubated with dopamine and Fe^2+ for 24 h, the cell viability, hydroxyl radical, melondialdehyde, cell apoptosis, and catechol isoquinolines were measured by lactate dehydrogenase assay, salicylic acid trapping method, thiobarbuteric acid assay, Hoechst 33258 staining and HPLC-electrochemical detection (HPLC-ECD), respectively. Results (1) Optimal dopamine (150 μmol/L) and Fe^2+ (40 or 80 μmol/L) significantly increased the concentrations of hydroxy radicals and melondialdehyde in SH-SYSY cells. (2) Induction with dopamine alone or dopamine and Fe^2+ (dopamine/Fe^2+) caused cell apoptosis. (3) Compared with untreated cells, the catechol isoquinolines, salsolinol and N-methyl-salsolinol in dopamine/Fe^2+-induced cells were detected in increasing amounts. Conclusion Due to dopamine/Fe^2+-induced oxidative stress similar to the state in the parkinsonian substantia nigra neurons, dopamine and Fe^2+ impaired SH-SYSY cells could be used as the cell oxidative stress model of Parkinson's disease. The catechol isoquinolines detected in cells may be involved in the pathogenesis of Parkinson's disease as potential neurotoxins.展开更多
The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and mic...The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.展开更多
3-Sulfenylindoles are widely found in natural products,bioactive molecules and organic functional materials.BF_(3)·OEt_(2)mediated electrophilic cyclization reaction of 2-alkynylaniline with N-(arylthio)succinimi...3-Sulfenylindoles are widely found in natural products,bioactive molecules and organic functional materials.BF_(3)·OEt_(2)mediated electrophilic cyclization reaction of 2-alkynylaniline with N-(arylthio)succinimide was developed leading to the efficient synthesis of various biologically active 3-sulfenylindoles in moderate to high yields under very mild conditions.This protocol has the advantages of broad scope,functional group diversity,mild conditions and ease of operation.Moreover,gram-scale preparation portends the practical application.展开更多
The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18...The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18. 330(2) A, β=97. 36(1 )°, V= 2l08. 5(4) A 3, Z= 4, D.= l. 280 g/cm3, F(000) = 864, μ=O. O88mm-1 and final R= O. O368, wR(F2) = 0.0787 for reflections (I>2σ(I) ). X-ray anal-ysis reveals that the crystal is composed of a pair of enantiomer, and there are hydrogenbonds O(3) -H(3O) -N(l ) between the two enantimers. There are two planes in themolecule.展开更多
文摘The synthesis of 3 chloro 2 nitrotoluene using 2,6 dichloroaniline as starting material by diazotization, substitution, condensation, decarboxylic reaction was studied and the best conditions of the synthetic procedures were confirmed. Dichloronitrobenzene was obtained in 78.9% yield based on 2,6 dichloroaniline. The reaction of 2,6 dichloronitrobenzene and methyl cyanoacetate with potassium carbonate catalyst in N,N dimethyl formamide gave methyl 2 cyano 2 (3′ chloro 2′ nitrophenyl) acetate in 80.2% yield. The third procedure product 3 chloro 2 nitrophenylacetic acid was obtained by hydrolysis in 82.6% yield. Decarboxylation reaction of 3 chloro 2 nitrophenylacetic acid produced 3 chloro 2 nitrotoluene in 72.9% yield.The structure of products was identified by IR and NMR.
基金Supported by National Natural Science Foundation of China, No. 30570665the Foundation of Dalian Technology Bureau, No. 2008E13SF182the Foundation of Key Laboratory of Education Department of Liaoning Province,No. 2009S005
文摘AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS: Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.
基金This work was supported by the National Natural Science Foundation of China (No.21273211, No.21573208), USTC-NSRL Association Foundation (No.NSRLLHJJ(14-15-012), and the Supercomputation Center of USTC.
