The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
George Psomas - One of the best experts on this subject based on the ideXlab platform.
-
zinc ii complexes with the Quinolone Antibacterial drug flumequine structure dna and albumin binding
New Journal of Chemistry, 2013Co-Authors: Alketa Tarushi, Jakob Kljun, Iztok Turel, George Psomas, Anastasia A. Pantazaki, Dimitris P KessissoglouAbstract:The interaction of Zn(II) with the Quinolone Antibacterial drug flumequine (Hflmq) in the presence or absence of an N,N′-donor heterocyclic ligand, 2,2′-bipyridine (bipy), is being investigated. Interaction of equimolar quantities of ZnCl2 with flumequine and 2,2′-bipyridine results in the formation of a structurally characterized [Zn(flmq)(bipy)Cl] (2) complex, while excess of flumequine leads to a structurally characterized [Zn(flmq)2(bipy)] (3) compound. The reaction of ZnCl2 with flumequine in the absence of 2,2′-bipyridine leads to formation of complex [Zn(flmq)2(H2O)2] (1). In all these complexes, the deprotonated bidentate flumequinato ligands are coordinated to zinc ions through pyridone and carboxylato oxygens. The complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values. UV study of interaction of the complexes with calf-thymus DNA (CT DNA) has shown that they bind to CT DNA and [Zn(flmq)(bipy)Cl] exhibits the highest binding constant. A competitive study with ethidium bromide (EB) has shown that the complexes can displace DNA-bound EB, indicating that they bind to DNA in strong competition with EB. The complexes bind to CT DNA in an intercalative binding mode which has also been verified by DNA solution viscosity measurements. DNA electrophoretic mobility experiments showed that all complexes bind to pDNA possibly in an intercalative manner resulting in catenanes formation as well as in double-stranded cleavage reflecting (or ending) in the formation of linear DNA.
-
First- and second-generation Quinolone Antibacterial drugs interacting with zinc(II): structure and biological perspectives.
Journal of inorganic biochemistry, 2012Co-Authors: Alketa Tarushi, Jakob Kljun, Iztok Turel, George Psomas, Anastasia A. Pantazaki, K. Lafazanis, Dimitris P KessissoglouAbstract:Interaction of equimolar quantities of ZnCl2 with the Quinolone Antibacterial drugs flumequine (Hflmq), oxolinic acid (Hoxo) or enrofloxacin (Herx) and the N,N′-donor heterocyclic ligands 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) results in the formation of 1:1 drug to metal complexes with the general formula [Zn(Quinolone)(N,N′-donor)Cl], while excess of the Quinolone leads to 1:2 metal to drug [Zn(Quinolone)2(N,N′-donor)] complexes. In all complexes, the deprotonated bidentate quinolonato ligands are coordinated to zinc ion through the pyridone oxygen and a carboxylato oxygen. The crystal structures of [Zn(oxo)(phen)Cl], [Zn(flmq)(phen)Cl] and [Zn(flmq)2(phen)] have been determined by X-ray crystallography. All complexes exhibit good binding propensity to human or bovine serum albumin protein showing relatively high binding constant values. Interaction of the complexes with calf-thymus (CT) DNA, studied by UV spectroscopy, has shown that they bind to CT DNA, while [Zn(flmq)(phen)Cl] and [Zn(flmq)2(phen)] complexes exhibit the highest binding constants to CT DNA. Competitive study with ethidium bromide (EB) has shown that all complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. Intercalative binding mode is proposed for the interaction of the complexes with CT DNA and has also been verified by DNA solution viscosity measurements. DNA electrophoretic mobility experiments suggest that all complexes bind to linearized pDNA and supercoiled pDNA by intercalative manner resulting in catenanes formation as well as in double-stranded cleavage reflecting (or ending) in the formation of linear DNA. The complexes exhibit significant antimicrobial activity tested on five different microorganisms.
