The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal...The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal biotransformation of CCl4 was made. In aerobic nuclear activation mixtures containing NADPH and CCl4, significant decrease in the arachidonic acid content of nuclear lipids was observed (27. 8%, compared to control), the intensity of this decrease was lower than that occurring in the corresponding microsomal incubation mixtures (29.1%). Significant decreases in arachidonic acid content of nuclear and endoplasmic reticulum lipids were also observed in animals at 6 hours of poisoning with the haloalkane. During aerobic nuclear metabolism of CCl4 or CBrCl3, cholesterol oxidation products were detected: a ketocholesterol, an epoxide like structure and 7-ketocholesterol. Nuclear protein carbonyl formation was not promoted during nuclear CCl4 biotransformation. NADPH by itself may lead to protein carbonyl formation during prolonged periods of incubation. CBrCl3 in contrast, led to decreased protein carbonyl formation. No increase in nuclear protein carbonyl formation was observed in CCl4 intoxicated animals during periods of time between 1 to 6 hours after treatment. The results indicate that during nuclear biotransformation of CCl4 or CBrCl3 reactive free radicals, PUFA degradation, reactive aldehydes and cholesterol oxidation products are formed, nearby DNA and regulatory proteins.展开更多
Quantum calculation method has been used to understand and investigate the free radical reactions of propane with hydroxyl radical in vacuum through modem quantum mechanics that is package on hyperchem 8.02 program. O...Quantum calculation method has been used to understand and investigate the free radical reactions of propane with hydroxyl radical in vacuum through modem quantum mechanics that is package on hyperchem 8.02 program. Optimized structures and structural reactivates have been studied through bond stability and angles using DFT calculation based on the basis set 6-31G＊. Energetic properties have been calculated like total energy, Gibbs free energy, entropy, heat of formation, and rate constant for all chemical species that＇s participate in the suggested reaction mechanism. Reaction mechanism and rate determining step had been suggested according to calculation of energy barrier values, and compares between the suggested competitive reactions for each probable reaction step. Suggested structures and the probable transition states have been studied.展开更多
A mathematical mechanism of the n-pentane pyrolysis process based on free radical reaction model was presented.The kinetic parameters of n-pentane pyrolysis are obtained by quantum chemistry and the reaction network i...A mathematical mechanism of the n-pentane pyrolysis process based on free radical reaction model was presented.The kinetic parameters of n-pentane pyrolysis are obtained by quantum chemistry and the reaction network is established. The solution of the stiff ordinary differential equations in the n-pentane pyrolysis model is completed by semi implicit Eular algorithm. Then the pyrolysis mechanism based on free radical reaction model is built,and the computational efficiency increases 10 times by algorithm optimization. The validity of this model and its solution method is confirmed by the experimental results of n-pentane pyrolysis.展开更多
The frequent detection of pharmaceutical compounds in the environment has led to a growing awareness,which may pose a major threat to the aquatic environment.In this study,photodegradation(direct and indirect photolys...The frequent detection of pharmaceutical compounds in the environment has led to a growing awareness,which may pose a major threat to the aquatic environment.In this study,photodegradation(direct and indirect photolysis)of two different dissociation states of fluoxetine(FLU)was investigated in water,mainly including the determination of photolytic transition states and products,and the mechanisms of indirect photodegradation with·OH,CO_(3)^(*-)and NO_(3)^(*).The main direct photolysis pathways are defluorination and C–C bond cleavage.In addition,the indirect photodegradation of FLU in water is mainly through the reactions with·OH and NO_(3)^(*),and the photodegradation reaction with CO_(3)^(*-)is relatively difficult to occur in the water environment.Our results provide a theoretical basis for understanding the phototransformation process of FLU in the water environment and assessing its potential risk.展开更多
We reveal here a visible-light promoted phosphorylation of 2-isocyanoaryl thioethers for the first time with concomita nt C(sp3)-S bond cleavage and imidoyl C-S fo rmation.Additionally,this method features the use of ...We reveal here a visible-light promoted phosphorylation of 2-isocyanoaryl thioethers for the first time with concomita nt C(sp3)-S bond cleavage and imidoyl C-S fo rmation.Additionally,this method features the use of 3 mol%organic dye Rose Bengal as the photocatalyst without external transition-metal or peroxide oxidants,and provides a novel and environmentally friendly approach for the preparation of a variety of 2-phosphoryl benzothiazoles in moderate to good yields.展开更多
