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1.
Foods ; 13(11)2024 May 25.
Article in English | MEDLINE | ID: mdl-38890882

ABSTRACT

Potato is a globally significant crop, crucial for food security and nutrition. Assessing vital nutritional traits is pivotal for enhancing nutritional value. However, traditional wet lab methods for the screening of large germplasms are time- and resource-intensive. To address this challenge, we used near-infrared reflectance spectroscopy (NIRS) for rapid trait estimation in diverse potato germplasms. It employs molecular absorption principles that use near-infrared sections of the electromagnetic spectrum for the precise and rapid determination of biochemical parameters and is non-destructive, enabling trait monitoring without sample compromise. We focused on modified partial least squares (MPLS)-based NIRS prediction models to assess eight key nutritional traits. Various mathematical treatments were executed by permutation and combinations for model calibration. The external validation prediction accuracy was based on the coefficient of determination (RSQexternal), the ratio of performance to deviation (RPD), and the low standard error of performance (SEP). Higher RSQexternal values of 0.937, 0.892, and 0.759 were obtained for protein, dry matter, and total phenols, respectively. Higher RPD values were found for protein (3.982), followed by dry matter (3.041) and total phenolics (2.000), which indicates the excellent predictability of the models. A paired t-test confirmed that the differences between laboratory and predicted values are non-significant. This study presents the first multi-trait NIRS prediction model for Indian potato germplasm. The developed NIRS model effectively predicted the remaining genotypes in this study, demonstrating its broad applicability. This work highlights the rapid screening potential of NIRS for potato germplasm, a valuable tool for identifying trait variations and refining breeding strategies, to ensure sustainable potato production in the face of climate change.

2.
Heliyon ; 8(5): e09373, 2022 May.
Article in English | MEDLINE | ID: mdl-35592663

ABSTRACT

A series of four copper(II) µ-Alkoxo-µ-carboxylato double bridged complexes, [{Cu2(L)}2][(µ-O2C-CO2] 1, [{Cu2(L)}2(µ-O2C-(CH2)CO2] 2, [{Cu2(L)}2(µ-O2C-CH2-CO2] 3 and [{Cu2(L)}2(µ-O2C-C6H4-CO2] 4 (H3L = 4-bromo-2-((E)-((3-(((E)-5-chloro-2-hydroxybenzylidene) amino)-2-hydroxypropyl) imino) methyl)-6-methoxyphenol and µ-dicarboxylate ions = oxalate, malonate, succinate and terephthalate) have been synthesized and characterized using several physicochemical techniques. The tridentate nature of H3L is interpreted from IR spectra. The Epr spectra of these complexes are characteristic of the quintet state (S = 2) in central features and the triplet state (S = 1) of these tetranuclear complexes. The electrochemical potential of these complexes was investigated using CV (cyclic voltammetry) and DPV (differential pulse voltammetry). All complexes showed quasi reversible reduction peaks in the cathodic region. To explore the stability of these complexes, quantum chemical parameters like electronegativity, ionization potential, electron affinity, global hardness and softness, and electrophilicity were estimated and discussed. The synthesized complexes have been designed as structural and functional models of the catechol oxidase enzymes to investigate the catecholase activity. Additionally, superoxide dismutase activity data of all complexes have also been evaluated and compared with known SOD mimics.

3.
Acta Crystallogr E Crystallogr Commun ; 78(Pt 2): 98-102, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-35145731

ABSTRACT

A tetra-nuclear complex with an open-cubane-like core structure was synthesized from 2-meth-oxy-6-(pyridin-2-yl-hydrazonometh-yl)phenol (HL), namely, cyclo-tetra-kis-(µ-2-meth-oxy-6-{[2-(pyridin-2-yl)hydrazin-1-yl-idene]meth-yl}pheno-lato)tetra-nickel(II) tetra-kis-(perchlorate) aceto-nitrile monosolvate dihydrate, [Ni4(C13H12N3O2)4](ClO4)4·C2H3N·2H2O, and characterized using micro-analytical and spectroscopic techniques. The crystal-structure determination reveals the formation of a distorted Ni4O4 cubane-like core architecture encapsulated by four hydrazone Schiff base (HL) mol-ecules. A open-cube tetra-nuclear architecture is created in which nickel(II) ions of the NiN2O3 unit are connected by µ2-O anions of the phenolate moiety of HL. In this complex, each Ni centre has a slightly distorted square-pyramidal coordination environment. The supra-molecular architectures are stabilized via the presence of various inter-molecular hydrogen bonds and (ar-yl-aryl, ar-yl-chelate and chelate-chelate) stacking inter-actions.

