A conversão eletrocatalítica de etanal em glioxal. Uma avaliação teórica

Introdução: uma proposta de modificação da síntese industrial de glioxal, o dial-deído mais simples, amplamente usado nas indústrias cosmética e farmacêutica, tem sido avaliada teoricamente. Trata-se, de fato, de uma adaptação de um método químico para a síntese eletroorgânica no ânodo, modificado por um revestimento polimèrico condutor, dopado pelo íon selenito. Metodologia: o modelo matemático correspondente tem sido desenvolvido e analisado mediante a teoria de estabilidade linear e análise de bifurcações. O conjunto de equações de balanço, para o modo potenciostático é bivariante. Resultados: foi provado que as capacitâncias da dupla camada elétrica (DCE) vêm sendo afetada tanto na etapa eletroquímica como na química. Essas influências são responsáveis pela aparição do comportamento osci-latório no sistema. Por outro lado, o estado estacionário se estabelece e se mantém facilmente, indicando um processo eletrocatalítico eficiente e com rendimento superior ao do processo químico. Conclusão: o elétrodo polimérico condutor, dopado pelo íon selenito é uma ferramenta eficiente para a conversão eletroorgânica do etanal em glioxal. Ao contrário do método clássico, este processo pode ser usado em escala industrial.

SUMMARY Introduction: A proposal for industrial synthesis for glyoxal, the simplest dialdehyde, widely used in cosmetics and pharmaceutical industry, has been theoretically evaluated. In fact, this is an adaptation of a chemical method for electroorganic synthesis over an anode, modified by a conducting polymer coating, doped by the selenite-ion. Methodology: A correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis. The balance equation-set for potentiostatic mode is bivariant. Results: It was proven that the double electric layer (DEL) capacitances are affected on both electrochemical and chemical stages. These influences are responsible for the appearance of the oscillatory behavior in the system. On the other hand, the steady-state becomes stable and maintains stable, indicating an efficient electroorganic method. The yield is expected to be higher than for the chemical system. Conclusion: The selenite-doped conducting polymer electrode is an efficient tool for ethanal electroorganic conversion into glyoxal. Contrarily to the classic method, it may be used in industrial scale.

Introducción: una propuesta de síntesis industrial de glioxal se ha evaluado teóricamente, este es el dialdehído más simple y es ampliamente utilizado en la industria cosmética y farmacéutica. De hecho, se trata de una adaptación de un método químico de síntesis electroorgánica sobre un ánodo, modificado por un recubrimiento de polímero conductor, dopado por el ion selenito. Metodología: se ha desarrollado y analizado un modelo matemático adecuado mediante la teoría de la estabilidad lineal y el análisis de bifurcaciones. El conjunto de ecuaciones de equilibrio para el modo potenciostático es bivariante. Resultados: se comprobó que las capacitancias de doble capa eléctrica (DEL) se ven afectadas tanto en las etapas electroquímicas como químicas. Estas influencias son las responsables de la aparición del comportamiento oscilatorio en el sistema. Por otro lado, el estado estacionario se vuelve estable y se mantiene estable, lo que indica un método electroorgá-nico eficiente. Se espera que el rendimiento sea mayor que para el sistema químico. Conclusión: el electrodo de polímero conductor dopado con selenita es una herramienta eficiente para la conversión electroorgánica de etanal en glioxal. A diferencia del método clásico, puede utilizarse a escala industrial.

Determination of formaldehyde and glyoxal in varenicline tartrate using derivative method with HPLC / 中国药科大学学报

@#To establish a method for the determination of formaldehyde and glyoxal simultaneously in varenicline tartrate active pharmaceutical ingredient (API) and its intermediate, formaldehyde and glyoxal were derivatized by 2, 4-dinitrophenylhydrazine (2,4-DNPH) to improve the HPLC retention and UV detection sensitivity. Separation was performed on a C8 (150 mm × 4.6 mm, 5 μm) column by linear gradient elution using acetonitrile and water as the mobile phase; the detective wavelength was set at 380 nm.Formaldehyde and glyoxal were quantitatively determined by an external reference method.Linear calibration was established for both formaldehyde and glyoxal in the range from 0.094 to 1.88 μg/mL.The detection and the quantification limits were 0.047 μg/mL (19 μg/g) and 0.094 μg/mL (38 μg/g), respectively.The recoveries were (95.0±1.1)% and (99.4 ± 2.6)% for formaldehyde and glyoxal, respectively.This method has been fully validated to be applicable to quantitative analysis of trace amount of formaldehyde and glyoxal in varenicline tartrate API and its intermediate.Test results demonstrated that the contents of both formaldehyde and glyoxal met the permitted daily exposure (PDE) limits for the finished products of varenicline tartrate API as well as its intermediate, though the glyoxal contents in the crude intermediates were likely to exceed the limit.The established method is valuable for the manufacturing process and quality control of varenicline tartrate.

Glyoxal modification mediates conformational alterations in silk fibroin: Induction of fibrillation with amyloidal features

Various animal models, especially rodents, are used to study pain, due to the difficulty of studying it inhumans. Many drugs that produce analgesia have been studied and there is evidence among whichNSAIDs deserve to be highlighted. Dexketoprofen (DEX) provides a broad antinociceptive profile indifferent types of pain; therefore, this study was designed to evaluate the profile of antinociceptivepotency in mice. Analgesic activity was evaluated using the acetic acid abdominal constriction test(writhing test), a chemical model of visceral pain. Dose-response curves for i.p. DEX administration (1,3, 10, 30 and 100 mg/kg), using at least six mice in each of at least five doses, was obtained before and30 min after pre-treatment with different pharmacological agents. Pretreatment of the mice with opioidreceptor antagonists was not effective; however, the serotonin receptor antagonist and nitric oxidesynthase inhibitor produce a significant increase in DEX-induced antinociception. The data from thepresent study shows that DEX produces antinociception in the chemical twisting test of mice, which isexplained with difficulty by the simple inhibition of COX. This effect appears to be mediated by othermechanisms in which the contribution of the NO and 5-HT pathways has an important effect on DEXinduced antinociception.

