A series of 1,2-cyclic monoacyl-rac-glycerothiophosphates of cantharidin and its analogues were synthesized in a one-pot procedure in overall yields of 44 similar to 55.5% by means of hexaethylphosphorus triamide as p...A series of 1,2-cyclic monoacyl-rac-glycerothiophosphates of cantharidin and its analogues were synthesized in a one-pot procedure in overall yields of 44 similar to 55.5% by means of hexaethylphosphorus triamide as phosphorylating reagent.展开更多
UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with ...UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.展开更多
Cyclic ADP-ribose (cADPR) is a universal Ca2+ mobilizing second messenger in many different cell types and organisms. cADPR activates Ca2+ release from endo/sarcoplasmic reticulum via ryanodine receptors. In addition,...Cyclic ADP-ribose (cADPR) is a universal Ca2+ mobilizing second messenger in many different cell types and organisms. cADPR activates Ca2+ release from endo/sarcoplasmic reticulum via ryanodine receptors. In addition, Ca2+ entry secondary to Ca2+ depletion is at least one of the mechanisms in which cADPR triggers Ca2+ inflow, too. Analogues of cADPR have been prepared by chemical and chemo-enzymatic routes. Most of the analogues were analyzed for biological activity in intact or permeabilized Jurkat T cells (a human T-lymphoma cell line). As a systematic approach, analogues were grouped according to alterations in the base, the northern ribose, the southern ribose, the pyrophosphate backbone, or in complex modifications, comprising more than one part of the molecule. Biological activity of the analogues is reviewed, with special emphasis on Jurkat T cells.展开更多
Background： The CD38/cyclic ADP-ribose （cADPR） pathway plays a role in various central nervous system diseases and in morphine tolerance, but its role in local anesthetic intoxication is unknown. The aim of this st...Background： The CD38/cyclic ADP-ribose （cADPR） pathway plays a role in various central nervous system diseases and in morphine tolerance, but its role in local anesthetic intoxication is unknown. The aim of this study was to determine the role of the CD38/cADPR pathway in ropivacaine-induced convulsion. Methods： Forty male Sprague-Dawley rats were randomly divided into five groups （n = 8 per group）： sham group, ropivacaine group, ropivacaine＋8-Br-cADPR （5 nmol） group, ropivacaine＋8-Br-cADPR （10 nmol） group, and ropivacaine＋8-Br-cADPR （20 nmol） group （no rats died）. Rats were intracerebroventricularly injected with normal saline or 8-Br-cADPR 30 min before receiving an intraperitoneal injection of ropivacaine. Electroencephalography and convulsion behavior scores were recorded. The hippocampus was harvested from each group and subjected to nicotinamide adenine dinucleotide and cADPR assays, Western blotting analysis, and malondialdehyde （MDA） and superoxide dismutase （SOD） assays. Results： Intraperitoneal injection of ropivacaine （33.8 mg/kg） induced convulsions in rats. CD38 and cADPR levels increased significantly following ropivacaine-induced convulsion （P = 0.031 and 0.020, respectively, compared with the sham group）. Intraventricular injection of 8-Br-cADPR （5, 10, and 20 nmol） significantly prolonged convulsion latency （P = 0.037, 0.034, and 0.000, respectively）, reduced convulsion duration （P = 0.005, 0.005, and 0.005, respectively）, and reduced convulsion behavior scores （P = 0.015, 0.015, and 0.000, respectively）. Intraventricular injection of 8-Br-cADPR （10 nmol） also increased the B-cell lymphoma-2 （Bcl-2）/Bcl-2-associated X protein ratio （P = 0.044） and reduced cleaved Caspase 3/Caspase 3 ratio, inducible nitric oxide synthase, MDAand SOD levels （P = 0.014, 0.044, 0.001, and 0.010, respectively） compared with the ropivacaine group. Conclusions： The CD38/cADPR pathway is activated in ropivacaine-induced convulsion. Inhibiting this pathway alleviates ropivacaine-induced convulsion and protects the brain from apoptosis and oxidative stress.展开更多