-
zinc ii complexes of the second generation Quinolone Antibacterial drug enrofloxacin structure and dna or albumin interaction
Bioorganic & Medicinal Chemistry, 2010Co-Authors: Alketa Tarushi, George Psomas, Catherine P. Raptopoulou, Vassilis Psycharis, Aris Terzis, Dimitris P KessissoglouAbstract:Zinc mononuclear complexes with the second-generation Quinolone Antibacterial drug enrofloxacin in the absence or presence of a nitrogen donor heterocyclic ligand 1,10-phenanthroline or 2,2′-bipyridine have been synthesized and characterized. Enrofloxacin is on deprotonated mode acting as a bidentate ligand coordinated to zinc ion through the ketone and a carboxylato oxygen atoms. The crystal structure of bis(enrofloxacinato)(1,10-phenanthroline)zinc(II), 2, has been determined by X-ray crystallography. The biological activity of the complexes has been evaluated by examining their ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies. UV studies of the interaction of the complexes with DNA have shown that they can bind to CT DNA and the DNA binding constants have been calculated. Competitive studies with ethidium bromide (EB) have shown that the complexes exhibit the ability to displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB for the intercalative binding site. The complexes exhibit good binding propensity to human and bovine serum albumin proteins having relatively high binding constant values.
-
mononuclear metal complexes of the second generation Quinolone Antibacterial agent enrofloxacin synthesis structure Antibacterial activity and interaction with dna
Polyhedron, 2008Co-Authors: Eleni K Efthimiadou, Alexandra Karaliota, George PsomasAbstract:Abstract Seven novel metal complexes of the second-generation Quinolone Antibacterial agent enrofloxacin with Mn2+, Fe3+, Co2+, Ni2+, Zn2+, Cd2+ and UO 2 2 + have been prepared and characterized with physicochemical methods and infrared, UV–Vis and nuclear magnetic resonance spectroscopies. In the resultant complexes, enrofloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone oxygen and one carboxylate oxygen. The central metal atoms are six-coordinate with slightly distorted octahedral geometry. Molecular modeling calculations have been performed in order to propose a model for the structure of Mn2+, Fe3+ and UO 2 2 + complexes. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with UV and circular dichroism spectroscopies. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes exhibit better or equal inhibition in comparison to free enrofloxacin.
-
mononuclear dioxomolybdenum vi complexes with the Quinolones enrofloxacin and sparfloxacin synthesis structure Antibacterial activity and interaction with dna
Polyhedron, 2008Co-Authors: Eleni K Efthimiadou, Alexandra Karaliota, George PsomasAbstract:The neutral mononuclear dioxomolybdenum(VI) complexes of the Quinolone Antibacterial agents enrofloxacin and sparfloxacin have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, enrofloxacin and sparfloxacin act as bidentate deprotonated ligands bound to the metal through the pyridone oxygen and one carboxylate oxygen. The central molybdenum atoms are six-coordinate with slightly distorted octahedral geometry. The lowest energy model structure of each complex has been proposed with molecular modeling calculations. The antimicrobial activity of the complexes has been tested on three different microorganisms. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques.
Eleni K Efthimiadou - One of the best experts on this subject based on the ideXlab platform.
-
mononuclear metal complexes of the second generation Quinolone Antibacterial agent enrofloxacin synthesis structure Antibacterial activity and interaction with dna
Polyhedron, 2008Co-Authors: Eleni K Efthimiadou, Alexandra Karaliota, George PsomasAbstract:Abstract Seven novel metal complexes of the second-generation Quinolone Antibacterial agent enrofloxacin with Mn2+, Fe3+, Co2+, Ni2+, Zn2+, Cd2+ and UO 2 2 + have been prepared and characterized with physicochemical methods and infrared, UV–Vis and nuclear magnetic resonance spectroscopies. In the resultant complexes, enrofloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone oxygen and one carboxylate oxygen. The central metal atoms are six-coordinate with slightly distorted octahedral geometry. Molecular modeling calculations have been performed in order to propose a model for the structure of Mn2+, Fe3+ and UO 2 2 + complexes. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with UV and circular dichroism spectroscopies. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes exhibit better or equal inhibition in comparison to free enrofloxacin.
-
mononuclear dioxomolybdenum vi complexes with the Quinolones enrofloxacin and sparfloxacin synthesis structure Antibacterial activity and interaction with dna
Polyhedron, 2008Co-Authors: Eleni K Efthimiadou, Alexandra Karaliota, George PsomasAbstract:The neutral mononuclear dioxomolybdenum(VI) complexes of the Quinolone Antibacterial agents enrofloxacin and sparfloxacin have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, enrofloxacin and sparfloxacin act as bidentate deprotonated ligands bound to the metal through the pyridone oxygen and one carboxylate oxygen. The central molybdenum atoms are six-coordinate with slightly distorted octahedral geometry. The lowest energy model structure of each complex has been proposed with molecular modeling calculations. The antimicrobial activity of the complexes has been tested on three different microorganisms. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques.