Expressions of ovarian function-related proteins in ovarian follicles in different development stages and their significances / 吉林大学学报(医学版)

Objective:To detect the expressions of ovarian function-related proteins in the ovarian follicles in different development stages,and to explore their roles and significances in the regulation of follicular development and ovarian function. Methods:The ovarian tissue containing primordial,primary,secondary follicles,mature follicles, atretic follicles and corpus albicans of the woman in the childbearing age was selected. Immunohisto chemical analysis was used to detect the expressions of Glyoxal enzyme I (glyoxalase I),ubiquitin carboxy-terminal hydrolase L1 (UCH-L1),heat shock protein 27 (HSP27),serum amyloid P (SAP)proteins in the ovarian follicles in different stages.The expression intensities of these proteins were compared.Results:The expression intensities of Glyoxalase I and UCH-L1 in the granulosa cells and theca cells of secondary follicles and marure follicles were strong,which were higher than those in the cytoplasm of primordial and primary follicles.The expression intensities of HSP27 in the cytoplasm of primordial and primary follicles were strong,which were higher than those in the granulosa cells and theca cells of secondary follicles and marure follicles.The expression intensities of Glyoxalase I and HSP27 in the atretic follicles were strong,which were higher than that in the growth follicles. The expressions of SAP were positive in the primordial,primary follicles,secondary and mature follicles and the expression intensities were not different.The expressions of four proteins in the corpus albicans did not express. Conclusion:The high expression of UCH-L1 and low expression of HSP27 are associated with the mature and development of follicles;the high expressions of Glyoxalase I and HSP27 are associated with the follicular atresia and ovarian failure.

Inhibitory effect of chlorogenic acid on senescence of human skin fibroblasts / 中华皮肤科杂志

[Abstract ] Objective To evaluate the inhibitory effect of chlorogenic acid on senescence of human skin fibroblasts (HSFs). Methods Fibroblasts isolated from human foreskin were treated with 1 mmol/L glyoxal in vitro to develop a model for cellular senescence. In order to select effective concentrations of chlorogenic acid, some HSFs were treated with 1 mmol/L glyoxal alone or in combination with chlorogenic acid at different concentrations (5, 10, 20, 40, 80 μmol/L)for 3 days, with those receiving no treatment serving as the blank control group. Then, methyl thiazolyl tetrazolium (MTT)assay was performed to evaluate the proliferative activity of HSFs. Some HSFs were divided into 5 groups to be cultured alone(blank control group), or treated with 1 mmol/L glyoxal(glyoxal group)or the combination of 1 mmol/L glyoxal and chlorogenic acid at effective concentrations of 10, 20 and 40 μmol/L (glyoxal + chlorogenic acid groups). Senescence associated β-galactosidase (SA-β-gal)staining and real-time fluorescence-based quantitative PCR were conducted to determine the percentage of senescent cells and expression level of p16INK4a mRNA respectively. Statistical analysis was carried out by one-way analysis of variance followed by the least significant difference(LSD)-t test. Results Compared with the blank control group, the glyoxal group showed significantly decreased cellular proliferative activity of HSFs (55.65% ± 2.00% vs. 100% ± 6.90%, P 0.05). Therefore, 10 - 40 μmol/L was selected as the effective concentrations of chlorogenic acid. The glyoxal group showed significant increases in the percentage of senescent (SA-β-gal-positive)cells (35.65% ± 2.24% vs. 13.00% ± 2.22%, P < 0.01)and expression level of p16INK4a mRNA (2-ΔΔCt: 1.00 ± 0.06 vs. 0.26 ± 0.05, P <0.01)compared with the blank control group, while the glyoxal + 10-, 20-, 40-μmol/L chlorogenic acid groups showed significantly decreased percentage of senescent cells (31.50% ± 2.13% , 22.31% ± 3.11% and 19.32% ± 3.01%respectively)and expression level of p16INK4a mRNA (2-ΔΔCt: 0.88 ± 0.08, 0.73 ± 0.06 and 0.68 ± 0.04 respectively) compared with the glyoxal group (all P < 0.05). Additionally, the percentage of senescent cells decreased with the increase in chlorogenic acid concentrations in the glyoxal + chlorogenic acid groups. Conclusion Chlorogenic acid can protect HSFs from glyoxal-induced senescence.

Heterologous Expression of Phanerochaete chrysoporium Glyoxal Oxidase and its Application for the Coupled Reaction with Manganese Peroxidase to Decolorize Malachite Green

cDNA of the glx1 gene encoding glyoxal oxidase (GLX) from Phanerochaete chrysosporium was isolated and expressed in Pichia pastoris. The recombinant GLX (rGLX) produces H2O2 over 7.0 nmol/min/mL using methyl glyoxal as a substrate. Use of rGLX as a generator of H2O2 improved the coupled reaction with recombinant manganese peroxidase resulting in decolorization of malachite green up to 150 microM within 90 min.