文摘The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman (UVRR) spectra of 1,1'-binaphthyl-2,2'-diamine (BINAM) were measured and analyzed. Density functional theory calculations were carried out to investigate its vibrational frequencies, infrared absorption, normal Raman, and near-resonance Raman intensities. The observed Raman and IR bands of BINAM were assigned with respect to the local vibrations of substituted 2-naphthylamine. Several Raman bands of BINAM were found selectively enhanced in the UVRR in comparison with the normal Raman spectrum. Possible excited state geometry distortion was discussed based on the resonance Raman intensity analysis.
基金This work was supported by the Natural Science Foundation of Fujian Province (No. E0110013 and K02028) and the State Key Laboratory of Structural Chemistry
文摘The title compound (C6N3H18)2Ti4O4(C2O4)74H2O 1 (C13H22N3O18Ti2, Mr = 604.14) was synthesized by the reaction of Ti(SO4)2, H2C2O42H2O and N-(2-ammonioethyl)- piperazinium (AEPP) in aqueous solution. The single-crystal X-ray analysis has revealed that 1 crystallizes in the triclinic system, space group Pi with a = 9.1437(6), b = 11.4991(10), c = 11.6975(8) ? a = 96.2915(18), ?= 107.998(3), ? = 104.276(4), V = 1110.35(14) ?, Z = 2, Dc = 1.807 g/cm3, F(000) = 618, ?= 0.815 mm-1, the final R = 0.0463 and wR = 0.1264 for 3718 observed reflections with I > 2s(I). X-ray crystal-structure analysis suggests that compound 1 consists of [Ti4O4(C2O4)7]6- anion and two protonated N-(2-ammonioethyl)piperazinium cations. The anions are linked into an infinite chain through Ti4O4(C2O4)8 by sharing the oxalates as bridging ligands.
基金supported by the Intercollegiate Key Scientific Research Projects of Henan Province(15A150018)~~
文摘An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.
文摘The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crystal structure (C21H16N4O3, Mr = 372.38) belongs to monoclinic system, space group P21/n with a = 10.507(2), b = 16.878(3), c = 11.199(2) ? = 110.86(3), V = 1855.9(6) ?, Z = 4, Dc = 1.333 g/cm3, F(000) = 776, (MoK? = 0.092 mm-1, R = 0.0552 and wR = 0.1095 for 1920 reflections ( I > 2.0(I) ). The analytical results of crystal structure show that there are two different non-covalent interactions in the compound. One is hydrogen bond, and the other p-p stacking interaction. These two types of non-covalent interactions play an important role in the packing of crystal.
文摘The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often.
基金DST-SERB for the financial support for this research work(Project number:SERB/F/3690/2013-14)
文摘Cu2O and Cul were supported on multiwalled carbon nanotubes (MWCNTs) using a wet impregna- tion method, and the resulting materials were fully characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, transmission electron microscopy, and temperature-programmed desorption with ammonia analysis. The results of these experiments revealed that Cu2O and CuI were deposited on the MWCNTs in the cubic and γ phases, respectively. These results also showed that the Cu-containing MWCNTs exhibited weak to strong electron-accepting (Lewis acidic) properties. The catalytic activities of these materials were studied for the synthesis of biologically significant N-(pyridin-2-yl)benzamides via the oxidative amidation of aryl aldehydes with 2-aminopyridines. The yields of the products were in the range 50%-95% with 100% selectivity. Notably, the CuI/MWCNT catalyst was much more effective than the Cu2O/MWCNT catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recyclability. A preferential interaction was observed between the polar nature of the acid-activated MWCNTs and the ionic Cu2O compared with covalent CuL The differences in these interactions had a significant impact on the rate of the nucleophilic attack of the amino group of 2-aminopyridine substrate on the carbonyl group of the aryl aldehyde.