-
neutral mononuclear dioxomolybdenum vi and dioxouranium vi complexes of oxolinic acid characterization and biological evaluation
Inorganica Chimica Acta, 2007Co-Authors: Alketa Tarushi, Petros Christofis, Eleni K Efthimiadou, George PsomasAbstract:Abstract The interaction of the first-generation Quinolone Antibacterial drug oxolinic acid (Hoxo) with the dioxomolybdenum(VI) and dioxouranim(VI) ions leads to the formation of the neutral mononuclear complexes MoO 2 (oxo) 2 and UO 2 (oxo) 2 , respectively. The structure of the complexes has been characterized physicochemically and spectroscopically. The lowest energy model structure of the complexes has been determined with molecular modeling calculations. The antimicrobial activity of the complexes has been evaluated against three different microorganisms. The interaction of the complexes with calf-thymus DNA has been investigated with electronic and circular dichroism spectroscopies.
-
synthesis characterization Antibacterial activity and interaction with dna of the vanadyl enrofloxacin complex
Bioorganic & Medicinal Chemistry Letters, 2007Co-Authors: Eleni K Efthimiadou, Nikos Katsaros, Alexandra Karaliota, George PsomasAbstract:The neutral mononuclear vanadyl complex with the Quinolone Antibacterial drug enrofloxacin has been prepared and characterized with physicochemical and spectroscopic techniques and molecular mechanics calculations. The interaction of the complex with calf-thymus DNA has also been investigated and the antimicrobial activity has been evaluated against three different microorganisms.
-
metal complexes with the Quinolone Antibacterial agent n propyl norfloxacin synthesis structure and bioactivity
Journal of Inorganic Biochemistry, 2007Co-Authors: Eleni K Efthimiadou, George Psomas, Yiannis Sanakis, Nikos Katsaros, Alexandra KaraliotaAbstract:Abstract Nine new metal complexes of the Quinolone Antibacterial agent N -propyl-norfloxacin, pr-norfloxacin, with VO 2+ , Mn 2+ , Fe 3+ , Co 2+ , Ni 2+ , Zn 2+ , MoO 2 2 + , Cd 2+ and UO 2 2 + have been prepared and characterized with physicochemical and spectroscopic techniques while molecular mechanics calculations for Fe 3+ , VO 2+ and MoO 2 2 + complexes have been performed. In all complexes, pr-norfloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone and one carboxylate oxygen atoms. All complexes are six-coordinate with slightly distorted octahedral geometry. For the complex VO( N -propyl-norfloxacinato) 2 (H 2 O) the axial position, trans to the vanadyl oxygen, is occupied by one pyridone oxygen atom. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques and has shown that the complexes can be bound to calf-thymus DNA resulting to a B → A DNA transition. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes show equal or decreased biological activity in comparison to the free pr-norfloxacin except UO 2 (pr-norf) 2 which shows better inhibition against S. aureus .
Alexandra Karaliota - One of the best experts on this subject based on the ideXlab platform.
-
mononuclear metal complexes of the second generation Quinolone Antibacterial agent enrofloxacin synthesis structure Antibacterial activity and interaction with dna
Polyhedron, 2008Co-Authors: Eleni K Efthimiadou, Alexandra Karaliota, George PsomasAbstract:Abstract Seven novel metal complexes of the second-generation Quinolone Antibacterial agent enrofloxacin with Mn2+, Fe3+, Co2+, Ni2+, Zn2+, Cd2+ and UO 2 2 + have been prepared and characterized with physicochemical methods and infrared, UV–Vis and nuclear magnetic resonance spectroscopies. In the resultant complexes, enrofloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone oxygen and one carboxylate oxygen. The central metal atoms are six-coordinate with slightly distorted octahedral geometry. Molecular modeling calculations have been performed in order to propose a model for the structure of Mn2+, Fe3+ and UO 2 2 + complexes. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with UV and circular dichroism spectroscopies. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes exhibit better or equal inhibition in comparison to free enrofloxacin.