The reaction of naphthalene with oxalyl chloride in the presence of anhydrous AlCl3 was investigated. The homolog of dinaphthyl methanone can be obtained mainly from this reaction. Naphthalene conversion does not have...The reaction of naphthalene with oxalyl chloride in the presence of anhydrous AlCl3 was investigated. The homolog of dinaphthyl methanone can be obtained mainly from this reaction. Naphthalene conversion does not have evident correlation with the amount of AlCl3. The results show that the reaction proceeds via carbon cation electrophilic substitution reaction-free radical substitution reaction pathway.展开更多
A facile and efficient synthesis of N-sulfonyl-N,N-disubstituted amidines has been achieved via a CuI-catalyzed three-component free-radical coupling reaction of tertiary amines and arenesulfonyl azides with terminal ...A facile and efficient synthesis of N-sulfonyl-N,N-disubstituted amidines has been achieved via a CuI-catalyzed three-component free-radical coupling reaction of tertiary amines and arenesulfonyl azides with terminal alkynes in the presence of azodiisobutyronitrile(AIBN).The reaction mechanism of this reaction has also been studied.展开更多
Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of bindi...Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of binding and fusionwith the oocyte. During capacitation various biochemical and biophysical changes occur in the spermatozoa and thespermatozoal membranes. Ions and ion channels also play important roles in governing the process of capacitation bychanging the fluxes of different ions which in turn controls various characteristics of capacitated spermatozoa. Alongwith the mobilization of ions the generation of free radicals and efflux of cholesterol also plays an important role in thecapacitation state of the spermatozoa. The generation of free radical and efflux of cholesterol change the mechano-dynamic properties of the membrane by oxidation of the polyunsaturated lipids and by generating the cholesterol freepatches. The process of capacitation renders the spermatozoa responsive to the inducers of the acrosome reaction. Theglycoprotein zona pellucida 3 (ZP3) of the egg coat zona pellucida is the potent physiological stimulator of the acro-some reaction; progesterone, a major compoent of the follicular fluid, is also an induce of the acrosome reaction.The inducers of the acrosome reaction cause the activation of the various ion-channels leading to high influxes of calci-um, sodium and bicarbonate. The efflux of cholesterol during the process of capacitation alters the permeablity of themembrane to the ions and generate areas which are prone to fusion and vesculation process during the acrosome reac-tion. Ths review focuses mainly on effects of the ion and ion-channels, free radicals, and membrane fluidity changesduring the process of capacitation and acrosome reaction. (Asian J Androl 1999 Sep; 1: 95-107)展开更多
文摘The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal biotransformation of CCl4 was made. In aerobic nuclear activation mixtures containing NADPH and CCl4, significant decrease in the arachidonic acid content of nuclear lipids was observed (27. 8%, compared to control), the intensity of this decrease was lower than that occurring in the corresponding microsomal incubation mixtures (29.1%). Significant decreases in arachidonic acid content of nuclear and endoplasmic reticulum lipids were also observed in animals at 6 hours of poisoning with the haloalkane. During aerobic nuclear metabolism of CCl4 or CBrCl3, cholesterol oxidation products were detected: a ketocholesterol, an epoxide like structure and 7-ketocholesterol. Nuclear protein carbonyl formation was not promoted during nuclear CCl4 biotransformation. NADPH by itself may lead to protein carbonyl formation during prolonged periods of incubation. CBrCl3 in contrast, led to decreased protein carbonyl formation. No increase in nuclear protein carbonyl formation was observed in CCl4 intoxicated animals during periods of time between 1 to 6 hours after treatment. The results indicate that during nuclear biotransformation of CCl4 or CBrCl3 reactive free radicals, PUFA degradation, reactive aldehydes and cholesterol oxidation products are formed, nearby DNA and regulatory proteins.
文摘Quantum calculation method has been used to understand and investigate the free radical reactions of propane with hydroxyl radical in vacuum through modem quantum mechanics that is package on hyperchem 8.02 program. Optimized structures and structural reactivates have been studied through bond stability and angles using DFT calculation based on the basis set 6-31G＊. Energetic properties have been calculated like total energy, Gibbs free energy, entropy, heat of formation, and rate constant for all chemical species that＇s participate in the suggested reaction mechanism. Reaction mechanism and rate determining step had been suggested according to calculation of energy barrier values, and compares between the suggested competitive reactions for each probable reaction step. Suggested structures and the probable transition states have been studied.
