Kinetics of the coordination reaction of tetrakis(Ncarbomethoxymethyl3pyridyl) porphyrin(abbr. H2TβNACMSPyP) with Cu?ion has been studied in ophthalic acid buffer system in an ionic strength of 0.5mol...Kinetics of the coordination reaction of tetrakis(Ncarbomethoxymethyl3pyridyl) porphyrin(abbr. H2TβNACMSPyP) with Cu?ion has been studied in ophthalic acid buffer system in an ionic strength of 0.5mol·dm-3(KCI) at 35.0±0.1℃.The reaction is catalyzed by ophthalic ion. The effect of concentration of the catalyst, metal ion and pH value of solution was discussed. The kinetics equation of the reaction were obtained as d/dt=16.15{(1.0+3.35×1052)/1.0+1.57×10-42}T. The mechanism of the reaction was proposed. The deformation of the ring of porphyrins is the general condition in the reaction. Keyowrds:展开更多
标题化合物C24H26O5是由胡椒醛、达咪酮在微波辐射下反应而得,反应在5分钟内完成。结构通过单晶 X-射线衍射法测定,其晶体属三斜晶系,空间群P, a = 7.1338(1), b = 10.4406 (3), c = 14.3323(4) , a = 82.56(1), b = 89.37(1), g = 78.9...标题化合物C24H26O5是由胡椒醛、达咪酮在微波辐射下反应而得,反应在5分钟内完成。结构通过单晶 X-射线衍射法测定,其晶体属三斜晶系,空间群P, a = 7.1338(1), b = 10.4406 (3), c = 14.3323(4) , a = 82.56(1), b = 89.37(1), g = 78.94(1), V = 1038.73(4) 3, Mr = 394.45, Z = 2, Dc = 1.261 g/cm3, l = 0.71073 ? m(MoKa) = 0.088 mm-1, F(000) = 420, R = 0.0648, wR = 0.1588。在分子结构中吡喃环为船式构象,2个的环己酮环为信封式结构。展开更多
通过荧光光谱法研究了铕(Ⅲ)、铽(Ⅲ)两种稀土离子对四(3,4-亚甲二氧基苯基)卟啉(T M PP)荧光强度的影响。在中性介质中,铕(Ⅲ)和铽(Ⅲ)与T M PP相互作用使T M P P的荧光猝灭。实验表明:以DMF为溶剂、420 nm为最大激发波长、655nm为最...通过荧光光谱法研究了铕(Ⅲ)、铽(Ⅲ)两种稀土离子对四(3,4-亚甲二氧基苯基)卟啉(T M PP)荧光强度的影响。在中性介质中,铕(Ⅲ)和铽(Ⅲ)与T M PP相互作用使T M P P的荧光猝灭。实验表明:以DMF为溶剂、420 nm为最大激发波长、655nm为最大发射波长时,T MPP的荧光强度和稀土离子对其荧光猝灭均达到最大值。展开更多
Conversion of cellulose into platform chemical 5-hydroxymethylfurfural （HMF） in water-tetrahydrofuran （THF） co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentratio...Conversion of cellulose into platform chemical 5-hydroxymethylfurfural （HMF） in water-tetrahydrofuran （THF） co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentration of 2.4wt%, but levulinic acid （LA） and solid humins became the main products with high cellulose concentration. The soluble byproducts were analyzed by high performance liquid chromatography/multiple stage tandem mass spec-trometry, and chemicals with formula of C9H16O4、 C10H14O4、 C11H12O4、C12H10O5 and C12H16O8 were detected. THF could participate in the reaction via ring-opening into 1,4-butanediol followed by esterification with LA into C9H16O4 or etherification with HMF into C10H14O4. C11H12O4 was formed by esterification of HMF with LA, C12H10O5 was formed by self-etherification of HMF, while C12H16O8 was formed by acetalization of HMF with glucose. Self-etherification of HMF and etherification of HMF with 1,4-butanediol were identified as two main side reactions.展开更多
Aim To observe the neuroprotective effects of modafinil on the Parkinson'sdisease ( PD ) model induced by 1-methyl-4-phenyl-1, 2,3, 6-tetrahydropyridine (MPTP ). Methods Themodel of PD was induced by intraperitone...Aim To observe the neuroprotective effects of modafinil on the Parkinson'sdisease ( PD ) model induced by 1-methyl-4-phenyl-1, 2,3, 6-tetrahydropyridine (MPTP ). Methods Themodel of PD was induced by intraperitoneal injection of MPTP into C57BL/6J mice for 4 d. Modafinil(ip, 50 or 100 mg·kg^(-1)·d^(-1)) was administered following MPTP for 4 d and for another 10 dconsecatirely. The effects of modafinil on the locomotor activity, and the incubation, maintenanceperiod and grade of the tremor, the duration of the climbing rod of mouse, and the distribution ofpositive cells of ty-rosine hydroxylase (TH) and Nissl bodies in the striatum