文摘Aim To develop a simple and specific high-performance liquid chromatographic(HPLC) method, suitable for the pharmacokinetic studies in vivo, to determine the concentrations of2-amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuranosyl)purine (Cyclo-D4G, IMGprodrug) in rat plasma, urine and liver homogenates. Methods Chromatography was performed with C-18Hypersil ODS column and a mobile phase of 7% (v/v) acetonitrile in phosphate buffer, pH 7.40, withUV detection at 283 nm. Results The average extraction recovery of Cyclo-D4G in rat plasma and urinewas 100.1% over its linear range of 0.5 - 80 μg·mL^(-1). The accuracy of the assay was 99.4% .The intra-and inter-day RSDs were less than 9.0% . Conclusion The analytical method was found to beapplicable, reliable and suitable for pharmacokinetic studies.
基金This project was supported by "973" program of the Ministry of Science and Technology ofChina and National Natural Science Foundation of China (20376010 20128005)
文摘A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), c = 15.11280(10) ?, β = 108.724(2)°, V = 2190.09(7) ?3, Mr = 518.83, Z = 4, T = 293(2) K, Dc = 1.574 g/cm3, μ = 1.280 mm-1, F(000) = 1060 and S = 1.085. The final R = 0.0543 and wR = 0.1433 for 2693 observed reflections with I >2σ(I). The penta- coordinated copper (II) complex assumes an approximate square pyramidal geometry. Cyclic volta- mmetry measurement of the complex showed a quasi-reversible CuII/CuI redox couple with E1/2 = –0.467 v and ?E = 68 mv.
基金This work was financially supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars State Educational Ministry
文摘The reaction of di(2-pyridyl)ketone with ethylenediamine produced hexadentate Schiff base 1 which can be reduced to form a new ligand N,N-bis(di(2-pyridyl)-methyl)ethylene- diamine (BDPM) in ethanol solution. The two compounds were characterized by elemental analyses and spectroscopic methods. Their structures were determined by X-ray diffraction study. Crystal data for 1: C24H20N6, Mr = 392.5, monoclinic, P21/c, a = 13.871(3), b = 13.510(2), c = 12.153(2) ? b = 112.97(2)? Z = 4, V = 2094.1(6) ?, Dc = 1.245 g/cm3, m(MoKa) = 0.078 mm-1, F(000) = 824, the final R = 0.0545 and wR = 0.0557 for 2048 observed reflections (I > 2s(I)); for BDPM: C24H24N6, Mr = 396.49, monoclinic, C2/c, a = 21.411(3), b = 8.053(1), c = 11.868(1) ? b = 92.63(1)? Z = 4, V = 2044.2(4) 3, Dc = 1.288 g/cm3, m(MoKa) = 0.080 mm-1, F(000) = 840, the final R = 0.0401 and wR = 0.0939 for 1673 observed reflections (I > 2s(I)).
文摘Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaffs collision factor theory. Excess isentropic compressibility is calculated from ex- perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich-Kister polynomial equation. Other proper- ties such as molecular association, available volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap- proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more -CH3 groups.
基金The project was supported by the National Natural Science Foundation of China (20372021) and Natural Science Foundation of Hunan Province (03JJY3018)
文摘The title compound 2-[(4-methoxy-6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl]benzoic acid methyl ester (C15H16N4O6S2, Mr = 412.44) was obtained by the reaction of (4-methoxy-6-methylthio-2-pyrimidinyl)amine with 2-methoxylcarbonylbenzene-sulfonylisocya- nate. The crystal is of monoclinic, space group P21/c with a =11.169(3), b = 9.508(3), c = 17.690(5) ? b = 91.593(5), Z = 4, V = 1877.9(10) 3, Dc = 1.459 g/cm3, F(000) = 856, m(MoKa) = 0.324 mm-1, R = 0.0690 and wR = 0.1368 for 3301 observed reflections (I > 2s(I)). The N(1)H…N(3) and N(2)H…O(4) hydrogen bonds can be observed. In the molecule the phenyl plane(I), pyrimi- din-2-yl-urea bridge plane(Ⅱ) and ester plane(Ⅲ) form three conjugated systems.
