First Ni(Ⅱ)ternary complex using the quinolone antibacterial agent enoxacin(HEn)as ligand and 1,10-phenanthroline as co-ligand has been synthesized and characterized.It is a mononuclear structure,in which enoxacin ac...First Ni(Ⅱ)ternary complex using the quinolone antibacterial agent enoxacin(HEn)as ligand and 1,10-phenanthroline as co-ligand has been synthesized and characterized.It is a mononuclear structure,in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom.The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants(6.40×10^(4) and 7.12×10^(4),respectively).The investigation of the interaction of the complex with calf-thymus(CT)DNA has been performed with UV and circular dichroism(CD)spectroscopies,indicating that they bind to CT DNA probably by the intercalative binding mode.The binding constant(K_(b))of the complex with CT DNA calculated with UV is 2.03×10^(5),which is higher than that of free enoxacin drug(2.09×10^(4))and even higher than that of typical intercalation indicator(1.23×10^(5))of ethidium bromide(EB).Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA-bound EB using the intercalative binding site.In addition,the antimicrobial activity showed that the complex exhibited a little bit good inhibition(MIC=1.843μg•mL^(-1))against B.subtilis than free HEn.展开更多
A novel 1,8-naphthalimide-based OFF-ON type fluorogenic sydnone(Naph-Syd) is designed as bioorthogonal probe for imaging.Sydnone moiety efficiently quenches the native fluorescence of 1,8-naphthalimide,which can be re...A novel 1,8-naphthalimide-based OFF-ON type fluorogenic sydnone(Naph-Syd) is designed as bioorthogonal probe for imaging.Sydnone moiety efficiently quenches the native fluorescence of 1,8-naphthalimide,which can be restored with the enhancement of about 300-fold,after reacting with strained cyclooctynes to form pyrazole products(Naph-Pyr).The second-order rate constant of this bioorthogonal cycloaddition can be up to 2.5 L mol^-1s^-1,which benefits imaging of biomolecules at low concentrations in cellular environment.展开更多
基金The authors thank the financial support by Jiangsu National Science Foundation(No.BK2009239)The project was also funded by the Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources(Guangxi Normal University)the Ministry of Education of China(No.CMEMR2013-B02).
文摘First Ni(Ⅱ)ternary complex using the quinolone antibacterial agent enoxacin(HEn)as ligand and 1,10-phenanthroline as co-ligand has been synthesized and characterized.It is a mononuclear structure,in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom.The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants(6.40×10^(4) and 7.12×10^(4),respectively).The investigation of the interaction of the complex with calf-thymus(CT)DNA has been performed with UV and circular dichroism(CD)spectroscopies,indicating that they bind to CT DNA probably by the intercalative binding mode.The binding constant(K_(b))of the complex with CT DNA calculated with UV is 2.03×10^(5),which is higher than that of free enoxacin drug(2.09×10^(4))and even higher than that of typical intercalation indicator(1.23×10^(5))of ethidium bromide(EB).Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA-bound EB using the intercalative binding site.In addition,the antimicrobial activity showed that the complex exhibited a little bit good inhibition(MIC=1.843μg•mL^(-1))against B.subtilis than free HEn.
基金financially supported by the National Natural Science Foundation of China (No.21803030)the National Thousand Young Talents Program+1 种基金the Jiangsu Specially-Appointed Professor Planthe NSF of Jiangsu Province (No.BK20170631) in China
文摘A novel 1,8-naphthalimide-based OFF-ON type fluorogenic sydnone(Naph-Syd) is designed as bioorthogonal probe for imaging.Sydnone moiety efficiently quenches the native fluorescence of 1,8-naphthalimide,which can be restored with the enhancement of about 300-fold,after reacting with strained cyclooctynes to form pyrazole products(Naph-Pyr).The second-order rate constant of this bioorthogonal cycloaddition can be up to 2.5 L mol^-1s^-1,which benefits imaging of biomolecules at low concentrations in cellular environment.