and substantia nigra(SN) were observed. The contents of dopam-ine (DA) , noradrenaline (NA) and 5-hydroxytryptamine(5-HT) in the striatum were determined. Results Modafinil (50 and 100 mg·kg^(-1)) significantlyprevented the locomotor, the tremor and climbing rod defect behavior in a dose-dependent manner (P <0.05 and P < 0.01, n = 10), prevented the decrease in the number of TH-positive cells and Nisslbodies (P<0.05, n=10), and reduced the decrease of DA, NA, and 5-HT in the striatum (P < 0.05, n =10) induced by MPTP. Conclusion Modafinil improves the behavioral deficits and prevents themonoaminergic neuron lesion in seriously impaired MPTP mouse model.展开更多
A novel p‐n heterostructure photocatalyst m‐Bi2O4/BiOCl was successfully synthetized through a facile ion‐etching method.Via adjusting the added volume of HCl solution,a series of different ratios of composite phot...A novel p‐n heterostructure photocatalyst m‐Bi2O4/BiOCl was successfully synthetized through a facile ion‐etching method.Via adjusting the added volume of HCl solution,a series of different ratios of composite photocatalysts were obtained.The as‐prepared samples of physical,chemical and optical characteristics were examined by X‐ray diffraction,scanning electron microscope,transmission electron microscope,energy dispersive X‐ray spectroscopy,selected‐area electron diffraction,Fourier transform infrared absorption,Raman microscope,N2 adsorption‐desorption,X‐ray photoelectron spectroscopy and UV‐vis spectrum technologies.The photocatalysts showed high degradation rate and complete mineralization ability for methyl orange and tetracycline solution under visible light.The reaction rate constant of m‐Bi2O4/BiOCl for methyl orange was 52.28 times higher than that of BiOCl.The characterization presented a good stability of materials.Furthermore,the photocurrent response test certified that the heterostructure effectively accelerated the separation and migration of photo‐generated carries.The scavenger experiments evidenced that hole(h+)and superoxide radical(?O2?)were the primary active radicals.A possible photocatalytic mechanism was proposed.This work provided an alternative photocatalyst applied to water environmental remediation.展开更多
Tetra-hydroxymethyl phosphonium chloride （THPC） has been considered as an important chrome-free tanning agent. To understand the THPC tanning mechanism, the structure, charge distribution, activity and tanning abili...Tetra-hydroxymethyl phosphonium chloride （THPC） has been considered as an important chrome-free tanning agent. To understand the THPC tanning mechanism, the structure, charge distribution, activity and tanning ability of each phosphorous compound in THPC tanning system were studied, by ^31p NMR, FT-IR spectroscopy, differential scanning calorimetry （DSC） and computational chemistry method, etc. When pH raised to 6.0, the decomposition of THPC would take place, which results in a production of free formaldehyde, tri-hydroxymethyl phosphonium （TrHP） and tri-hydroxymethyl phosphine oxide （TrHPO）. At pH 9.0, THPC will be converted completely to TrHP and most TrHP is further oxidized into TrHPO. It is possible that, in reaction of phosphorous compounds and collagens, both P-C and C-O bonds would break simultaneously or individually. From molecular charge distribution and bond polar properties, it is deduced that, if P-C bonds break, the activity is in order of TrHPO 〉 THPC 〉 TrHE whereas if C--O bonds break, the order is TrHP 〉 THPC 〉 TrHPO. It is more possible that P--C bonds will break in reaction with collagen, and TrHPO may be more active in the THPC tanning system. The results of tanning and DSC also prove the above conclusion. Furthermore, the fact that the shrinkage temperature of THPC tanned leather was below 70℃ when basified to pH 5.0 or lower suggests that the hydroxymethyl groups of THPC and TrHP are less possible to combine directly with amino groups of collagen.展开更多
AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS： Th...AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS： The short-circuit current （Isc） technique in conjunction with pharmacological agents and specific inhibitors were used in analyzing the electrolyte transport across the distal colon of rodents. The underlying cellular signaling mechanism was investigated by radioimmunoassay analysis （RIA） and a special mouse model of cystic fibrosis.RESULTS： IMP stimulated a conoentration-dependent rise in ISCl, which was dependent on both Cl^- and HCO3^-, and inhibited by apical application of diphenylamine-2,2＇-dicarboxylic acid （DPC） and glibenclamide, but resistant to 4,4＇-diisothiocyanatostilbene-2,2＇-disulfonic acid disodium salt hydrate （DIDS）. Removal of Na^＋ from basolateral solution almost completely abolished the Isc response to TMP, but it was insensitive to apical Na^＋ replacement or apical Na^＋ channel blocker, amiloride. Pretreatment of colonic mucosa with BAPTA-AM, a membrane-permeable selective Ca2＋ chelator, did not significantly alter the TMP-induced Iso No additive effect of forskolin and 3-isobutyl-l-methylxanthine （[BMX） was observed on the TMP-induced Isc, but it was significantly reduced by a protein kinase A inhibitor, H89.RIA results showed that TMP （1 mmol/L） elicited a significant increase in cellular cAMP production, which was similar to that elicited by the adenylate cyclase activator, forskolin （10μmol/L）. The TMP-elicited Isc as well as forskolin- or IBMX-induced Isc were abolished in mice with homozygous mutation of the cystic fibrosis transmembrane conductance regulator （CFTR） presenting defective CFTR functions and secretions.CONCLUSION： TMP may stimulate cAMP-dependent and CFTR-mediated Cl^- and HCO3^- secretion. This may have implications in the future development of alternative treatment for constipation.展开更多
文摘Kinetics of the coordination reaction of tetrakis(Ncarbomethoxymethyl3pyridyl) porphyrin(abbr. H2TβNACMSPyP) with Cu?ion has been studied in ophthalic acid buffer system in an ionic strength of 0.5mol·dm-3(KCI) at 35.0±0.1℃.The reaction is catalyzed by ophthalic ion. The effect of concentration of the catalyst, metal ion and pH value of solution was discussed. The kinetics equation of the reaction were obtained as d/dt=16.15{(1.0+3.35×1052)/1.0+1.57×10-42}T. The mechanism of the reaction was proposed. The deformation of the ring of porphyrins is the general condition in the reaction. Keyowrds:
文摘标题化合物C24H26O5是由胡椒醛、达咪酮在微波辐射下反应而得,反应在5分钟内完成。结构通过单晶 X-射线衍射法测定,其晶体属三斜晶系,空间群P, a = 7.1338(1), b = 10.4406 (3), c = 14.3323(4) , a = 82.56(1), b = 89.37(1), g = 78.94(1), V = 1038.73(4) 3, Mr = 394.45, Z = 2, Dc = 1.261 g/cm3, l = 0.71073 ? m(MoKa) = 0.088 mm-1, F(000) = 420, R = 0.0648, wR = 0.1588。在分子结构中吡喃环为船式构象,2个的环己酮环为信封式结构。
文摘通过荧光光谱法研究了铕(Ⅲ)、铽(Ⅲ)两种稀土离子对四(3,4-亚甲二氧基苯基)卟啉(T M PP)荧光强度的影响。在中性介质中,铕(Ⅲ)和铽(Ⅲ)与T M PP相互作用使T M P P的荧光猝灭。实验表明:以DMF为溶剂、420 nm为最大激发波长、655nm为最大发射波长时,T MPP的荧光强度和稀土离子对其荧光猝灭均达到最大值。
基金This work was supported by the National Basic Research Program of China （No.2012CB215304）, the National Natural Science Foundation of China （No.51376185 and No.51161140331）, and the Natural Science Foundation of Guangdong Province （No.S2013010011612）.