-
mononuclear dioxomolybdenum vi complexes with the Quinolones enrofloxacin and sparfloxacin synthesis structure Antibacterial activity and interaction with dna
Polyhedron, 2008Co-Authors: Eleni K Efthimiadou, Alexandra Karaliota, George PsomasAbstract:The neutral mononuclear dioxomolybdenum(VI) complexes of the Quinolone Antibacterial agents enrofloxacin and sparfloxacin have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, enrofloxacin and sparfloxacin act as bidentate deprotonated ligands bound to the metal through the pyridone oxygen and one carboxylate oxygen. The central molybdenum atoms are six-coordinate with slightly distorted octahedral geometry. The lowest energy model structure of each complex has been proposed with molecular modeling calculations. The antimicrobial activity of the complexes has been tested on three different microorganisms. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques.
-
synthesis characterization Antibacterial activity and interaction with dna of the vanadyl enrofloxacin complex
Bioorganic & Medicinal Chemistry Letters, 2007Co-Authors: Eleni K Efthimiadou, Nikos Katsaros, Alexandra Karaliota, George PsomasAbstract:The neutral mononuclear vanadyl complex with the Quinolone Antibacterial drug enrofloxacin has been prepared and characterized with physicochemical and spectroscopic techniques and molecular mechanics calculations. The interaction of the complex with calf-thymus DNA has also been investigated and the antimicrobial activity has been evaluated against three different microorganisms.
-
metal complexes with the Quinolone Antibacterial agent n propyl norfloxacin synthesis structure and bioactivity
Journal of Inorganic Biochemistry, 2007Co-Authors: Eleni K Efthimiadou, George Psomas, Yiannis Sanakis, Nikos Katsaros, Alexandra KaraliotaAbstract:Abstract Nine new metal complexes of the Quinolone Antibacterial agent N -propyl-norfloxacin, pr-norfloxacin, with VO 2+ , Mn 2+ , Fe 3+ , Co 2+ , Ni 2+ , Zn 2+ , MoO 2 2 + , Cd 2+ and UO 2 2 + have been prepared and characterized with physicochemical and spectroscopic techniques while molecular mechanics calculations for Fe 3+ , VO 2+ and MoO 2 2 + complexes have been performed. In all complexes, pr-norfloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone and one carboxylate oxygen atoms. All complexes are six-coordinate with slightly distorted octahedral geometry. For the complex VO( N -propyl-norfloxacinato) 2 (H 2 O) the axial position, trans to the vanadyl oxygen, is occupied by one pyridone oxygen atom. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques and has shown that the complexes can be bound to calf-thymus DNA resulting to a B → A DNA transition. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes show equal or decreased biological activity in comparison to the free pr-norfloxacin except UO 2 (pr-norf) 2 which shows better inhibition against S. aureus .
-
structure and biological properties of the copper ii complex with the Quinolone Antibacterial drug n propyl norfloxacin and 2 2 bipyridine
Journal of Inorganic Biochemistry, 2007Co-Authors: Eleni K Efthimiadou, Catherine P. Raptopoulou, Hellinida Thomadaki, Yiannis Sanakis, Nikos Katsaros, Andreas Scorilas, Alexandra Karaliota, George PsomasAbstract:Abstract The neutral mononuclear copper complex with the Quinolone Antibacterial drug N -propyl-protected norfloxacin, Hpr-norfloxacin, in the presence of the nitrogen donor heterocyclic ligand 2,2′-bipyridine has been prepared and characterized. The crystal structure of (chloro)(2,2′-bipyridine)(pr-norfloxacinato)copper(II), 1 , has been determined and refined with X-ray crystallography. X-band electron paramagnetic resonance (=EPR) spectroscopy at liquid helium temperatures from powdered samples indicates the presence of dimeric units in consistency with the crystal structure. In aqueous solutions of 1 the EPR behavior indicates mixture of dimeric and monomeric species. The antimicrobial activity of the complex has been tested on three different microorganisms and the best inhibition (MIC = 0.25 μg mL −1 ) has been exhibited against Escherichia coli . The study of the interaction of the complex with calf-thymus DNA has been performed with diverse spectroscopic techniques and has shown that complex 1 is bound to calf-thymus DNA by the intercalative mode. Potential anticancer cytostatic and cytotoxic effects of complex 1 on human promyelocytic leukemia HL-60 and human chronic myelogenous leukemia K562 cell lines have been investigated. Complex 1 shows an increased antiproliferative and necrotic effect on both HL-60 and K562 human leukemia cells in comparison to the free pr-norfloxacin.
