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1.
Community Dent Health ; 33(4): 286-291, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28537366

RESUMEN

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.


Asunto(s)
Índice CPO , Niño , Caries Dental/epidemiología , Europa (Continente)/epidemiología , Femenino , Humanos , Masculino , Prevalencia , Sistema de Registros
2.
Foods ; 13(11)2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38890882

RESUMEN

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.

3.
Community Dent Health ; 30(3): 189-95, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24151795

RESUMEN

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.


Asunto(s)
Labio Leporino/psicología , Fisura del Paladar/psicología , Calidad de Vida , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Niño , Estudios Transversales , Recolección de Datos , Humanos , Almacenamiento y Recuperación de la Información , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
4.
Heliyon ; 8(5): e09373, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35592663

RESUMEN

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.

5.
Acta Crystallogr E Crystallogr Commun ; 78(Pt 2): 98-102, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35145731

RESUMEN

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.

7.
J Clin Invest ; 99(6): 1231-7, 1997 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-9077531

RESUMEN

Cartilage specimens from osteoarthritis (OA)-affected patients spontaneously released PGE2 at 48 h in ex vivo culture at levels at least 50-fold higher than in normal cartilage and 18-fold higher than in normal cartilage + cytokines + endotoxin. The superinduction of PGE2 production coincides with the upregulation of cyclooxygenase-2 (COX-2) in OA-affected cartilage. Production of both nitric oxide (NO) and PGE2 by OA cartilage explants is regulated at the level of transcription and translation. Dexamethasone inhibited only the spontaneously released PGE2 production, and not NO, in OA-affected cartilage. The NO synthase inhibitor HN(G)-monomethyl-L-arginine monoacetate inhibited OA cartilage NO production by > 90%, but augmented significantly (twofold) the spontaneous production of PGE2 in the same explants. Similarly, addition of exogenous NO donors to OA cartilage significantly inhibited PGE2 production. Cytokine + endotoxin stimulation of OA explants increased PGE2 production above the spontaneous release. Addition of L-NMMA further augmented cytokine-induced PGE2 production by at least fourfold. Inhibition of PGE2 by COX-2 inhibitors (dexamethasone or indomethacin) or addition of exogenous PGE2 did not significantly affect the spontaneous NO production. These data indicate that human OA-affected cartilage in ex vivo conditions shows (a) superinduction of PGE2 due to upregulation of COX-2, and (b) spontaneous release of NO that acts as an autacoid to attenuate the production of the COX-2 products such as PGE2. These studies, together with others, also suggest that PGE2 may be differentially regulated in normal and OA-affected chondrocytes.


Asunto(s)
Cartílago Articular/enzimología , Isoenzimas/biosíntesis , Óxido Nítrico/fisiología , Osteoartritis/enzimología , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Adulto , Anciano , Secuencia de Bases , Ciclooxigenasa 2 , Dinoprostona/antagonistas & inhibidores , Dinoprostona/biosíntesis , Dinoprostona/metabolismo , Inducción Enzimática/efectos de los fármacos , Humanos , Isoenzimas/genética , Proteínas de la Membrana , Persona de Mediana Edad , Datos de Secuencia Molecular , Óxido Nítrico/metabolismo , Prostaglandina-Endoperóxido Sintasas/genética , ARN Mensajero/biosíntesis
8.
Artículo en Inglés | MEDLINE | ID: mdl-16876473

RESUMEN

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.


Asunto(s)
Bacterias/efectos de los fármacos , Cobre/farmacología , Hongos/efectos de los fármacos , Compuestos Organometálicos/farmacología , Poliaminas/farmacología , Superóxido Dismutasa/metabolismo , Cobre/química , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Humanos , Magnetismo , Pruebas de Sensibilidad Microbiana , Poliaminas/química , Espectrofotometría Ultravioleta
9.
Artículo en Inglés | MEDLINE | ID: mdl-16307903

RESUMEN

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.


