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
A series of（Z）-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis（...A series of（Z）-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis（trichloromethyl） carbonate（BTC, triphosgene） and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.展开更多
Thifensulfuron was synthesized in two steps by reacting bis(trichloromethyl)carbonate(BTC) as a phosgene substitute with 2 methoxycarbonyl 3 aminosulfonylthiophene(AST) to give an intermediate sulfonylisocynate, which...Thifensulfuron was synthesized in two steps by reacting bis(trichloromethyl)carbonate(BTC) as a phosgene substitute with 2 methoxycarbonyl 3 aminosulfonylthiophene(AST) to give an intermediate sulfonylisocynate, which reacted with 2 amino 4 methoxy 6 methyl 1,3,5 triazine to give thifensulfuron. The optimum reaction conditions were n (AST)∶ n (BTC)=1∶0 56, reaction temperature 120～130 ℃ and reaction time (11±0 5) h. The purity of thifensulfuron obtained was 96 5%(HPLC) in overall yield 93%.展开更多
基金the National Basic Research Program of China 973 Program(No.2003CB114400)the National Natural Science Foundation of China(No.20476098)for financial support.(No.20676123)
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.
基金the National Natural Science Foundation of China(Nos.20806073 and 20876147)the National Key Technology Research and Development Program(No.2007BAI34B06) for financial support
文摘A series of（Z）-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis（trichloromethyl） carbonate（BTC, triphosgene） and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.
文摘Thifensulfuron was synthesized in two steps by reacting bis(trichloromethyl)carbonate(BTC) as a phosgene substitute with 2 methoxycarbonyl 3 aminosulfonylthiophene(AST) to give an intermediate sulfonylisocynate, which reacted with 2 amino 4 methoxy 6 methyl 1,3,5 triazine to give thifensulfuron. The optimum reaction conditions were n (AST)∶ n (BTC)=1∶0 56, reaction temperature 120～130 ℃ and reaction time (11±0 5) h. The purity of thifensulfuron obtained was 96 5%(HPLC) in overall yield 93%.