Alketa Tarushi - One of the best experts on this subject based on the ideXlab platform.
-
zinc ii complexes with the Quinolone Antibacterial drug flumequine structure dna and albumin binding
New Journal of Chemistry, 2013Co-Authors: Alketa Tarushi, Jakob Kljun, Iztok Turel, George Psomas, Anastasia A. Pantazaki, Dimitris P KessissoglouAbstract:The interaction of Zn(II) with the Quinolone Antibacterial drug flumequine (Hflmq) in the presence or absence of an N,N′-donor heterocyclic ligand, 2,2′-bipyridine (bipy), is being investigated. Interaction of equimolar quantities of ZnCl2 with flumequine and 2,2′-bipyridine results in the formation of a structurally characterized [Zn(flmq)(bipy)Cl] (2) complex, while excess of flumequine leads to a structurally characterized [Zn(flmq)2(bipy)] (3) compound. The reaction of ZnCl2 with flumequine in the absence of 2,2′-bipyridine leads to formation of complex [Zn(flmq)2(H2O)2] (1). In all these complexes, the deprotonated bidentate flumequinato ligands are coordinated to zinc ions through pyridone and carboxylato oxygens. The complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values. UV study of interaction of the complexes with calf-thymus DNA (CT DNA) has shown that they bind to CT DNA and [Zn(flmq)(bipy)Cl] exhibits the highest binding constant. A competitive study with ethidium bromide (EB) has shown that the complexes can displace DNA-bound EB, indicating that they bind to DNA in strong competition with EB. The complexes bind to CT DNA in an intercalative binding mode which has also been verified by DNA solution viscosity measurements. DNA electrophoretic mobility experiments showed that all complexes bind to pDNA possibly in an intercalative manner resulting in catenanes formation as well as in double-stranded cleavage reflecting (or ending) in the formation of linear DNA.
-
First- and second-generation Quinolone Antibacterial drugs interacting with zinc(II): structure and biological perspectives.
Journal of inorganic biochemistry, 2012Co-Authors: Alketa Tarushi, Jakob Kljun, Iztok Turel, George Psomas, Anastasia A. Pantazaki, K. Lafazanis, Dimitris P KessissoglouAbstract:Interaction of equimolar quantities of ZnCl2 with the Quinolone Antibacterial drugs flumequine (Hflmq), oxolinic acid (Hoxo) or enrofloxacin (Herx) and the N,N′-donor heterocyclic ligands 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) results in the formation of 1:1 drug to metal complexes with the general formula [Zn(Quinolone)(N,N′-donor)Cl], while excess of the Quinolone leads to 1:2 metal to drug [Zn(Quinolone)2(N,N′-donor)] complexes. In all complexes, the deprotonated bidentate quinolonato ligands are coordinated to zinc ion through the pyridone oxygen and a carboxylato oxygen. The crystal structures of [Zn(oxo)(phen)Cl], [Zn(flmq)(phen)Cl] and [Zn(flmq)2(phen)] have been determined by X-ray crystallography. All complexes exhibit good binding propensity to human or bovine serum albumin protein showing relatively high binding constant values. Interaction of the complexes with calf-thymus (CT) DNA, studied by UV spectroscopy, has shown that they bind to CT DNA, while [Zn(flmq)(phen)Cl] and [Zn(flmq)2(phen)] complexes exhibit the highest binding constants to CT DNA. Competitive study with ethidium bromide (EB) has shown that all complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. Intercalative binding mode is proposed for the interaction of the complexes with CT DNA and has also been verified by DNA solution viscosity measurements. DNA electrophoretic mobility experiments suggest that all complexes bind to linearized pDNA and supercoiled pDNA by intercalative manner resulting in catenanes formation as well as in double-stranded cleavage reflecting (or ending) in the formation of linear DNA. The complexes exhibit significant antimicrobial activity tested on five different microorganisms.