Asunto(s)
Antibacterianos/química , Antifúngicos/química , Cobre/química , Compuestos Organometálicos/química , Antibacterianos/síntesis química , Antibacterianos/farmacología , Antifúngicos/síntesis química , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Cristalografía por Rayos X , Hongos/efectos de los fármacos , Ligandos , Microscopía Electrónica , Estructura Molecular , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacología , Superóxido Dismutasa/química
10.
Biochim Biophys Acta ; 952(2): 220-9, 1988 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-2827779

RESUMEN

The hydroxylase component of methane monooxygenase (EC 1.14.13.25), which catalyzes the oxidation of methane to methanol, has been studied by visible, electron spin resonance and X-ray spectroscopies. The enzyme appears to possess a mu-oxo- or mu-hydroxo-bridged binuclear iron site, with no sulfur ligands to the cluster. Each Fe has 4-6 oxygen (or nitrogen) ligands, at an average distance of 1.92 +/- 0.03 A. The Fe-Fe distance is 3.05 +/- 0.05 A. Essentially all of the irons are in the Fe3+ state as the enzyme is prepared, but reduction with N-methylphenazonium methosulfate generates ESR-detectable states that appear to emanate from mixed-valence binuclear sites. One of these, with gav near 1.85, displays typical Curie law microwave saturation behavior, but the other, gav near 1.73, has a very potent method of spin-relaxation. Together they account for approximately 0.6 spins per molecule.


Asunto(s)
Euryarchaeota/enzimología , Oxigenasas de Función Mixta , Oxigenasas/metabolismo , Sitios de Unión , Espectroscopía de Resonancia por Spin del Electrón , Hierro/análisis , Cinética , Unión Proteica , Conformación Proteica , Espectrofotometría , Análisis Espectral , Termodinámica
11.
Curr Opin Biotechnol ; 12(6): 587-604, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11849941

RESUMEN

There has been an increasing awareness of the enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivity. Chiral intermediates and fine chemicals are in high demand, both from the pharmaceutical and agrochemical industries, for the preparation of bulk drug substances and agricultural products. Biocatalytic processes have been described for the synthesis of chiral intermediates for beta3- and beta2-receptor agonists, antihypertensive drugs, antiviral agents, melatonin receptor agonists, anticholesterol and anticancer drugs, and drugs to treat Alzheimer's disease.


Asunto(s)
Biotecnología/métodos , Industria Farmacéutica/métodos , Preparaciones Farmacéuticas/síntesis química , Agonistas de Receptores Adrenérgicos beta 2 , Agonistas de Receptores Adrenérgicos beta 3 , Anticolesterolemiantes/síntesis química , Antihipertensivos/síntesis química , Antineoplásicos/síntesis química , Antivirales/síntesis química , Catálisis , Inhibidores Enzimáticos/síntesis química , Humanos , Cinética , Modelos Químicos , Norleucina/síntesis química , Fenilalanina/química
12.
J Inorg Biochem ; 99(2): 651-63, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15621300

RESUMEN

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.


Asunto(s)
Cobre/química , Compuestos Organometálicos/química , Compuestos Organometálicos/síntesis química , Superóxido Dismutasa/química , Zinc/química , Animales , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Dominio Catalítico , Bovinos , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Técnicas In Vitro , Modelos Químicos , Estructura Molecular , Compuestos Organometálicos/farmacología , Espectrometría de Masa Bombardeada por Átomos Veloces , Espectrofotometría
13.
Artículo en Inglés | MEDLINE | ID: mdl-15866489

RESUMEN

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.


Asunto(s)
Antagonistas Adrenérgicos beta/aislamiento & purificación , Cromatografía Liquida/métodos , Cromatografía Liquida/instrumentación , Poliestirenos/química , Polivinilos/química , Reproducibilidad de los Resultados , Estereoisomerismo
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(1-2): 287-97, 2005 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-15556452

RESUMEN

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).


Asunto(s)
Cobre/química , Modelos Químicos , Compuestos Organometálicos/química , Superóxido Dismutasa/química , Absorción , Antibacterianos/farmacología , Carbono/química , Cristalografía por Rayos X , Electroquímica , Electrodos , Espectroscopía de Resonancia por Spin del Electrón , Vidrio , Concentración de Iones de Hidrógeno , Magnetismo , Conformación Molecular , Estructura Molecular , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacología , Soluciones , Superóxido Dismutasa/metabolismo
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(11-12): 2603-10, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16043054

RESUMEN

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.