4.
Community Dent Health ; 33(4): 286-291, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28537366

ABSTRACT

AIM: The aim of this study was to investigate the methods used to identify national mean DMFT scores for 12-year-old children in all the Member States of the European Union and European Economic Area, and in 11 other European countries. METHODS: The most recent national mean DMFT scores were accessed from the World Health Organisation Oral Health CAPP and the Council of European Chief Dental Officers databanks. A literature search was then performed to access the reports of the studies that had produced these DMFT scores, cited on these databanks. The reports were then analysed to determine: the year in which the survey/study that produced the score took place, the year the results were published, the geographical area (national, regional or local) covered, the number of children examined, how many examiners took part, how they were trained and calibrated, and the criteria used for the detection of caries. RESULTS: Data and information from 43 European countries were accessed. The years when the studies were performed ranged from 1990 to 2014. There were doubts over the representativeness of some samples. A wide range of different methods were used. Examiner training and calibration were very variable both in terms of duration and reported inter and intra-examiner consistency. There were important variations in the criteria employed for the detection of caries. CONCLUSIONS: These findings support the view that most of current national caries data for DMFT levels in 12-year-old children are not comparable across Europe.


Subject(s)
DMF Index , Child , Dental Caries/epidemiology , Europe/epidemiology , Female , Humans , Male , Prevalence , Registries
6.
Community Dent Health ; 30(3): 189-95, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24151795

ABSTRACT

THE OBJECTIVE: To evaluate oral health-related quality of life (OHRQoL) in non-syndromic patients with cleft lip and/or palate (CLP), in comparison to a general non-cleft population. BASIC RESEARCH DESIGN: Systematic review. A literature search was conducted to identify papers reporting on OHRQoL in cleft samples. Only studies with suitable control groups were included. From each included paper were extracted the study and sample characteristics and results. MAIN OUTCOME MEASURES: OHRQoL score. RESULTS: Three papers were chosen according to the preset inclusion and exclusion criteria. All used an OHRQoL generic patient-reported questionnaire with evidence of a development and validation process, with responses recorded on a five-point scale. The results could not be combined for the purposes of meta-analysis due to lack of standardisation. In 2 of the 3 studies, the OHRQoL was found to be significantly lower in the cleft than in the non-cleft samples (in patients 8-18 or 18-65 years of age). The third study, based on a relatively small sample size, could not detect significant differences between cleft and non-cleft individuals. CONCLUSIONS: Based on the results of the few studies included in the present systematic review, non-syndromic patients with CLP tend to have a lower OHRQoL than a general non-cleft population. This seems to hold true both for children and adults.


Subject(s)
Cleft Lip/psychology , Cleft Palate/psychology , Quality of Life , Adolescent , Adult , Aged , Case-Control Studies , Child , Cross-Sectional Studies , Data Collection , Humans , Information Storage and Retrieval , Middle Aged , Surveys and Questionnaires , Young Adult
7.
Enzyme Microb Technol ; 48(6-7): 445-53, 2011 May 06.
Article in English | MEDLINE | ID: mdl-22113015

ABSTRACT

N-Cbz-4,5-dehydro-L-prolineamide or N-Boc-4,5-dehydro-L-prolineamide are alternative key intermediates for the synthesis of saxagliptin, a dipeptidyl peptidase IV (DPP4) inhibitor recently approved for treatment of type 2 diabetes mellitus. An efficient biocatalytic method was developed for conversion of L-ornithine, N-α-benzyloxycarbonyl (Cbz)-L-ornthine, and N-α-tert-butoxycarbonyl (Boc)-L-ornithine to 5-hydroxy-L-proline, N-Cbz-5-hydroxy-L-proline, and N-Boc-5-hydroxy-L-proline, respectively. Rec. Escherichia coli expressing lysine-ε-aminotransferase and rec Pichia pastoris expressing L-ornithine oxidase were used for these conversions. N-Cbz-5-hydroxy-L-proline, and N-Boc-5-hydroxy-L-proline were chemically converted to key intermediates N-Cbz-4,5-dehydro-L-prolineamide and N-Boc-4,5-dehydro-L-prolineamide, respectively.