-
zinc ii complexes of the second generation Quinolone Antibacterial drug enrofloxacin structure and dna or albumin interaction
Bioorganic & Medicinal Chemistry, 2010Co-Authors: Alketa Tarushi, George Psomas, Catherine P. Raptopoulou, Vassilis Psycharis, Aris Terzis, Dimitris P KessissoglouAbstract:Zinc mononuclear complexes with the second-generation Quinolone Antibacterial drug enrofloxacin in the absence or presence of a nitrogen donor heterocyclic ligand 1,10-phenanthroline or 2,2′-bipyridine have been synthesized and characterized. Enrofloxacin is on deprotonated mode acting as a bidentate ligand coordinated to zinc ion through the ketone and a carboxylato oxygen atoms. The crystal structure of bis(enrofloxacinato)(1,10-phenanthroline)zinc(II), 2, has been determined by X-ray crystallography. The biological activity of the complexes has been evaluated by examining their ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies. UV studies of the interaction of the complexes with DNA have shown that they can bind to CT DNA and the DNA binding constants have been calculated. Competitive studies with ethidium bromide (EB) have shown that the complexes exhibit the ability to displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB for the intercalative binding site. The complexes exhibit good binding propensity to human and bovine serum albumin proteins having relatively high binding constant values.
-
neutral mononuclear dioxomolybdenum vi and dioxouranium vi complexes of oxolinic acid characterization and biological evaluation
Inorganica Chimica Acta, 2007Co-Authors: Alketa Tarushi, Petros Christofis, Eleni K Efthimiadou, George PsomasAbstract:Abstract The interaction of the first-generation Quinolone Antibacterial drug oxolinic acid (Hoxo) with the dioxomolybdenum(VI) and dioxouranim(VI) ions leads to the formation of the neutral mononuclear complexes MoO 2 (oxo) 2 and UO 2 (oxo) 2 , respectively. The structure of the complexes has been characterized physicochemically and spectroscopically. The lowest energy model structure of the complexes has been determined with molecular modeling calculations. The antimicrobial activity of the complexes has been evaluated against three different microorganisms. The interaction of the complexes with calf-thymus DNA has been investigated with electronic and circular dichroism spectroscopies.
-
synthesis characterization and interaction with dna of mononuclear metal complexes with oxolinic acid
Polyhedron, 2007Co-Authors: Alketa Tarushi, Petros Christofis, George PsomasAbstract:Seven new neutral mononuclear metal complexes of VO2+, Mn2+, Fe3+, Co2+, Ni2+, Zn2+ and Cd2+ with the Quinolone Antibacterial agent oxolinic acid (=Hoxo) have been prepared and characterized with physicochemical and spectroscopic techniques. In all the complexes, oxolinic acid acts as a bidentate deprotonated ligand bound to the metal through the pyridone oxygen and one carboxylate oxygen. The metals in all the complexes are six-coordinate with slightly distorted octahedral geometry. The lowest energy model structures of the complexes Fe(oxo)3, VO(oxo)2(H2O) and Mn(oxo)2(H2O)2 have been determined with molecular modeling calculations. The ability of all the complexes to bind to calf-thymus DNA has been investigated with diverse spectroscopic techniques.
Dimitris P Kessissoglou - One of the best experts on this subject based on the ideXlab platform.
-
zinc ii complexes with the Quinolone Antibacterial drug flumequine structure dna and albumin binding
New Journal of Chemistry, 2013Co-Authors: Alketa Tarushi, Jakob Kljun, Iztok Turel, George Psomas, Anastasia A. Pantazaki, Dimitris P KessissoglouAbstract:The interaction of Zn(II) with the Quinolone Antibacterial drug flumequine (Hflmq) in the presence or absence of an N,N′-donor heterocyclic ligand, 2,2′-bipyridine (bipy), is being investigated. Interaction of equimolar quantities of ZnCl2 with flumequine and 2,2′-bipyridine results in the formation of a structurally characterized [Zn(flmq)(bipy)Cl] (2) complex, while excess of flumequine leads to a structurally characterized [Zn(flmq)2(bipy)] (3) compound. The reaction of ZnCl2 with flumequine in the absence of 2,2′-bipyridine leads to formation of complex [Zn(flmq)2(H2O)2] (1). In all these complexes, the deprotonated bidentate flumequinato ligands are coordinated to zinc ions through pyridone and carboxylato oxygens. The complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values. UV study of interaction of the complexes with calf-thymus DNA (CT DNA) has shown that they bind to CT DNA and [Zn(flmq)(bipy)Cl] exhibits the highest binding constant. A competitive study with ethidium bromide (EB) has shown that the complexes can displace DNA-bound EB, indicating that they bind to DNA in strong competition with EB. The complexes bind to CT DNA in an intercalative binding mode which has also been verified by DNA solution viscosity measurements. DNA electrophoretic mobility experiments showed that all complexes bind to pDNA possibly in an intercalative manner resulting in catenanes formation as well as in double-stranded cleavage reflecting (or ending) in the formation of linear DNA.
