Natural products are the important sources in cardiovascular drug development.In this study,twenty-nine buthutin derivatives were designed,synthesized,and evaluated for their NHE-1 inhibition and protective effects on...Natural products are the important sources in cardiovascular drug development.In this study,twenty-nine buthutin derivatives were designed,synthesized,and evaluated for their NHE-1 inhibition and protective effects on cardiomyo-cyte injury.The structure of the newly synthesized compounds had been confirmed by 1H-NMR,13C-NMR,and HR-ESI-MS spectra.Among all target compounds at 1μM,compounds 9d,9f,9k,9m,and 9n,with a protection ratio exceeding 30%,exerted stronger protective effects on H9c2 cardiomyocyte than positive control dexrazoxane and buthutin A.Meanwhile,compounds 9k,9m,and 9o showed the significant NHE-1 inhibitory activities on H9c2 cardiomyocyte,all with a dpHi/min value less than 0.23.What is more,compounds 9k,9m,9o and buthutin A all exhibited the specificity on NHE-1 inhibition.Molecular modelling studies suggested the ability of compounds 9m and 9o to establish interactions with three hydrogen bonds to Asp267 and Glu346 of NHE-1,but also the ability with much lower CDOCKER energies than positive control cariporide and buthutin A.The structure-activity relationship(SAR)studies suggested that the presences of amide group,four-carbon linker,and para hydroxyl benzene ring were advantageous pharmacophores for above two pharmacological actions.This research would open new avenues for developing amide-guanidine-based cardioprotective agents.展开更多
Objective To prepare artificial antigens and anti-citrinin egg yolk-derived immunoglobulin （IgY） to build an enzyme-linked immunosorbent assay （ELISA） for citrinin （CTN）. Methods CTN was conjugated with bovine s...Objective To prepare artificial antigens and anti-citrinin egg yolk-derived immunoglobulin （IgY） to build an enzyme-linked immunosorbent assay （ELISA） for citrinin （CTN）. Methods CTN was conjugated with bovine serum albumin （BSA）, ovalbumin （OVA） with formaldehyde condensation method to prepare artificial antigens and identified by ultraviolet （UV） spectrometry and Infrared （IR） spectrometry. Artificial antigens for CTN and anti-CTN IgY were purified with polyethylene glycol two-step precipitation method and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. ELISA with IgY was established. Cross-reactivity of IgY with various structural similarities to CTN and possible co-occurrence with CTN in agricultural commodities were studied. Results UV and IR absorption spectra suggested that CTN was correlated with the carrier protein of BSA or OVA. SDS-PAGE patterns showed that the anti-CTN IgY was almost pure with a molecular weight of approximate 100 KD. The indirect competitive ELISA showed that the detection limit of CTN was 10 ng·mL^-1, with a good linearity ranging 20-640 ng·mL^-1. Conclusion Artificial antigens of CTN can be successfully synthesized. The established ELISA can be used to determine CTN- contaminated samples.展开更多
A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse is...A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse isocyanates in the presence of sodium hydride. The easy availability of substrates and tolerance of structural diversity in this reaction make it attractive to be used for construction of libraries in drug discovery process.展开更多
A facile and efficient protocol was developed to access 2-alkoxy-4-amino-N-arylthiazole-5-carbox- amides through a three-component one-pot reaction, which involved potassium methyl cyanimido- dithiocarbonate, 2-halo-N...A facile and efficient protocol was developed to access 2-alkoxy-4-amino-N-arylthiazole-5-carbox- amides through a three-component one-pot reaction, which involved potassium methyl cyanimido- dithiocarbonate, 2-halo-N-arylacetamides and alcohols. The easy availability and the broad structural diversity of substrates make the reaction useful for the construction of libraries in drug discovery.展开更多
Objective To investigate the pharmacokinetic effects of baicalin on cerebral ischemia-reperfusion (I/R) after iv administration in rats. Methods The cerebral I/R rats were induced by occluding the bilateral carotid ar...Objective To investigate the pharmacokinetic effects of baicalin on cerebral ischemia-reperfusion (I/R) after iv administration in rats. Methods The cerebral I/R rats were induced by occluding the bilateral carotid arteries of normal rats for 2 h, followed by reperfusion. The resultant animals were immediately iv administrated with baicalin (90 mg/kg), whilst the same dose of baicalin was injected to the normal rats. Plasma samples were collected at different time to construct pharmacokinetic profiles by plotting drug concentration vs time. Quantification of baicalin in rat plasma was achieved using a simple and rapid HPLC method. Results In normal rats, the major parameters of distribution half-life, elimination half-life, area under the plasma concentration-time (AUC), apparent volume of distribution (Vd), and clearance (CL), estimated by an open two-compartmental model, were 0.8868 min, 26.0968 min, 149.6204 mg/min·L, 4.765 L/kg, and 0.5776 L/ kg·min), respectively. However, in I/R rats, the corresponding parameters were 2.084 min, 34.4998 min, 260.0188 μg·min/L, 5.9376 L/kg, and 0.334 L/(kg·min), respectively. Conclusion The cerebral I/R could significantly increase AUC and Vd values, decrease CL values, and prolong the terminal half-life of baicalin. These findings suggest that the injuries of I/R could play an important role in pharmacokinetic process of baicalin.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)Youth Project(No.82204397).