Subject(s)
Adamantane/analogs & derivatives , Bacterial Proteins/metabolism , Dipeptides/biosynthesis , Fungal Proteins/metabolism , L-Amino Acid Oxidase/metabolism , L-Lysine 6-Transaminase/metabolism , Ornithine/metabolism , Proline/analogs & derivatives , Amino Acid Sequence , Base Sequence , Biocatalysis , Chromatography, High Pressure Liquid , Escherichia coli/enzymology , Fungal Proteins/genetics , Fungal Proteins/isolation & purification , Genes, Fungal , Hypoglycemic Agents , L-Amino Acid Oxidase/genetics , L-Amino Acid Oxidase/isolation & purification , Molecular Sequence Data , Ornithine/analogs & derivatives , Pichia/enzymology , Pichia/isolation & purification , Proline/metabolism , Recombinant Fusion Proteins/metabolism , Soil Microbiology , Sphingomonas/enzymology , Sphingomonas/genetics
8.
Article in English | MEDLINE | ID: mdl-16876473

ABSTRACT

A series of ternary copper(II) complexes containing same coordination sphere but difference in the counter ions, viz., [Cu(PMDT)(OAc)]PF(6)(1); [Cu(PMDT)(OAc)]ClO(4)(2); [Cu(PMDT)(OAc)]BF(4)(3) and [Cu(PMDT)(OAc)]BPh(4)(4) where PMDT=N,N,N',N'',N''-pentamethyldiethylenetriamine, OAc=Acetate ion were synthesized and characterized by means of spectroscopic, magnetic and cyclic voltammetric measurements. In frozen solution e.p.r. spectra, an interesting relation g|| >g(perpendicular) has been observed which is atypical of the axially symmetric d(9) Cu(II) (S(Cu)=1/2) having an unpaired electron in a d (x2-y2) orbital. Single crystal X-ray analysis of (1) has revealed the presence of distorted square planar geometry. The influence of the counter ion on the complexes has been examined by performing some biological experiments like superoxide dismutase and anti-microbial activity.


Subject(s)
Bacteria/drug effects , Copper/pharmacology , Fungi/drug effects , Organometallic Compounds/pharmacology , Polyamines/pharmacology , Superoxide Dismutase/metabolism , Copper/chemistry , Crystallography, X-Ray , Electron Spin Resonance Spectroscopy , Humans , Magnetics , Microbial Sensitivity Tests , Polyamines/chemistry , Spectrophotometry, Ultraviolet
9.
Article in English | MEDLINE | ID: mdl-16307903

ABSTRACT

Ternary copper(II) complexes involving polypyridyl ligands in the coordination sphere of composition [Cu(tpy)(phen)](ClO4)2 (1), [Cu(tpy)(bipy)](ClO4)2 (2), [Cu(tptz)(phen)](ClO4)2 (3) and [Cu(tptz)(bipy)](BF4)2 (4) where tpy = 2,2':6',2''-terpyridine, tptz = 2,4,6-tri(2-pyridyl)-1,3,5-triazine, phen = 1,10-phenanthroline and bipy = 2,2'-bipyridine have been synthesized and characterized by elemental analysis, magnetic susceptibility, X-band e.p.r. spectroscopy and electronic spectroscopy. Single crystal X-ray of (1) has revealed the presence of a distorted square pyramidal geometry in the complex. Magnetic susceptibility measurements at room temperature were in the range of 1.77-1.81 BM. SOD and antimicrobial activities of these complexes were also measured. Crystal data of (1): P-1, a = 9.3010(7) A, b = 9.7900(6) A, c = 16.4620(6) A, Vc = 1342.73(14) A3, Z = 4. The bond distance of CuN in square base is 2+/-0.04 A.