-
First- and second-generation Quinolone Antibacterial drugs interacting with zinc(II): structure and biological perspectives.
Journal of inorganic biochemistry, 2012Co-Authors: Alketa Tarushi, Jakob Kljun, Iztok Turel, George Psomas, Anastasia A. Pantazaki, K. Lafazanis, Dimitris P KessissoglouAbstract:Interaction of equimolar quantities of ZnCl2 with the Quinolone Antibacterial drugs flumequine (Hflmq), oxolinic acid (Hoxo) or enrofloxacin (Herx) and the N,N′-donor heterocyclic ligands 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) results in the formation of 1:1 drug to metal complexes with the general formula [Zn(Quinolone)(N,N′-donor)Cl], while excess of the Quinolone leads to 1:2 metal to drug [Zn(Quinolone)2(N,N′-donor)] complexes. In all complexes, the deprotonated bidentate quinolonato ligands are coordinated to zinc ion through the pyridone oxygen and a carboxylato oxygen. The crystal structures of [Zn(oxo)(phen)Cl], [Zn(flmq)(phen)Cl] and [Zn(flmq)2(phen)] have been determined by X-ray crystallography. All complexes exhibit good binding propensity to human or bovine serum albumin protein showing relatively high binding constant values. Interaction of the complexes with calf-thymus (CT) DNA, studied by UV spectroscopy, has shown that they bind to CT DNA, while [Zn(flmq)(phen)Cl] and [Zn(flmq)2(phen)] complexes exhibit the highest binding constants to CT DNA. Competitive study with ethidium bromide (EB) has shown that all complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. Intercalative binding mode is proposed for the interaction of the complexes with CT DNA and has also been verified by DNA solution viscosity measurements. DNA electrophoretic mobility experiments suggest that all complexes bind to linearized pDNA and supercoiled pDNA by intercalative manner resulting in catenanes formation as well as in double-stranded cleavage reflecting (or ending) in the formation of linear DNA. The complexes exhibit significant antimicrobial activity tested on five different microorganisms.
-
zinc ii complexes of the second generation Quinolone Antibacterial drug enrofloxacin structure and dna or albumin interaction
Bioorganic & Medicinal Chemistry, 2010Co-Authors: Alketa Tarushi, George Psomas, Catherine P. Raptopoulou, Vassilis Psycharis, Aris Terzis, Dimitris P KessissoglouAbstract:Zinc mononuclear complexes with the second-generation Quinolone Antibacterial drug enrofloxacin in the absence or presence of a nitrogen donor heterocyclic ligand 1,10-phenanthroline or 2,2′-bipyridine have been synthesized and characterized. Enrofloxacin is on deprotonated mode acting as a bidentate ligand coordinated to zinc ion through the ketone and a carboxylato oxygen atoms. The crystal structure of bis(enrofloxacinato)(1,10-phenanthroline)zinc(II), 2, has been determined by X-ray crystallography. The biological activity of the complexes has been evaluated by examining their ability to bind to calf-thymus DNA (CT DNA) with UV and fluorescence spectroscopies. UV studies of the interaction of the complexes with DNA have shown that they can bind to CT DNA and the DNA binding constants have been calculated. Competitive studies with ethidium bromide (EB) have shown that the complexes exhibit the ability to displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB for the intercalative binding site. The complexes exhibit good binding propensity to human and bovine serum albumin proteins having relatively high binding constant values.