Asunto(s)
Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/farmacología , Cobre/química , Compuestos Organometálicos/química , Zinc/química , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Materiales Biomiméticos/química , Color , Dimetilsulfóxido , Espectroscopía de Resonancia por Spin del Electrón , Concentración de Iones de Hidrógeno , Magnetismo , Estructura Molecular , Proteus vulgaris/efectos de los fármacos , Soluciones/química , Espectrofotometría , Superóxido Dismutasa/metabolismo , Superóxidos/química , Superóxidos/metabolismo
16.
Artículo en Inglés | MEDLINE | ID: mdl-15863062

RESUMEN

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.


Asunto(s)
Cobre/química , Espectroscopía de Resonancia por Spin del Electrón/métodos , Etilenodiaminas/química , Imidazoles/química , Compuestos Organometálicos/química , Superóxido Dismutasa/química , Sitios de Unión , Campos Electromagnéticos , Electrones , Concentración de Iones de Hidrógeno , Concentración 50 Inhibidora , Ligandos , Magnetismo , Modelos Químicos , Conformación Molecular , Espectrofotometría , Superóxidos/química , Temperatura
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 62(1-3): 261-8, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16257723

RESUMEN

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.


Asunto(s)
Cobre/química , Fenantrolinas/química , Poliaminas/química , Antibacterianos/farmacología , Cobre/farmacología , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Escherichia coli/efectos de los fármacos , Cinética , Ligandos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Conformación Molecular , Fenantrolinas/farmacología , Plásmidos/metabolismo , Poliaminas/farmacología , Proteus/efectos de los fármacos , Pseudomonas/efectos de los fármacos , Salmonella/efectos de los fármacos , Staphylococcus/efectos de los fármacos , Superóxido Dismutasa/metabolismo
18.
FEBS Lett ; 410(2-3): 259-64, 1997 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-9237641

RESUMEN

Chemically modified tetracyclines [CMT-3 (IC50 approximately 6-13 microM = approximately 2.5-5 microg/ml) and CMT-8 (IC50 approximately 26 microM = 10 microg/ml), but not CMT-1, -2 or -5], which lack anti-microbial activity, inhibited nitrite production in LPS-stimulated macrophages. Unlike competitive inhibitors of L-arginine which inhibited the specific activity of inducible nitric oxide synthase (iNOS) in cell-free extracts, CMTs exerted no such direct effect on the enzyme. CMTs could, however, be shown to inhibit both iNOS mRNA accumulation and protein expression in LPS-stimulated cells. Tetracyclines (doxycycline and CMT-3) unlike hydrocortisone had no significant effect on murine macrophages transfected with iNOS promoter (tagged to a luciferase reporter gene) in the presence of LPS. However, doxycycline and CMT-3 augmented iNOS mRNA degradation, in LPS-stimulated murine macrophages. These studies show a novel mechanism of action of tetracyclines which harbours properties to increase iNOS mRNA degradation and decrease iNOS protein expression and nitric oxide production in macrophages. This property of tetracyclines may have beneficial effects in the treatment of various diseases where excess nitric oxide has been implicated in the pathophysiology of these diseases.


Asunto(s)
Macrófagos/efectos de los fármacos , Óxido Nítrico Sintasa/genética , Procesamiento Postranscripcional del ARN/efectos de los fármacos , ARN Mensajero/metabolismo , Tetraciclinas/farmacología , Animales , Arginina/metabolismo , Citrulina/metabolismo , Doxiciclina/química , Doxiciclina/farmacología , Hidrocortisona/farmacología , Macrófagos/metabolismo , Ratones , Minociclina/química , Minociclina/farmacología , Estructura Molecular , Nitritos/metabolismo , ARN Mensajero/efectos de los fármacos , Tetraciclinas/química
19.
Biomol Eng ; 17(6): 167-82, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11337276