1,4-anhydro-2-trifiyl-3,5-O-benzenylidene-L-xylitol (5) was constructed in six steps from protected D-xylose. Substitution of 5 with protected 8-bromoinosine 6 gave the key intermediate 5 ' -O-TBS-2 ' ,3 '...1,4-anhydro-2-trifiyl-3,5-O-benzenylidene-L-xylitol (5) was constructed in six steps from protected D-xylose. Substitution of 5 with protected 8-bromoinosine 6 gave the key intermediate 5 ' -O-TBS-2 ' ,3 ' -di-O-acctyl-N-1-(2 ' -deoxy-1 ' ,4 ' -anhydro-3 ' ,5 ' -O-benzenylidene (14). Selective removal of 5 ' -O-TBS-group gave the corresponding though phosphorylation which was characterized by X-ray crystallographical analysis.展开更多
An NAD analogue, N-(2-thiol-ethyl)-nicotinamide (TENA), was synthesized. TENA was used to modify the Au electrode through self-assembled monolayer.The cyclic voltammetry study of the electrode was carried out. The int...An NAD analogue, N-(2-thiol-ethyl)-nicotinamide (TENA), was synthesized. TENA was used to modify the Au electrode through self-assembled monolayer.The cyclic voltammetry study of the electrode was carried out. The interference of dimerization of the NAD analogues reported in the literature was successfully avoided. The results support a mechanism of an electron transfer followed by chemical reaction during part of the redox process of TENA. Some useful reaction parameters were obtained.展开更多
The development of effective and low-energy-consumption catalysts for CO_(2)conversion into high-value-added products by constructing versatile active sites on the surface of heterogeneous compounds is an ur-gent and ...The development of effective and low-energy-consumption catalysts for CO_(2)conversion into high-value-added products by constructing versatile active sites on the surface of heterogeneous compounds is an ur-gent and challenging task.In this study,a stable and well-defined heterogeneous cobalt hexacyanocobal-tate(Co_(3)[Co(CN)_(6)]_(2)),typical cobalt Prussian blue analogue(CoCo-PBA)modified with tetrabutylammo-nium bromide(TBAB),is proven to be the superior catalyst for CO_(2)and epoxide coupling to produce cyclic carbonates with>99%yield under mild reaction conditions(1.0 MPa,65℃).Based on a series of characterizations,it is revealed that the CoCo-PBA structure can maintain relatively high thermal and chemical stability.Recycling experiments exhibited that the CoCo-PBA system could retain 98%of the original activity after six reaction rounds.The CoCo-PBA/TBAB catalytic system was also highly active for coupling CO_(2)with other industrial-grade epoxides.These results show the Co Co-PBA catalytic system potential flexibility and the generality of the catalyst preparation strategy.展开更多
文摘A series of 1,2-cyclic monoacyl-rac-glycerothiophosphates of cantharidin and its analogues were synthesized in a one-pot procedure in overall yields of 44 similar to 55.5% by means of hexaethylphosphorus triamide as phosphorylating reagent.
基金thanks to the Austrian grant(ASO)SK-06/07-14/2007the Faculty of Mediccine Research Fund(University of Pécs)AOK-KA-213/20.
文摘UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.
基金supported over the past couple of years by the Deutsche Forschungsge-meinschaftthe Gemeinnützige Hertie-Stiftung+1 种基金the Well-come Trustthe Deutsche Akademische Austauschdienst
文摘Cyclic ADP-ribose (cADPR) is a universal Ca2+ mobilizing second messenger in many different cell types and organisms. cADPR activates Ca2+ release from endo/sarcoplasmic reticulum via ryanodine receptors. In addition, Ca2+ entry secondary to Ca2+ depletion is at least one of the mechanisms in which cADPR triggers Ca2+ inflow, too. Analogues of cADPR have been prepared by chemical and chemo-enzymatic routes. Most of the analogues were analyzed for biological activity in intact or permeabilized Jurkat T cells (a human T-lymphoma cell line). As a systematic approach, analogues were grouped according to alterations in the base, the northern ribose, the southern ribose, the pyrophosphate backbone, or in complex modifications, comprising more than one part of the molecule. Biological activity of the analogues is reviewed, with special emphasis on Jurkat T cells.
