2-Substituted-2,3-dihydro-4(1H)-quinazolinones were obtained in high yields by condensation of anthranilamide with aryl, alkyl or heteroaryl aldehydes or ketones in the refluxing 2,2,2-trifluoroethanol without any cat...2-Substituted-2,3-dihydro-4(1H)-quinazolinones were obtained in high yields by condensation of anthranilamide with aryl, alkyl or heteroaryl aldehydes or ketones in the refluxing 2,2,2-trifluoroethanol without any catalyst.展开更多
Trifluoroethanol has often been used in protein folding studies. The changes in activity and unfolding of arginine kinase from shrimp Feneropenaeus chinensis muscle during denaturation in different concentrations o...Trifluoroethanol has often been used in protein folding studies. The changes in activity and unfolding of arginine kinase from shrimp Feneropenaeus chinensis muscle during denaturation in different concentrations of trifuoroethanol were investigated using far ultraviolet circular dichroism and fluorescence emission spectra. Arginine kinase was inactivated in trifluoroethanol solutions. The tertiary and secondary structures of arginine kinase were also destroyed in the trifluoroethanol solutions. The unfolding and inactivation courses were measured and compared. Inactivation occurred prior to unfolding, which suggests that the arginine kinase active site is more easily damaged by the denaturant than the enzyme as a whole. The result also indicates that the arginine kinase active site is situated in a limited and flexible region of the enzyme molecule.展开更多
Alkaline phosphatase is a stable enzyme which is strongly resistant to urea, guanidine hydrochloride, acid pH, and heat. But there have been few studies on the effect of organic cosolvents on the activity and struct...Alkaline phosphatase is a stable enzyme which is strongly resistant to urea, guanidine hydrochloride, acid pH, and heat. But there have been few studies on the effect of organic cosolvents on the activity and structure of alkaline phosphatase. The activity of calf intestinal alkaline phosphatase (CIAP) is markedly increased when incubated in solutions with elevated trifluoroethanol (TFE) concentrations. The activation is a time dependent course. There is a very fast phase in the activation kinetics in the mixing dead time (30 s) using convential methods. Further activation after the very fast phase follows biphasic kinetics. The structural basis of the activation has been monitored by intrinsic fluorescence and far ultraviolet circular dichroism. TFE (060%) did not lead to any significant change in the intrinsic fluorescence emission maximum, indicating no significant change in the tertiary structure of CIAP. But TFE did significantly change the secondary structure of CIAP, especially increasing α helix content. We conclude that the activation of CIAP is due to its secondary structural change. The time for the secondary structure change induced by TFE preceds that of the activity increase. These results suggest that a rapid conformational change of CIAP induced by TFE results in the enhancement of CIAP activity, followed by further increase of this activity because of the further slightly slower rearrangements of the activated conformation. It is concluded that the higher catalytic activity of CIAP can be attained with various secondary structures.展开更多
A promoter-free Friedel-Crafts trifluoromethylthiolation of electron-rich arenes and heteroarenes with N-trifluoromethylthiosaccharin 5 using 2,2,2-trifluoroethanol(TFE) as the solvent was described.The reactions were...A promoter-free Friedel-Crafts trifluoromethylthiolation of electron-rich arenes and heteroarenes with N-trifluoromethylthiosaccharin 5 using 2,2,2-trifluoroethanol(TFE) as the solvent was described.The reactions were conducted at 40℃and a variety of common functional groups were compatible.展开更多
A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4（1H）-quinazolinones was developed by condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaro...A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4（1H）-quinazolinones was developed by condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaromatic aldehydes in the refluxing 2,2,2- trifluoroethanol or hexafluoroisopropanol using p-toluenesulfonic acid as catalyst.展开更多
Anesthetics evoke a stress-response, upregulating heat shock genes. This neuroprotective response to proteotoxic stress represents preconditioning, a process by which neuronal tissue, previously exposed to anesthetics...Anesthetics evoke a stress-response, upregulating heat shock genes. This neuroprotective response to proteotoxic stress represents preconditioning, a process by which neuronal tissue, previously exposed to anesthetics, is protected against future insult. It presumes a sub-lethal injury, affecting protein unfolding. Our hypothesis is: preconditioning evokes molecular events that result in downstream changes that offer a selective advantage in terms of neuronal function. We focused on the neurobehavioral aspects which we neurophenotyped. Larval zebrafish were exposed to trifluoroethanol (TFE), an anesthetic mimetic, and tested for both individual and group behavioral markers of neuronal function. In bright/dark tests, we observed that TFE-exposed larvae spent more time in the dark area (typically an adult-like response) than control larvae. The response of TFE larvae to noise startle was directly opposite to that of controls. TFE larvae swam towards the source of the startle (into the bright zone), whereas control larvae swam away from the source of the startle (into the dark), typical of fear-response. The larvae also exhibited several differences in social behaviors, including synchronized schooling and shoaling behaviors. The TFE-group showed a greater number of synchronized events versus controls. The TFE-group also exhibited more shoaling events compared with controls. While the long-term effects have yet to be determined, these results shed light on the mechanism of anesthetic preconditioning. These complex zebrafish behaviors normally develop with age and therefore represent, in the TFE-exposed group, a pattern of accelerated maturation of neuronal function, which is the neurophenotype attributed to preconditioning.展开更多
A green and convenient approach for the synthesis of a series of 5,5＇-（arylmethylene）bis（4-hydroxythiazole-2（3H）-one） by the reaction of aryl aldehydes,monochloroacetic acid and ammonium thiocyanate in water/tr...A green and convenient approach for the synthesis of a series of 5,5＇-（arylmethylene）bis（4-hydroxythiazole-2（3H）-one） by the reaction of aryl aldehydes,monochloroacetic acid and ammonium thiocyanate in water/trifluoroethanol（TFE）（1：1） under ultrasound irradiation at room temperature is described.This method provides several advantages such as environmental friendliness,shorter time,excellent yields,and simple work-up procedure.展开更多
文摘2-Substituted-2,3-dihydro-4(1H)-quinazolinones were obtained in high yields by condensation of anthranilamide with aryl, alkyl or heteroaryl aldehydes or ketones in the refluxing 2,2,2-trifluoroethanol without any catalyst.