RESUMEN

Biocatalytic processes were used to prepare chiral intermediates required for the synthesis of Omapatrilat 1 by three different routes. The synthesis and enzymatic conversion of 2-keto-6-hydroxyhexanoic acid 3 to L-6-hydroxynorleucine 2 was demonstrated by reductive amination using beef liver glutamate dehydrogenase. To avoid the lengthy chemical synthesis of the ketoacid 3, a second route was developed to prepare the ketoacid by treatment of racemic 6-hydroxy norleucine [readily available from hydrolysis of 5-(4-hydroxybutyl) hydantoin 4] with D-amino acid oxidase from porcine kidney or Trigonopsis variabilis followed by reductive amination to convert the mixture completely to L-6-hydroxynorleucine in 98% yield and 99% enantiomeric excess (e.e.). The enzymatic synthesis of (S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (allysine ethylene acetal, 5) was demonstrated using phenylalanine dehydrogenase (PDH) from T. intermedius. Phenylalanine dehydrogenase was cloned and overexpressed in Escherichia coli and Pichia pastoris. Using PDH from E. coli or P. pastoris, the enzymatic process was scale-up to prepare kg quantity of allysine ethylene acetal 5. The reaction yields of >94% and e.e. of >98% were obtained for allysine ethylene acetal 5. An enzymatic process was developed for the synthesis of [4S-(4a,7a,10ab)]1-octahydro-5-oxo-4 [[(phenylmethoxy)carbonyl]amino]-7H-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid [BMS-199541-01]. The enzymatic oxidation of the epsilon-amino group of lysine in the dipeptide dimer N(2)-[N[[(phenyl-methoxy)carbonyl] L-homocysteinyl] L-lysine)-1,1-disulphide [BMS-201391-01] to produce BMS-199541-01 using a novel L-lysine epsilon-aminotransferase (LAT) from Sphingomonas paucimobilis SC 16113 was demonstrated. This enzyme was overexpressed in E. coli and a process was developed using the recombinant enzyme.


Asunto(s)
Antihipertensivos/síntesis química , Piridinas/síntesis química , Tiazepinas/síntesis química , Aminoácido Oxidorreductasas/química , Aminoácido Oxidorreductasas/metabolismo , Antihipertensivos/química , Antihipertensivos/metabolismo , Reactores Biológicos , D-Aminoácido Oxidasa/química , D-Aminoácido Oxidasa/metabolismo , Enzimas/química , Enzimas/farmacología , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentación , Glutamato Deshidrogenasa/química , Glutamato Deshidrogenasa/metabolismo , L-Lisina 6-Transaminasa , Pichia/genética , Pichia/metabolismo , Piridinas/química , Piridinas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Estereoisomerismo , Tiazepinas/química , Tiazepinas/metabolismo , Transaminasas/química , Transaminasas/metabolismo
20.
Adv Appl Microbiol ; 47: 33-78, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-12876794