文摘Background： The CD38/cyclic ADP-ribose （cADPR） pathway plays a role in various central nervous system diseases and in morphine tolerance, but its role in local anesthetic intoxication is unknown. The aim of this study was to determine the role of the CD38/cADPR pathway in ropivacaine-induced convulsion. Methods： Forty male Sprague-Dawley rats were randomly divided into five groups （n = 8 per group）： sham group, ropivacaine group, ropivacaine＋8-Br-cADPR （5 nmol） group, ropivacaine＋8-Br-cADPR （10 nmol） group, and ropivacaine＋8-Br-cADPR （20 nmol） group （no rats died）. Rats were intracerebroventricularly injected with normal saline or 8-Br-cADPR 30 min before receiving an intraperitoneal injection of ropivacaine. Electroencephalography and convulsion behavior scores were recorded. The hippocampus was harvested from each group and subjected to nicotinamide adenine dinucleotide and cADPR assays, Western blotting analysis, and malondialdehyde （MDA） and superoxide dismutase （SOD） assays. Results： Intraperitoneal injection of ropivacaine （33.8 mg/kg） induced convulsions in rats. CD38 and cADPR levels increased significantly following ropivacaine-induced convulsion （P = 0.031 and 0.020, respectively, compared with the sham group）. Intraventricular injection of 8-Br-cADPR （5, 10, and 20 nmol） significantly prolonged convulsion latency （P = 0.037, 0.034, and 0.000, respectively）, reduced convulsion duration （P = 0.005, 0.005, and 0.005, respectively）, and reduced convulsion behavior scores （P = 0.015, 0.015, and 0.000, respectively）. Intraventricular injection of 8-Br-cADPR （10 nmol） also increased the B-cell lymphoma-2 （Bcl-2）/Bcl-2-associated X protein ratio （P = 0.044） and reduced cleaved Caspase 3/Caspase 3 ratio, inducible nitric oxide synthase, MDAand SOD levels （P = 0.014, 0.044, 0.001, and 0.010, respectively） compared with the ropivacaine group. Conclusions： The CD38/cADPR pathway is activated in ropivacaine-induced convulsion. Inhibiting this pathway alleviates ropivacaine-induced convulsion and protects the brain from apoptosis and oxidative stress.
文摘1,4-anhydro-2-trifiyl-3,5-O-benzenylidene-L-xylitol (5) was constructed in six steps from protected D-xylose. Substitution of 5 with protected 8-bromoinosine 6 gave the key intermediate 5 ' -O-TBS-2 ' ,3 ' -di-O-acctyl-N-1-(2 ' -deoxy-1 ' ,4 ' -anhydro-3 ' ,5 ' -O-benzenylidene (14). Selective removal of 5 ' -O-TBS-group gave the corresponding though phosphorylation which was characterized by X-ray crystallographical analysis.
文摘An NAD analogue, N-(2-thiol-ethyl)-nicotinamide (TENA), was synthesized. TENA was used to modify the Au electrode through self-assembled monolayer.The cyclic voltammetry study of the electrode was carried out. The interference of dimerization of the NAD analogues reported in the literature was successfully avoided. The results support a mechanism of an electron transfer followed by chemical reaction during part of the redox process of TENA. Some useful reaction parameters were obtained.
基金financial support of the National Natural Science Foundation of China (Nos.21774108 and 51973190)。
文摘The development of effective and low-energy-consumption catalysts for CO_(2)conversion into high-value-added products by constructing versatile active sites on the surface of heterogeneous compounds is an ur-gent and challenging task.In this study,a stable and well-defined heterogeneous cobalt hexacyanocobal-tate(Co_(3)[Co(CN)_(6)]_(2)),typical cobalt Prussian blue analogue(CoCo-PBA)modified with tetrabutylammo-nium bromide(TBAB),is proven to be the superior catalyst for CO_(2)and epoxide coupling to produce cyclic carbonates with>99%yield under mild reaction conditions(1.0 MPa,65℃).Based on a series of characterizations,it is revealed that the CoCo-PBA structure can maintain relatively high thermal and chemical stability.Recycling experiments exhibited that the CoCo-PBA system could retain 98%of the original activity after six reaction rounds.The CoCo-PBA/TBAB catalytic system was also highly active for coupling CO_(2)with other industrial-grade epoxides.These results show the Co Co-PBA catalytic system potential flexibility and the generality of the catalyst preparation strategy.