Subject(s)
Anti-Bacterial Agents/chemistry , Antifungal Agents/chemistry , Copper/chemistry , Organometallic Compounds/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/pharmacology , Bacteria/drug effects , Crystallography, X-Ray , Fungi/drug effects , Ligands , Microscopy, Electron , Molecular Structure , Organometallic Compounds/chemical synthesis , Organometallic Compounds/pharmacology , Superoxide Dismutase/chemistry
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 62(1-3): 261-8, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16257723

ABSTRACT

Two new mixed ligand copper(II) complexes with diethylenetriamine, 2,2'-bipyridine and 1,10-phenanthroline have been synthesized. The crystal and molecular structures of [Cu(dien)(phen)](ClO(4))(2) and [Cu(dien)(bipy)](BF(4))(2) (dien=diethylenetriamine, phen=1,10-phenanthroline, bipy=2,2'-bipyridine) were determined by X-ray crystallography from single crystal data. These two complexes have similar structures. The EPR spectral data also suggest that these complexes have distorted square pyramidal geometry about copper(II). Anti-microbial and superoxide dismutase activities of these complexes have also been measured. They show the higher SOD activity than the corresponding simple Cu(II)-dien/Cu(II)-PMDT (PMDT=N,N,N',N',N''-pentamethyldiethylenetriamine) complexes because of a strong axial bond of one of the nitrogen atoms of the alpha-diimine. Both the complexes have been found to cleave plasmid DNA in the presence of co-reductants such as ascorbic acid and glutathione.


Subject(s)
Copper/chemistry , Phenanthrolines/chemistry , Polyamines/chemistry , Anti-Bacterial Agents/pharmacology , Copper/pharmacology , Crystallography, X-Ray , Electron Spin Resonance Spectroscopy , Escherichia coli/drug effects , Kinetics , Ligands , Microbial Sensitivity Tests , Models, Molecular , Molecular Conformation , Phenanthrolines/pharmacology , Plasmids/metabolism , Polyamines/pharmacology , Proteus/drug effects , Pseudomonas/drug effects , Salmonella/drug effects , Staphylococcus/drug effects , Superoxide Dismutase/metabolism
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(11-12): 2603-10, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16043054

ABSTRACT

X-band electron spin resonance (ESR) and UV-vis spectra of a homobinuclear [(Bipy)2Cu-E-Im-Cu(Bipy)2](BF4)3 and a heterobinuclear [(Bipy)2Cu-E-Im-Zn(Bipy)2](BF4)3 complexes, E-Im=2-ethylimidazolate ion have been described as possible models for superoxide dismutase (SOD). Magnetic moment and ESR spectral measurements of the homobinuclear complex have shown an antiferromagnetic exchange interaction. From pH-dependent ESR and UV-vis spectral measurements studies, these complexes have been found to be stable over 8.5-10.5 pH range. These complexes catalyze the dismutation of superoxide (O2-) at biological pH. All the observations indicate that these complexes act as good possible models for superoxide dismutase.


Subject(s)
Biomimetic Materials/chemical synthesis , Biomimetic Materials/pharmacology , Copper/chemistry , Organometallic Compounds/chemistry , Zinc/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Biomimetic Materials/chemistry , Color , Dimethyl Sulfoxide , Electron Spin Resonance Spectroscopy , Hydrogen-Ion Concentration , Magnetics , Molecular Structure , Proteus vulgaris/drug effects , Solutions/chemistry , Spectrophotometry , Superoxide Dismutase/metabolism , Superoxides/chemistry , Superoxides/metabolism
12.
Article in English | MEDLINE | ID: mdl-15863062

ABSTRACT

X-band E.S.R., magnetic and electronic spectra of some imidazolate-bridged homometallic complexes [(en)2Cu-R-Im-Cu(en)2](ClO4)3 where en, ethylenediamine; R-ImH, R = H imidazole (ImH); if R = CH3, 2-methylimidazole (M-ImH) and if R = C2H5, 2-ethylimidazole (E-ImH), and mononuclear complexes [(en)Cu-dien](ClO4)2 and [(en)Cu-PMDT](ClO4)2 where dien, diethylenetriamine; PMDT, pentamethyldiethylenetriamine have been described. Superoxide dismutase (SOD) activity has also been measured and compared with earlier reported complexes. In frozen solution at 77 K, the spectra show axial symmetry with a d(x2-y2) ground state. Difference in lambda(max) between mononuclear and binuclear complexes was found to be approximately 65-75 nm. Magnetic susceptibility and E.S.R. spectral measurements for all these binuclear complexes revealed that the copper(II) ions are involved in antiferromagnetic exchange interactions propagated by the imidazolate bridge.