文摘A mathematical mechanism of the n-pentane pyrolysis process based on free radical reaction model was presented.The kinetic parameters of n-pentane pyrolysis are obtained by quantum chemistry and the reaction network is established. The solution of the stiff ordinary differential equations in the n-pentane pyrolysis model is completed by semi implicit Eular algorithm. Then the pyrolysis mechanism based on free radical reaction model is built,and the computational efficiency increases 10 times by algorithm optimization. The validity of this model and its solution method is confirmed by the experimental results of n-pentane pyrolysis.
基金supported by the National Natural Science Foundation of China(No.41601519)。
文摘The frequent detection of pharmaceutical compounds in the environment has led to a growing awareness,which may pose a major threat to the aquatic environment.In this study,photodegradation(direct and indirect photolysis)of two different dissociation states of fluoxetine(FLU)was investigated in water,mainly including the determination of photolytic transition states and products,and the mechanisms of indirect photodegradation with·OH,CO_(3)^(*-)and NO_(3)^(*).The main direct photolysis pathways are defluorination and C–C bond cleavage.In addition,the indirect photodegradation of FLU in water is mainly through the reactions with·OH and NO_(3)^(*),and the photodegradation reaction with CO_(3)^(*-)is relatively difficult to occur in the water environment.Our results provide a theoretical basis for understanding the phototransformation process of FLU in the water environment and assessing its potential risk.
基金financial support from the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.19KJB150020)Basic Research Project(Natural Science Foundation for Young Scholars)of Jiangsu Province,China(No.BK20170489,BK20180916)+1 种基金High Level Introduction of Talent Research Start-up Foundation of YZU(No.137011457)China Postdoctoral Science Foundation(No.2019T120471)。
文摘We reveal here a visible-light promoted phosphorylation of 2-isocyanoaryl thioethers for the first time with concomita nt C(sp3)-S bond cleavage and imidoyl C-S fo rmation.Additionally,this method features the use of 3 mol%organic dye Rose Bengal as the photocatalyst without external transition-metal or peroxide oxidants,and provides a novel and environmentally friendly approach for the preparation of a variety of 2-phosphoryl benzothiazoles in moderate to good yields.
基金Supported by the National Nature Science Foundation of China ( 2 96 76 0 45 )
文摘The reaction of naphthalene with oxalyl chloride in the presence of anhydrous AlCl3 was investigated. The homolog of dinaphthyl methanone can be obtained mainly from this reaction. Naphthalene conversion does not have evident correlation with the amount of AlCl3. The results show that the reaction proceeds via carbon cation electrophilic substitution reaction-free radical substitution reaction pathway.
基金National Natural Science Foundation of China (20872001)the Anhui Education Department (TD200707 & KJ2008A064)+1 种基金the Program for the NCET (NCET-10-0004)the Research Culture Funds of Anhui Normal University (2010rcpy041) for their financial support
文摘A facile and efficient synthesis of N-sulfonyl-N,N-disubstituted amidines has been achieved via a CuI-catalyzed three-component free-radical coupling reaction of tertiary amines and arenesulfonyl azides with terminal alkynes in the presence of azodiisobutyronitrile(AIBN).The reaction mechanism of this reaction has also been studied.
文摘Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of binding and fusionwith the oocyte. During capacitation various biochemical and biophysical changes occur in the spermatozoa and thespermatozoal membranes. Ions and ion channels also play important roles in governing the process of capacitation bychanging the fluxes of different ions which in turn controls various characteristics of capacitated spermatozoa. Alongwith the mobilization of ions the generation of free radicals and efflux of cholesterol also plays an important role in thecapacitation state of the spermatozoa. The generation of free radical and efflux of cholesterol change the mechano-dynamic properties of the membrane by oxidation of the polyunsaturated lipids and by generating the cholesterol freepatches. The process of capacitation renders the spermatozoa responsive to the inducers of the acrosome reaction. Theglycoprotein zona pellucida 3 (ZP3) of the egg coat zona pellucida is the potent physiological stimulator of the acro-some reaction; progesterone, a major compoent of the follicular fluid, is also an induce of the acrosome reaction.The inducers of the acrosome reaction cause the activation of the various ion-channels leading to high influxes of calci-um, sodium and bicarbonate. The efflux of cholesterol during the process of capacitation alters the permeablity of themembrane to the ions and generate areas which are prone to fusion and vesculation process during the acrosome reac-tion. Ths review focuses mainly on effects of the ion and ion-channels, free radicals, and membrane fluidity changesduring the process of capacitation and acrosome reaction. (Asian J Androl 1999 Sep; 1: 95-107)
