Manganese-catalyzed C—C bond cleavage of cyclobutanols has attracted great attention due to the high abundance and cheap and eco-friendly behaviour.A manganese-catalyzed ring-opening C—C bond fluorination of cyclobu...Manganese-catalyzed C—C bond cleavage of cyclobutanols has attracted great attention due to the high abundance and cheap and eco-friendly behaviour.A manganese-catalyzed ring-opening C—C bond fluorination of cyclobutanols is reported.Under mild conditions,the reaction provides a straightforward access to γ-fluorinated ketones using 10 mol% Mn(OAc)_(2) as catalyst and electrophilic fluorination reagent,which was generated in situ from HF·Et 3N and PhIO,as fluorine source.The reaction has an excellent functional-group tolerance and displays a broad substrate scope,affording the corresponding products in 50%~76%yields.展开更多
For preparing fluorinated quinolone antibiotic medicine locally used in stomatology, simultaneous determination of norfloxacin, ciprofloxacin, and enoxacin was carried out by multiphase ion chromatography with fluores...For preparing fluorinated quinolone antibiotic medicine locally used in stomatology, simultaneous determination of norfloxacin, ciprofloxacin, and enoxacin was carried out by multiphase ion chromatography with fluorescence detection. Quinolone antibiotics were separated by Dionex OmniPac PAX-500 column with an eluent of 15 mmol/L H2SO4 and 35% methanol （v/v） at a flow-rate of 1.0 ml/min and detected with fluorescence with excitation and emission wave lengths of 347 ran and 420 ran respectively. The detection limits （S/N=3） of norfloxacin, ciprofloxacin and enoxacin were 50, 105 and 80 ng/ml respectively. The relative standard deviations of retention time, peak area and peak height were less than 1.1% and good linear relationship resulted. The developed method was applied to pharmaceutical formulations and biological fluids.展开更多
TiO2hollow microspheres(TiO2‐HMSs)have attracted much attention because of their high photoreactivity,low density,and good permeability.However,anatase TiO2‐HMSs have poor thermal stability.In this study,surface‐fl...TiO2hollow microspheres(TiO2‐HMSs)have attracted much attention because of their high photoreactivity,low density,and good permeability.However,anatase TiO2‐HMSs have poor thermal stability.In this study,surface‐fluorinated TiO2‐HMSs were assembled from hollow nanoparticles by the hydrothermal reaction of the mixed Ti(SO4)2–NH4HF–H2O2solution at180°C.The effect of the calcination temperature on the structure and photoreactivity of the TiO2‐HMSs was systematically investigated,which was evaluated by photocatalytic oxidation of acetone in air under ultraviolet irradiation.We found that after calcination at300°C,the photoreactivity of the TiO2‐HMSs decreases from1.39×10?3min?1(TiO2‐HMS precursor)to0.82×10?3min?1because of removal of surface‐adsorbed fluoride ions.With increasing calcination temperature from300to900°C,the building blocks of the TiO2‐HMSs evolve from truncated bipyramidal shaped hollow nanoparticles to round solid nanoparticles,and the photoreactivity of the TiO2‐HMSs steady increases from0.82×10?3to2.09×10?3min?1because of enhanced crystallization.Further increasing the calcination temperature to1000and1100°C results in a decrease of the photoreactivity,which is ascribed to a sharp decrease of the Brunauer–Emmett–Teller surface area and the beginning of the anatase–rutile phase transformation at1100°C.The effect of surface‐adsorbed fluoride ions on the thermal stability of the TiO2‐HMSs is also discussed.展开更多
Mefunidone （MFD）, a pirfenidone analogue, has been suggested as a novel anti-fibrotic agent in preclinical research stage. In this work, we developed a sensitive and specified HPLC-UV method and validated it for the...Mefunidone （MFD）, a pirfenidone analogue, has been suggested as a novel anti-fibrotic agent in preclinical research stage. In this work, we developed a sensitive and specified HPLC-UV method and validated it for the determination of MFD in rat plasma. A cost-effective protein precipitation method using methanol was used to process the plasma samples, and pirfenidone was employed as the internal standard （IS）. Chromatographic separation was performed on an Agilent ZORBAX SB-Aq column （4.6 mm 250 mm, 5 μm） with a mobile phase consisting of 10 mM ammonium formate solution （pH 3.0, adjusted by 1.5%o formic acid）-acetonitrile-methanol （60：23：17, v/v/v） at a flow rate of 1.0 mL/min, and the samples were monitored at an ultraviolet wavelength of 245 nm. The retention times of MFD and IS were 5.5 and 7.8 min, respectively. The calibration curve was linear （r2 = 0.9997） between 0.1 and 20 pg/mL. The intra- and inter-day precisions were within 8.6%, and the bias of intra- and inter-accuracies of the method was between -4.2% and 6.5%. The method was successfully applied to pharmacokinetic study of MFD after i.g. and i.v. administration in rats. The elimination half-life was （3.41±0.81） h for i.g. administration and （2.26±0.87） h for i.v. administration. The absolute bioavailability of MFD in rat was 79.1%.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.92156008,22161142016)the Taishan Scholar Program at Shandong Provincethe Natural Science Foundation of Shandong Province(No.ZR2020QB018)。
文摘Manganese-catalyzed C—C bond cleavage of cyclobutanols has attracted great attention due to the high abundance and cheap and eco-friendly behaviour.A manganese-catalyzed ring-opening C—C bond fluorination of cyclobutanols is reported.Under mild conditions,the reaction provides a straightforward access to γ-fluorinated ketones using 10 mol% Mn(OAc)_(2) as catalyst and electrophilic fluorination reagent,which was generated in situ from HF·Et 3N and PhIO,as fluorine source.The reaction has an excellent functional-group tolerance and displays a broad substrate scope,affording the corresponding products in 50%~76%yields.