Subject(s)
Copper/chemistry , Electron Spin Resonance Spectroscopy/methods , Ethylenediamines/chemistry , Imidazoles/chemistry , Organometallic Compounds/chemistry , Superoxide Dismutase/chemistry , Binding Sites , Electromagnetic Fields , Electrons , Hydrogen-Ion Concentration , Inhibitory Concentration 50 , Ligands , Magnetics , Models, Chemical , Molecular Conformation , Spectrophotometry , Superoxides/chemistry , Temperature
13.
Article in English | MEDLINE | ID: mdl-15866489

ABSTRACT

A novel amide based chiral stationary phase m-[(+)-alpha-methyl benzyl carboxamide] XAD-4 has been synthesized by covalently linking R(+)-1-phenylethylamine to chloroformoyl Amberlite XAD-4 under weak alkaline conditions. The synthesized resin has been primarily characterized by m.p., elemental analysis and FT-IR and 13C NMR spectra. beta-Blockers viz. atenolol, metoprolol, and propranolol were successfully separated into their enantiomers using a mixture of sodium acetate-acetic acid buffer (pH 4.1):acetonitrile (4:6, v/v) solution using the synthesized resin. Hydrogen bonding and pi-pi interactions are supposed to be the major analyte-chiral stationary phase interactions.


Subject(s)
Adrenergic beta-Antagonists/isolation & purification , Chromatography, Liquid/methods , Chromatography, Liquid/instrumentation , Polystyrenes/chemistry , Polyvinyls/chemistry , Reproducibility of Results , Stereoisomerism
14.
J Inorg Biochem ; 99(2): 651-63, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15621300

ABSTRACT

Four imidazolate-bridged binuclear copper(II)-copper(II) and copper(II)-zinc(II) complexes viz., [(Bipy)(2)Cu-Im-Cu(Bipy)(2)](ClO(4))(3).CH(3)OH, [(Phen)(2)Cu-Im-Cu(Phen)(2)](BF(4))(3).2CH(3)OH, [(Bipy)(2)Cu-Im-Zn(Bipy)(2)](BF(4))(3), and [(Phen)(2)Cu-Im-Zn(Phen)(2)](BF(4))(3), (Bipy=2,2'-Bipyridyl, Phen=1-10-Phenanthroline and Im=imidazolate ion) were synthesized as a possible models for superoxide dismutase (SOD). Complex [(Bipy)(2)Cu-Im-Cu(Bipy)(2)](ClO(4))(3).CH(3)OH has been structurally characterized. This complex crystallizes in the triclinic space group P1, with the unit parameters a=8.88(5) A, b=13.79(17) A, c=20.18(18) A, alpha=76.424(8)(o), beta=85.888(6)(o), gamma=82.213(7). The metal-nitrogen bond length from 1.972-2.273 A and the distance Cu-Cu is 5.92 A. The five-coordinate geometry about the copper(II) ion is square pyramidal. Magnetic moment and electron paramagnetic resonance (e.p.r.) spectral measurements of the homobinuclear complexes have shown an antiferromagnetic exchange interaction. From the e.p.r. and UV-Vis spectral measurement studies, these complexes have been found to be stable (pH 8.5-10.5 for 1, 10.5 for 2,3 and 8.5 for 4). These complexes catalyse the dismutation of superoxide radical (O(2)(-)) at biological pH. All the observations indicate that these complexes act as good possible models for superoxide dismutase.


Subject(s)
Copper/chemistry , Organometallic Compounds/chemistry , Organometallic Compounds/chemical synthesis , Superoxide Dismutase/chemistry , Zinc/chemistry , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Catalytic Domain , Cattle , Crystallography, X-Ray , Electron Spin Resonance Spectroscopy , In Vitro Techniques , Models, Chemical , Molecular Structure , Organometallic Compounds/pharmacology , Spectrometry, Mass, Fast Atom Bombardment , Spectrophotometry
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(1-2): 287-97, 2005 Jan 01.
Article in English | MEDLINE | ID: mdl-15556452