文摘Conversion of cellulose into platform chemical 5-hydroxymethylfurfural （HMF） in water-tetrahydrofuran （THF） co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentration of 2.4wt%, but levulinic acid （LA） and solid humins became the main products with high cellulose concentration. The soluble byproducts were analyzed by high performance liquid chromatography/multiple stage tandem mass spec-trometry, and chemicals with formula of C9H16O4、 C10H14O4、 C11H12O4、C12H10O5 and C12H16O8 were detected. THF could participate in the reaction via ring-opening into 1,4-butanediol followed by esterification with LA into C9H16O4 or etherification with HMF into C10H14O4. C11H12O4 was formed by esterification of HMF with LA, C12H10O5 was formed by self-etherification of HMF, while C12H16O8 was formed by acetalization of HMF with glucose. Self-etherification of HMF and etherification of HMF with 1,4-butanediol were identified as two main side reactions.
文摘Aim To observe the neuroprotective effects of modafinil on the Parkinson'sdisease ( PD ) model induced by 1-methyl-4-phenyl-1, 2,3, 6-tetrahydropyridine (MPTP ). Methods Themodel of PD was induced by intraperitoneal injection of MPTP into C57BL/6J mice for 4 d. Modafinil(ip, 50 or 100 mg·kg^(-1)·d^(-1)) was administered following MPTP for 4 d and for another 10 dconsecatirely. The effects of modafinil on the locomotor activity, and the incubation, maintenanceperiod and grade of the tremor, the duration of the climbing rod of mouse, and the distribution ofpositive cells of ty-rosine hydroxylase (TH) and Nissl bodies in the striatum and substantia nigra(SN) were observed. The contents of dopam-ine (DA) , noradrenaline (NA) and 5-hydroxytryptamine(5-HT) in the striatum were determined. Results Modafinil (50 and 100 mg·kg^(-1)) significantlyprevented the locomotor, the tremor and climbing rod defect behavior in a dose-dependent manner (P <0.05 and P < 0.01, n = 10), prevented the decrease in the number of TH-positive cells and Nisslbodies (P<0.05, n=10), and reduced the decrease of DA, NA, and 5-HT in the striatum (P < 0.05, n =10) induced by MPTP. Conclusion Modafinil improves the behavioral deficits and prevents themonoaminergic neuron lesion in seriously impaired MPTP mouse model.
基金supported by the National Natural Science Foundation of China(51578354)Suzhou Science and Technology Bureau(SS201667)+1 种基金Six Talent Peaks Program(2016-JNHB-067)Qing Lan Project of Jiangsu Province~~
文摘A novel p‐n heterostructure photocatalyst m‐Bi2O4/BiOCl was successfully synthetized through a facile ion‐etching method.Via adjusting the added volume of HCl solution,a series of different ratios of composite photocatalysts were obtained.The as‐prepared samples of physical,chemical and optical characteristics were examined by X‐ray diffraction,scanning electron microscope,transmission electron microscope,energy dispersive X‐ray spectroscopy,selected‐area electron diffraction,Fourier transform infrared absorption,Raman microscope,N2 adsorption‐desorption,X‐ray photoelectron spectroscopy and UV‐vis spectrum technologies.The photocatalysts showed high degradation rate and complete mineralization ability for methyl orange and tetracycline solution under visible light.The reaction rate constant of m‐Bi2O4/BiOCl for methyl orange was 52.28 times higher than that of BiOCl.The characterization presented a good stability of materials.Furthermore,the photocurrent response test certified that the heterostructure effectively accelerated the separation and migration of photo‐generated carries.The scavenger experiments evidenced that hole(h+)and superoxide radical(?O2?)were the primary active radicals.A possible photocatalytic mechanism was proposed.This work provided an alternative photocatalyst applied to water environmental remediation.