RESUMEN

Biocatalytic processes were used to prepare chiral intermediates for pharmaceuticals. These include the following processes. Enzymatic synthesis of [4S-(4a,7a,10ab)]1-octahydro-5-oxo-4-[[(phenylmethoxy) carbonyl]amino]-7H-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid methyl ester (BMS-199541-01), a key chiral intermediate for synthesis of a new vasopeptidase inhibitor. Enzymatic oxidation of the epsilon-amino group of lysine in dipeptide dimer N2-[N[[(phenylmethoxy)carbonyl] L-homocysteinyl] L-lysine)1,1-disulfide (BMS-201391-01) to produce BMS-199541-01 using a novel L-lysine epsilon-aminotransferase from S. paucimobilis SC16113 was demonstrated. This enzyme was overexpressed in E. coli, and a process was developed using recombinant enzyme. The aminotransferase reaction required alpha-ketoglutarate as the amine acceptor. Glutamate formed during this reaction was recycled back to alpha-ketoglutarate by glutamate oxidase from S. noursei SC6007. Synthesis and enzymatic conversion of 2-keto-6-hydroxyhexanoic acid 5 to L-6-hydroxy norleucine 4 was demonstrated by reductive amination using beef liver glutamate dehydrogenase. To avoid the lengthy chemical synthesis of ketoacid 5, a second route was developed to prepare the ketoacid by treatment of racemic 6-hydroxy norleucine (readily available from hydrolysis of 5-(4-hydroxybutyl) hydantoin, 6) with D-amino acid oxidase from porcine kidney or T. variabilis followed by reductive amination to convert the mixture to L-6-hydroxynorleucine in 98% yield and 99% enantiomeric excess. Enzymatic synthesis of (S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (allysine ethylene acetal, 7), one of three building blocks used for synthesis of a vasopeptidase inhibitor, was demonstrated using phenylalanine dehydrogenase from T. intermedius. The reaction requires ammonia and NADH. NAD produced during the reaction was recycled to NADH by oxidation of formate to CO2 using formate dehydrogenase. Efficient synthesis of chiral intermediates required for total chemical synthesis of a beta 3 receptor agonist was demonstrated. These include: (a) microbial reduction of 4-benzyloxy-3-methanesulfonylamino-2'-bromoacetophenone 9 to corresponding (R)-alcohol 10 by S. paucimobilis SC16113, (b) enzymatic resolution of racemic alpha-methyl phenylalanine amide 11 and alpha-methyl-4-hydroxyphenylalanine amide 13 by amidase from M. neoaurum ATCC 25795 to prepare corresponding (S)-amino acids 12 and 14, and (c) asymmetric hydrolysis of methyl-(4-methoxyphenyl)-propanedioic acid ethyl diester 15 to corresponding (S)-monoester 16 by pig liver esterase. (S)[1-(acetoxyl)-4-(3-phenyl)butyl]phosphonic acid diethyl ester 21, a key chiral intermediate required for total chemical synthesis of BMS-188494 (an anticholesterol drug) was prepared by stereoselective acetylation of racemic [1-(hydroxy)-4-(3-phenyl)butyl]phosphonic acid diethyl ester 22 using G. candidum lipase. Lipase-catalyzed stereoselective acetylation of racemic 7-[N,N'-bis-(benzyloxy-carbonyl)N-(guanidinoheptanoyl)]-alpha-hydroxy-glycine 24 to corresponding S-(-)-acetate 25 was demonstrated. S-(-)-acetate 25 is a key intermediate for total chemical synthesis of (-)-15-deoxyspergualin 23, an immunosuppressive agent and antitumor antibiotic. Stereoselective microbial reduction of (1S)[3-chloro-2-oxo-1-(phenyl-methyl)propyl] carbamic acid, 1,1-dimethyl-ethyl ester 26 to corresponding chiral alcohol 27a (a key chiral intermediate for HIV protease inhibitors) was also demonstrated. Stereospecific enzymatic hydrolysis of racemic epoxide RS-1-[2',3'-dihydro benzo[b]furan-4'-yl]-1,2-oxirane 29 the corresponding R-diol 30 and unreacted chiral S-epoxide 28 was demonstrated using R. glutinis and A. niger. Dynamic resolution of racemic diol RS-1-[2',3'-dihydrobenzo[b]furan-4'-yl]-ethane-1,2-diol 32 to corresponding S-diol S-1-[2',3'-dihydrobenzo[b]furan-4'-yl]-ethane-1,2-diol 31 was demonstrated using C. boidinii and P. methanolica. Chiral (S)-epoxide 28 and (S)-diol 31 are key intermediates for a new prospective circadian modulator drug. Enzymatic resolution of racemic 2-pentanol and 2-heptanol by lipase B from Candida antarctica was demonstrated. S-(+)-2-pentanol is a key chiral intermediate required for synthesis of anti-Alzheimer's drugs.


Asunto(s)
Enzimas/química , Preparaciones Farmacéuticas/síntesis química , Agonistas Adrenérgicos beta/síntesis química , Agonistas Adrenérgicos beta/metabolismo , Anticolesterolemiantes/síntesis química , Anticolesterolemiantes/metabolismo , Antihipertensivos/síntesis química , Antihipertensivos/metabolismo , Antivirales/síntesis química , Antivirales/metabolismo , Catálisis , Enzimas/metabolismo , Fermentación , Guanidinas/síntesis química , Guanidinas/metabolismo , Preparaciones Farmacéuticas/metabolismo , Estereoisomerismo
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