Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum （FCC1） was cultured in vitro by a modified method of Trager and Jensen. Ant...Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum （FCC1） was cultured in vitro by a modified method of Trager and Jensen. Antimalarial compounds were screened by microscopy-based assay and microfluorimetric method. Results DA79 and DA78 showed potent antimalarial activity against Plasmodiumfalciparum cultured in vitro. Conclusion Though the relationship between the structures of daphnetin derivatives and their antimalarial activities has not been clarified yet, this study may provide a new direction for discovery of more potential antimalarial compounds.展开更多
Fe-N/C is a promising oxygen reduction reaction(ORR)catalyst to substitute the current widely used precious metal platinum.Cost-effectively fabricating the Fe-N/C material with high catalytic activity and getting in-d...Fe-N/C is a promising oxygen reduction reaction(ORR)catalyst to substitute the current widely used precious metal platinum.Cost-effectively fabricating the Fe-N/C material with high catalytic activity and getting in-depth insight into the responsible catalytic site are of great significance.In this work,we proposed to use biomass,tea leaves waste,as the precursor to prepare ORR catalyst.By adding 5%FeCl3(wt%)into tea precursor,the pyrolysis product(i.e.,5%Fe-N/C)exhibited an excellent four-electron ORR activity,whose onset potential was only 10 m V lower than that of commercial Pt/C.The limiting current density of 5%Fe-N/C(5.75 m A/cm^(2))was even higher than Pt/C(5.44 m A/cm^(2)).Compared with other biomass or metal organic frameworks derived catalysts,5%Fe-N/C showed similar ORR activity.Also,both the methanol tolerance and material stability performances of as-prepared 5%Fe-N/C catalyst were superior to that of Pt/C.X-ray adsorption fine structure characterization revealed that the FeN4O2might be the possible catalytic site.An appropriate amount of iron chloride addition not only facilitated catalytic site formation,but also enhanced material conductivity and reaction kinetics.The results of this work may be useful for the Fe based transition metal ORR catalyst design and application.展开更多
Environmental endocrine disruptors,represented by bisphenol A(BPA),have been widely detected in the environment,bringing potential health risks to human beings.Nitrogen-containing biocarbon catalyst can activate perox...Environmental endocrine disruptors,represented by bisphenol A(BPA),have been widely detected in the environment,bringing potential health risks to human beings.Nitrogen-containing biocarbon catalyst can activate peroxymonosulfate(PMS)to degrade BPA in water,but its active sites remain opaque.Herein,in this work,nitrogen-containing biochar,i.e.,C–Nedge,enriched with graphitic-N defects at the edges was prepared by one-pot co-pyrolysis of chitosan and potassium carbonate.The results showed that the C–Nedge/PMS system can effectively degrade 98%of BPA(50 mg/L).The electron transfer based non-radical oxidation mechanism was responsible for BPA degradation.Edge graphitic-N doping endows biochar with strong electron transfer ability.The catalyst had good recovery and reuse performance.This catalytic oxidation was also feasible for other refractory pollutants removal and worked well for treating practical wastewater.This work may provide valuable information in unraveling the N doping configurationactivity relationship during activating PMS by biochar.展开更多
文摘Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum （FCC1） was cultured in vitro by a modified method of Trager and Jensen. Antimalarial compounds were screened by microscopy-based assay and microfluorimetric method. Results DA79 and DA78 showed potent antimalarial activity against Plasmodiumfalciparum cultured in vitro. Conclusion Though the relationship between the structures of daphnetin derivatives and their antimalarial activities has not been clarified yet, this study may provide a new direction for discovery of more potential antimalarial compounds.
基金the National Natural Science Foundation of China(No.51908172)for the support of this study。
文摘Fe-N/C is a promising oxygen reduction reaction(ORR)catalyst to substitute the current widely used precious metal platinum.Cost-effectively fabricating the Fe-N/C material with high catalytic activity and getting in-depth insight into the responsible catalytic site are of great significance.In this work,we proposed to use biomass,tea leaves waste,as the precursor to prepare ORR catalyst.By adding 5%FeCl3(wt%)into tea precursor,the pyrolysis product(i.e.,5%Fe-N/C)exhibited an excellent four-electron ORR activity,whose onset potential was only 10 m V lower than that of commercial Pt/C.The limiting current density of 5%Fe-N/C(5.75 m A/cm^(2))was even higher than Pt/C(5.44 m A/cm^(2)).Compared with other biomass or metal organic frameworks derived catalysts,5%Fe-N/C showed similar ORR activity.Also,both the methanol tolerance and material stability performances of as-prepared 5%Fe-N/C catalyst were superior to that of Pt/C.X-ray adsorption fine structure characterization revealed that the FeN4O2might be the possible catalytic site.An appropriate amount of iron chloride addition not only facilitated catalytic site formation,but also enhanced material conductivity and reaction kinetics.The results of this work may be useful for the Fe based transition metal ORR catalyst design and application.
基金National Natural Science Foundation of China(No.51908172)“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C03149)。
文摘Environmental endocrine disruptors,represented by bisphenol A(BPA),have been widely detected in the environment,bringing potential health risks to human beings.Nitrogen-containing biocarbon catalyst can activate peroxymonosulfate(PMS)to degrade BPA in water,but its active sites remain opaque.Herein,in this work,nitrogen-containing biochar,i.e.,C–Nedge,enriched with graphitic-N defects at the edges was prepared by one-pot co-pyrolysis of chitosan and potassium carbonate.The results showed that the C–Nedge/PMS system can effectively degrade 98%of BPA(50 mg/L).The electron transfer based non-radical oxidation mechanism was responsible for BPA degradation.Edge graphitic-N doping endows biochar with strong electron transfer ability.The catalyst had good recovery and reuse performance.This catalytic oxidation was also feasible for other refractory pollutants removal and worked well for treating practical wastewater.This work may provide valuable information in unraveling the N doping configurationactivity relationship during activating PMS by biochar.