基金Supported by the National Key Basic Research Specific Foundation of China(No.G19990 75 6 0 7)
文摘Trifluoroethanol has often been used in protein folding studies. The changes in activity and unfolding of arginine kinase from shrimp Feneropenaeus chinensis muscle during denaturation in different concentrations of trifuoroethanol were investigated using far ultraviolet circular dichroism and fluorescence emission spectra. Arginine kinase was inactivated in trifluoroethanol solutions. The tertiary and secondary structures of arginine kinase were also destroyed in the trifluoroethanol solutions. The unfolding and inactivation courses were measured and compared. Inactivation occurred prior to unfolding, which suggests that the arginine kinase active site is more easily damaged by the denaturant than the enzyme as a whole. The result also indicates that the arginine kinase active site is situated in a limited and flexible region of the enzyme molecule.
基金Supported by the National Key Basic Research Specific Foundation of China( No.G19990 75 60 7)
文摘Alkaline phosphatase is a stable enzyme which is strongly resistant to urea, guanidine hydrochloride, acid pH, and heat. But there have been few studies on the effect of organic cosolvents on the activity and structure of alkaline phosphatase. The activity of calf intestinal alkaline phosphatase (CIAP) is markedly increased when incubated in solutions with elevated trifluoroethanol (TFE) concentrations. The activation is a time dependent course. There is a very fast phase in the activation kinetics in the mixing dead time (30 s) using convential methods. Further activation after the very fast phase follows biphasic kinetics. The structural basis of the activation has been monitored by intrinsic fluorescence and far ultraviolet circular dichroism. TFE (060%) did not lead to any significant change in the intrinsic fluorescence emission maximum, indicating no significant change in the tertiary structure of CIAP. But TFE did significantly change the secondary structure of CIAP, especially increasing α helix content. We conclude that the activation of CIAP is due to its secondary structural change. The time for the secondary structure change induced by TFE preceds that of the activity increase. These results suggest that a rapid conformational change of CIAP induced by TFE results in the enhancement of CIAP activity, followed by further increase of this activity because of the further slightly slower rearrangements of the activated conformation. It is concluded that the higher catalytic activity of CIAP can be attained with various secondary structures.
基金the financial support from the National Natural Science Foundation of China (Nos.21625206, 21632009,21572258,21421002)the Natural Science Foundation of Shanghai (No.17ZR1447100)the Science and Technology Commission of Shanghai Municipality (No.14DZ2261000)
文摘A promoter-free Friedel-Crafts trifluoromethylthiolation of electron-rich arenes and heteroarenes with N-trifluoromethylthiosaccharin 5 using 2,2,2-trifluoroethanol(TFE) as the solvent was described.The reactions were conducted at 40℃and a variety of common functional groups were compatible.
基金We are grateful to the National Natural Science Foundation of China(No.30672540)the Natural Science Foundation of Beijing(No.7072048)for financial support.
文摘A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4（1H）-quinazolinones was developed by condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaromatic aldehydes in the refluxing 2,2,2- trifluoroethanol or hexafluoroisopropanol using p-toluenesulfonic acid as catalyst.
文摘Anesthetics evoke a stress-response, upregulating heat shock genes. This neuroprotective response to proteotoxic stress represents preconditioning, a process by which neuronal tissue, previously exposed to anesthetics, is protected against future insult. It presumes a sub-lethal injury, affecting protein unfolding. Our hypothesis is: preconditioning evokes molecular events that result in downstream changes that offer a selective advantage in terms of neuronal function. We focused on the neurobehavioral aspects which we neurophenotyped. Larval zebrafish were exposed to trifluoroethanol (TFE), an anesthetic mimetic, and tested for both individual and group behavioral markers of neuronal function. In bright/dark tests, we observed that TFE-exposed larvae spent more time in the dark area (typically an adult-like response) than control larvae. The response of TFE larvae to noise startle was directly opposite to that of controls. TFE larvae swam towards the source of the startle (into the bright zone), whereas control larvae swam away from the source of the startle (into the dark), typical of fear-response. The larvae also exhibited several differences in social behaviors, including synchronized schooling and shoaling behaviors. The TFE-group showed a greater number of synchronized events versus controls. The TFE-group also exhibited more shoaling events compared with controls. While the long-term effects have yet to be determined, these results shed light on the mechanism of anesthetic preconditioning. These complex zebrafish behaviors normally develop with age and therefore represent, in the TFE-exposed group, a pattern of accelerated maturation of neuronal function, which is the neurophenotype attributed to preconditioning.
文摘A green and convenient approach for the synthesis of a series of 5,5＇-（arylmethylene）bis（4-hydroxythiazole-2（3H）-one） by the reaction of aryl aldehydes,monochloroacetic acid and ammonium thiocyanate in water/trifluoroethanol（TFE）（1：1） under ultrasound irradiation at room temperature is described.This method provides several advantages such as environmental friendliness,shorter time,excellent yields,and simple work-up procedure.