基金the National Basic Research Program (2007CB616909)Startup Foundation of Applied Chemistry of the Key Discipline of Zhejiang University of Technology and Zhejiang Provincial Science and Technology Plan (2006C21107)
文摘Tetra-hydroxymethyl phosphonium chloride （THPC） has been considered as an important chrome-free tanning agent. To understand the THPC tanning mechanism, the structure, charge distribution, activity and tanning ability of each phosphorous compound in THPC tanning system were studied, by ^31p NMR, FT-IR spectroscopy, differential scanning calorimetry （DSC） and computational chemistry method, etc. When pH raised to 6.0, the decomposition of THPC would take place, which results in a production of free formaldehyde, tri-hydroxymethyl phosphonium （TrHP） and tri-hydroxymethyl phosphine oxide （TrHPO）. At pH 9.0, THPC will be converted completely to TrHP and most TrHP is further oxidized into TrHPO. It is possible that, in reaction of phosphorous compounds and collagens, both P-C and C-O bonds would break simultaneously or individually. From molecular charge distribution and bond polar properties, it is deduced that, if P-C bonds break, the activity is in order of TrHPO 〉 THPC 〉 TrHE whereas if C--O bonds break, the order is TrHP 〉 THPC 〉 TrHPO. It is more possible that P--C bonds will break in reaction with collagen, and TrHPO may be more active in the THPC tanning system. The results of tanning and DSC also prove the above conclusion. Furthermore, the fact that the shrinkage temperature of THPC tanned leather was below 70℃ when basified to pH 5.0 or lower suggests that the hydroxymethyl groups of THPC and TrHP are less possible to combine directly with amino groups of collagen.
基金Supported by the Innovation and Technology Fund of Hong Kong, China
文摘AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS： The short-circuit current （Isc） technique in conjunction with pharmacological agents and specific inhibitors were used in analyzing the electrolyte transport across the distal colon of rodents. The underlying cellular signaling mechanism was investigated by radioimmunoassay analysis （RIA） and a special mouse model of cystic fibrosis.RESULTS： IMP stimulated a conoentration-dependent rise in ISCl, which was dependent on both Cl^- and HCO3^-, and inhibited by apical application of diphenylamine-2,2＇-dicarboxylic acid （DPC） and glibenclamide, but resistant to 4,4＇-diisothiocyanatostilbene-2,2＇-disulfonic acid disodium salt hydrate （DIDS）. Removal of Na^＋ from basolateral solution almost completely abolished the Isc response to TMP, but it was insensitive to apical Na^＋ replacement or apical Na^＋ channel blocker, amiloride. Pretreatment of colonic mucosa with BAPTA-AM, a membrane-permeable selective Ca2＋ chelator, did not significantly alter the TMP-induced Iso No additive effect of forskolin and 3-isobutyl-l-methylxanthine （[BMX） was observed on the TMP-induced Isc, but it was significantly reduced by a protein kinase A inhibitor, H89.RIA results showed that TMP （1 mmol/L） elicited a significant increase in cellular cAMP production, which was similar to that elicited by the adenylate cyclase activator, forskolin （10μmol/L）. The TMP-elicited Isc as well as forskolin- or IBMX-induced Isc were abolished in mice with homozygous mutation of the cystic fibrosis transmembrane conductance regulator （CFTR） presenting defective CFTR functions and secretions.CONCLUSION： TMP may stimulate cAMP-dependent and CFTR-mediated Cl^- and HCO3^- secretion. This may have implications in the future development of alternative treatment for constipation.