基金Supported by the National Natural Science Foundation of China(21176218)Zhejiang Key Innovation Team of Green Pharmaceutical Technology(2010R50043)
文摘A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of (110.9 ±2.3), (70.4 ± 2.1) and (61.4 ± 1.8)kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines.
文摘2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acetylation of N methylaniline with chloracetyl chloride, catalyzed by triethylamide with mole ratio n (C 6H 5NHCH 3)∶ n (ClCH 2C(O)Cl)∶ n (N(C 2H 5) 3)=1∶1.05∶1, the yield of 2 chloro N methyl N phenyl acetamide(Ⅰ) was 93.8%; Then the esterification of Ⅰ with anhydrous sodium acetate in the presence of phase transfer catalyst tetrabutyl ammonia bromide gave 97.3% yield of 2 acetoxyl N methyl N phenyl acetamide (Ⅱ); The ester interchange of with methanol catalyzed by potassium hydroxide gave 2 hydroxy N methyl N phenyl acetamide (Ⅲ) in 96.4% yield. And the total yield was 88.0%. IR and MS spectroscopy of products were analyzed and their characteristic peaks were assigned. Combining the results of elemental analysis, the molecular structure of Ⅰ, Ⅱ and Ⅲ was identified.
基金This work was supported by the National Natural Science Foundation of China (No. 20435020, No. 20275005, and No. 30670645).
文摘Objective The selective loss of dopaminergic neurons in Parkinson's disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stress. This research investigated dopamine-induced oxidative stress toxicity contributed by iron and the production of dopamine-derived neurotoxins in dopaminergic SH-SYSY cells. Methods After the SH-SYSY cells were pre-incubated with dopamine and Fe^2+ for 24 h, the cell viability, hydroxyl radical, melondialdehyde, cell apoptosis, and catechol isoquinolines were measured by lactate dehydrogenase assay, salicylic acid trapping method, thiobarbuteric acid assay, Hoechst 33258 staining and HPLC-electrochemical detection (HPLC-ECD), respectively. Results (1) Optimal dopamine (150 μmol/L) and Fe^2+ (40 or 80 μmol/L) significantly increased the concentrations of hydroxy radicals and melondialdehyde in SH-SYSY cells. (2) Induction with dopamine alone or dopamine and Fe^2+ (dopamine/Fe^2+) caused cell apoptosis. (3) Compared with untreated cells, the catechol isoquinolines, salsolinol and N-methyl-salsolinol in dopamine/Fe^2+-induced cells were detected in increasing amounts. Conclusion Due to dopamine/Fe^2+-induced oxidative stress similar to the state in the parkinsonian substantia nigra neurons, dopamine and Fe^2+ impaired SH-SYSY cells could be used as the cell oxidative stress model of Parkinson's disease. The catechol isoquinolines detected in cells may be involved in the pathogenesis of Parkinson's disease as potential neurotoxins.
基金Project(51474253)supported by the National Natural Science Foundation of China。
文摘The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.
文摘3-Sulfenylindoles are widely found in natural products,bioactive molecules and organic functional materials.BF_(3)·OEt_(2)mediated electrophilic cyclization reaction of 2-alkynylaniline with N-(arylthio)succinimide was developed leading to the efficient synthesis of various biologically active 3-sulfenylindoles in moderate to high yields under very mild conditions.This protocol has the advantages of broad scope,functional group diversity,mild conditions and ease of operation.Moreover,gram-scale preparation portends the practical application.
文摘The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18. 330(2) A, β=97. 36(1 )°, V= 2l08. 5(4) A 3, Z= 4, D.= l. 280 g/cm3, F(000) = 864, μ=O. O88mm-1 and final R= O. O368, wR(F2) = 0.0787 for reflections (I>2σ(I) ). X-ray anal-ysis reveals that the crystal is composed of a pair of enantiomer, and there are hydrogenbonds O(3) -H(3O) -N(l ) between the two enantimers. There are two planes in themolecule.