基金Project supported by the National Natural Science Foundation of China (Nos.20375035 and 20527005)the Natural Science Foundation of Zhejiang Province (No.Z404105), China
文摘For preparing fluorinated quinolone antibiotic medicine locally used in stomatology, simultaneous determination of norfloxacin, ciprofloxacin, and enoxacin was carried out by multiphase ion chromatography with fluorescence detection. Quinolone antibiotics were separated by Dionex OmniPac PAX-500 column with an eluent of 15 mmol/L H2SO4 and 35% methanol （v/v） at a flow-rate of 1.0 ml/min and detected with fluorescence with excitation and emission wave lengths of 347 ran and 420 ran respectively. The detection limits （S/N=3） of norfloxacin, ciprofloxacin and enoxacin were 50, 105 and 80 ng/ml respectively. The relative standard deviations of retention time, peak area and peak height were less than 1.1% and good linear relationship resulted. The developed method was applied to pharmaceutical formulations and biological fluids.
基金supported by the National Natural Science Foundation of China(51672312,21373275)the Science and Technology Program of Wuhan,China(2016010101010018,2015070504020220)the Dean’s Research Fund–04257 from the Education University of Hong Kong~~
文摘TiO2hollow microspheres(TiO2‐HMSs)have attracted much attention because of their high photoreactivity,low density,and good permeability.However,anatase TiO2‐HMSs have poor thermal stability.In this study,surface‐fluorinated TiO2‐HMSs were assembled from hollow nanoparticles by the hydrothermal reaction of the mixed Ti(SO4)2–NH4HF–H2O2solution at180°C.The effect of the calcination temperature on the structure and photoreactivity of the TiO2‐HMSs was systematically investigated,which was evaluated by photocatalytic oxidation of acetone in air under ultraviolet irradiation.We found that after calcination at300°C,the photoreactivity of the TiO2‐HMSs decreases from1.39×10?3min?1(TiO2‐HMS precursor)to0.82×10?3min?1because of removal of surface‐adsorbed fluoride ions.With increasing calcination temperature from300to900°C,the building blocks of the TiO2‐HMSs evolve from truncated bipyramidal shaped hollow nanoparticles to round solid nanoparticles,and the photoreactivity of the TiO2‐HMSs steady increases from0.82×10?3to2.09×10?3min?1because of enhanced crystallization.Further increasing the calcination temperature to1000and1100°C results in a decrease of the photoreactivity,which is ascribed to a sharp decrease of the Brunauer–Emmett–Teller surface area and the beginning of the anatase–rutile phase transformation at1100°C.The effect of surface‐adsorbed fluoride ions on the thermal stability of the TiO2‐HMSs is also discussed.
基金National Natural Science Foundation of China(Grant No.81573498)supported by Nanxin Pharmaceutical Co.,Ltd.(Guangdong,China)
文摘Mefunidone （MFD）, a pirfenidone analogue, has been suggested as a novel anti-fibrotic agent in preclinical research stage. In this work, we developed a sensitive and specified HPLC-UV method and validated it for the determination of MFD in rat plasma. A cost-effective protein precipitation method using methanol was used to process the plasma samples, and pirfenidone was employed as the internal standard （IS）. Chromatographic separation was performed on an Agilent ZORBAX SB-Aq column （4.6 mm 250 mm, 5 μm） with a mobile phase consisting of 10 mM ammonium formate solution （pH 3.0, adjusted by 1.5%o formic acid）-acetonitrile-methanol （60：23：17, v/v/v） at a flow rate of 1.0 mL/min, and the samples were monitored at an ultraviolet wavelength of 245 nm. The retention times of MFD and IS were 5.5 and 7.8 min, respectively. The calibration curve was linear （r2 = 0.9997） between 0.1 and 20 pg/mL. The intra- and inter-day precisions were within 8.6%, and the bias of intra- and inter-accuracies of the method was between -4.2% and 6.5%. The method was successfully applied to pharmacokinetic study of MFD after i.g. and i.v. administration in rats. The elimination half-life was （3.41±0.81） h for i.g. administration and （2.26±0.87） h for i.v. administration. The absolute bioavailability of MFD in rat was 79.1%.