ABSTRACT

The imidazolate-bridged binuclear copper(II)-copper(II) complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) and related mononuclear complexes [Cu(dien)(H(2)O)](ClO(4))(2), [Cu(dien)(Him)](ClO(4))(2) were synthesized with diethylenetriamine (dien) as capping ligand. The crystal structure of mononuclear [Cu(dien)(Him)](ClO(4))(2) and binuclear complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) have been determined by single crystal X-ray diffraction methods. The mononuclear complex [Cu(dien)(Him)](ClO(4))(2) crystallizes in the orthorhombic, Pca2(1) with a = 9.3420(9) A, b = 12.3750(9) A, c = 14.0830(9) A, beta = 90.000(7)(o) and Z = 4 and binuclear complex [(dien)Cu(mu-im)Cu(dien)](ClO(4))(3) crystallizes in the monoclinic space group P2(1)/a, with a = 15.017(7) A, b = 11.938(6) A, c = 15.386(6) A, beta = 110.30(4)(o) and Z = 4. The molecular structures show that copper(II) ions in an asymmetrically elongated octahedral coordination (type 4 + 1 + 1) and in binuclear complex Cu(1) atom has a asymmetrically elongated octahedral coordination (type type 4 + 1 + 1) and Cu(2) atom exhibits a square base pyramidal coordination (type 4 + 1). The bridging ligand (imidazolate ion, im) lies nearly on a straight line between two Cu(2+), which are separated by 5.812 A, slightly shorter than the value in copper-copper superoxide dismutase (Cu(2)-Cu(2)SOD). Magnetic measurements and electron spin resonance (ESR) spectroscopy of the binuclear complex have shown an antiferromagnetic exchange interaction. From pH-dependent cyclic voltametry (CV) and electronic spectroscopic studies the complex has been found to be stable over a wide pH range (7.75-12.50).


Subject(s)
Copper/chemistry , Models, Chemical , Organometallic Compounds/chemistry , Superoxide Dismutase/chemistry , Absorption , Anti-Bacterial Agents/pharmacology , Carbon/chemistry , Crystallography, X-Ray , Electrochemistry , Electrodes , Electron Spin Resonance Spectroscopy , Glass , Hydrogen-Ion Concentration , Magnetics , Molecular Conformation , Molecular Structure , Organometallic Compounds/chemical synthesis , Organometallic Compounds/pharmacology , Solutions , Superoxide Dismutase/metabolism
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 60(10): 2201-8, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15249006

ABSTRACT

The synthesis and characterization of homobinuclear complex by 2-ethylimidazole is reported along with two mononuclear complexes. Magnetic measurements and electron parameter resonance (e.p.r.) spectroscopy of the homobinuclear complex have shown an antiferromagnetic exchange interaction. Superoxide dismutase and antimicrobial activities of these complexes have also been measured.


Subject(s)
Copper/chemistry , Electron Spin Resonance Spectroscopy , Superoxide Dismutase/chemistry , Ethylenediamines , Models, Molecular , Spectrophotometry
17.
J Inorg Biochem ; 98(2): 231-7, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14729303

ABSTRACT

X-band electron spin resonance (ESR) and electronic spectra of oxalatobridged heterodinuclear Cu-Ni and Cu-Zn complexes, viz., [(PMDT)Cu-Ox-Ni(PMDT)](BPh(4))(2).2CH(3)CN and [(PMDT)Cu-Ox-Zn(PMDT)](BPh(4))(2).2CH(3)CN, where PMDT=pentamethyldiethylenetriamine, Ox=oxalate ion have been described. Complex [(PMDT)Cu-Ox-Ni(PMDT)](BPh(4))(2).2CH(3)CN has been structurally characterized. This complex crystallizes in the monoclinic space group, C(2) (No. 5) with the unit parameters a=20.445(4) A, b=14.884(3) A, c=23.174(5) A, alpha=90 degrees, beta=102.693(4) degrees, gamma=90 degrees, V=6880(2) A(3) and Z=4. The structure refined to R=0.0354 and R(w)=0.0853 for 21,109 reflections with I>2 sigma(I) using 765 parameters, shows the presence of a MN(3)O(2) chromophore in a distorted trigonal-bipyramidal (TBP) heterometallic complex with oxalate dianion. Taking with an equatorial Cu-O=2.137(8) A and an axial Cu-O=1.961(6) A coordination site at Cu(II) ion and equatorial Ni-O=2.178(7) A and axial Ni-O=1.994 (9) A coordination site at Ni(II) ion. The Cu-Ni distance is 5.3532(9) A and Cu-C(2)O(4)-Ni unit is planar. The [(PMDT)Cu-Ox-Ni(PMDT)](2+) shows the ESR spectrum of the antiferromagnetic spin exchange with each dinuclear delocalization of the unpaired electron over the unit and spin-doublet ground state which demonstrates the Cu-Ox-Ni core. Antimicrobial and superoxide dismutase (SOD) activities of these complexes have also been measured.