文摘Natural products are the important sources in cardiovascular drug development.In this study,twenty-nine buthutin derivatives were designed,synthesized,and evaluated for their NHE-1 inhibition and protective effects on cardiomyo-cyte injury.The structure of the newly synthesized compounds had been confirmed by 1H-NMR,13C-NMR,and HR-ESI-MS spectra.Among all target compounds at 1μM,compounds 9d,9f,9k,9m,and 9n,with a protection ratio exceeding 30%,exerted stronger protective effects on H9c2 cardiomyocyte than positive control dexrazoxane and buthutin A.Meanwhile,compounds 9k,9m,and 9o showed the significant NHE-1 inhibitory activities on H9c2 cardiomyocyte,all with a dpHi/min value less than 0.23.What is more,compounds 9k,9m,9o and buthutin A all exhibited the specificity on NHE-1 inhibition.Molecular modelling studies suggested the ability of compounds 9m and 9o to establish interactions with three hydrogen bonds to Asp267 and Glu346 of NHE-1,but also the ability with much lower CDOCKER energies than positive control cariporide and buthutin A.The structure-activity relationship(SAR)studies suggested that the presences of amide group,four-carbon linker,and para hydroxyl benzene ring were advantageous pharmacophores for above two pharmacological actions.This research would open new avenues for developing amide-guanidine-based cardioprotective agents.
基金supported by the National Natural Science Foundation of China (No. NSFC. 20872020)the Natural Science Foundation of Guangdong Province (No. 06012298 and No. 8251009001000005)
文摘Objective To prepare artificial antigens and anti-citrinin egg yolk-derived immunoglobulin （IgY） to build an enzyme-linked immunosorbent assay （ELISA） for citrinin （CTN）. Methods CTN was conjugated with bovine serum albumin （BSA）, ovalbumin （OVA） with formaldehyde condensation method to prepare artificial antigens and identified by ultraviolet （UV） spectrometry and Infrared （IR） spectrometry. Artificial antigens for CTN and anti-CTN IgY were purified with polyethylene glycol two-step precipitation method and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. ELISA with IgY was established. Cross-reactivity of IgY with various structural similarities to CTN and possible co-occurrence with CTN in agricultural commodities were studied. Results UV and IR absorption spectra suggested that CTN was correlated with the carrier protein of BSA or OVA. SDS-PAGE patterns showed that the anti-CTN IgY was almost pure with a molecular weight of approximate 100 KD. The indirect competitive ELISA showed that the detection limit of CTN was 10 ng·mL^-1, with a good linearity ranging 20-640 ng·mL^-1. Conclusion Artificial antigens of CTN can be successfully synthesized. The established ELISA can be used to determine CTN- contaminated samples.
基金supported by the National Natural Science Foundation of China(No.30500634) and NSF of Beijing (No.7102112)
文摘A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse isocyanates in the presence of sodium hydride. The easy availability of substrates and tolerance of structural diversity in this reaction make it attractive to be used for construction of libraries in drug discovery process.
基金supported by the National Natural Science Foundation of China(No.81273380)‘‘863’’ Program of China(No.2012AA020302)
文摘A facile and efficient protocol was developed to access 2-alkoxy-4-amino-N-arylthiazole-5-carbox- amides through a three-component one-pot reaction, which involved potassium methyl cyanimido- dithiocarbonate, 2-halo-N-arylacetamides and alcohols. The easy availability and the broad structural diversity of substrates make the reaction useful for the construction of libraries in drug discovery.
基金Guangzhou Science and Technology Program (2010GK-C041)
文摘Objective To investigate the pharmacokinetic effects of baicalin on cerebral ischemia-reperfusion (I/R) after iv administration in rats. Methods The cerebral I/R rats were induced by occluding the bilateral carotid arteries of normal rats for 2 h, followed by reperfusion. The resultant animals were immediately iv administrated with baicalin (90 mg/kg), whilst the same dose of baicalin was injected to the normal rats. Plasma samples were collected at different time to construct pharmacokinetic profiles by plotting drug concentration vs time. Quantification of baicalin in rat plasma was achieved using a simple and rapid HPLC method. Results In normal rats, the major parameters of distribution half-life, elimination half-life, area under the plasma concentration-time (AUC), apparent volume of distribution (Vd), and clearance (CL), estimated by an open two-compartmental model, were 0.8868 min, 26.0968 min, 149.6204 mg/min·L, 4.765 L/kg, and 0.5776 L/ kg·min), respectively. However, in I/R rats, the corresponding parameters were 2.084 min, 34.4998 min, 260.0188 μg·min/L, 5.9376 L/kg, and 0.334 L/(kg·min), respectively. Conclusion The cerebral I/R could significantly increase AUC and Vd values, decrease CL values, and prolong the terminal half-life of baicalin. These findings suggest that the injuries of I/R could play an important role in pharmacokinetic process of baicalin.