Subject(s)
Anti-Bacterial Agents/chemistry , Organometallic Compounds/chemistry , Superoxide Dismutase/metabolism , Animals , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Copper/chemistry , Copper/metabolism , Crystallography, X-Ray , Electron Spin Resonance Spectroscopy , Metals, Heavy/chemistry , Metals, Heavy/metabolism , Nickel/chemistry , Nickel/metabolism , Organometallic Compounds/metabolism , Organometallic Compounds/pharmacology , Oxalates/chemistry , Oxalates/metabolism , Spectrum Analysis , Structure-Activity Relationship , Zinc/chemistry , Zinc/metabolism
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 59(13): 3111-22, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14583286

ABSTRACT

X-band e.s.r. and optical absorption spectra of the imidazolate bridged heterobimetallic complexes [(tren)Cu-E-Im-Zn-(tren)](ClO(4))(3) and [(tren)Cu-E-Im-Ni-(tren)](ClO(4))(3), where trentris(2-aminoethyl)amine, E-Im=2-ethylimidazolate ion and the related mononuclear complexes [Cu(tren)](ClO(4))(2) and [(tren)Cu-E-ImH)](ClO(4))(2) have been described. Biological activities (superoxide dismutase and antimicrobial) have also been measured and compared with reported complexes.


Subject(s)
Anti-Infective Agents/chemistry , Imidazoles/analysis , Organometallic Compounds/analysis , Superoxide Dismutase , Anti-Infective Agents/pharmacology , Copper , Electron Spin Resonance Spectroscopy/methods , Enterococcus faecalis/drug effects , Escherichia coli/drug effects , Indicators and Reagents , Ligands , Microbial Sensitivity Tests , Models, Molecular , Nickel , Spectrophotometry , Zinc
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 59(4): 713-21, 2003 Mar 01.
Article in English | MEDLINE | ID: mdl-12609619

ABSTRACT

Magnetic, spectroscopic and superoxide dismutase activity of imidazolate bridged [(Salala)Cu-Im-Cu(Salala)]Na, [(Salala)Cu-Im-Zn(Salala)]Na and [(Salala)Cu-Im-Ni(Salala)]Na (Salala=Salicyledenealiniate, Im=Imdiazolate) are described. The epr and electronic spectra of related mononuclear complexes, viz., [(Salala)Cu-OH(2)] and [(Salala)Cu-ImH] also described. Appearance of a half-field signal in polycrystalline and decrease in mu(eff) per copper(II) ion indicate super exchange coupling between copper(II) ion in [(Salala)Cu-Im-Cu(Salala)]Na binuclear complex. A pH-dependent epr and UV-vis study of 50% aqueous DMSO solution of binuclear complexes suggest that the complexes are stable in narrow pH range.


Subject(s)
Copper/chemistry , Electron Spin Resonance Spectroscopy/methods , Imidazoles/chemistry , Magnetic Resonance Spectroscopy/methods , Nickel/chemistry , Superoxide Dismutase/chemistry , Zinc/chemistry , Copper/analysis , Hydrogen-Ion Concentration , Magnetics , Models, Chemical , Nickel/analysis , Spectrophotometry , Ultraviolet Rays , Zinc/analysis
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 58(13): 2961-9, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12477041

ABSTRACT

Bridged homobinuclear (copper-copper) and heterobinuclear (copper-zinc) complexes of diethylenetriamine have been prepared with 2-methyl-imidazole as bridging ligand. EPR spectra of the polycrystalline complexes have been studied at room temperature and also at liquid nitrogen temperature. Low temperature EPR and electronic spectroscopic studies of 50% aqueous DMSO of [(dien)Cu-(Melm)-Zn(dien)]3+ solutions show the imidazolate bridged complex to exist mainly over the pH range approximately 7.0 < pH < 10.0. At low pH the 2-MelmH+ ion and mononuclear copper and zinc complexes are formed. Above pH > 10.0 hydroxide ion splits the imidazolate bridge.


Subject(s)
Copper/chemistry , Imidazoles/chemistry , Polyamines/chemistry , Spectrum Analysis , Zinc/chemistry
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