Glutathione in the Brain

Glutathione (GSH) is the most abundant non-protein thiol, and plays crucial roles in the antioxidant defense system and the maintenance of redox homeostasis in neurons. GSH depletion in the brain is a common finding in patients with neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, and can cause neurodegeneration prior to disease onset. Excitatory amino acid carrier 1 (EAAC1), a sodium-dependent glutamate/cysteine transporter that is selectively present in neurons, plays a central role in the regulation of neuronal GSH production. The expression of EAAC1 is posttranslationally controlled by the glutamate transporter-associated protein 3–18 (GTRAP3-18) or miR-96-5p in neurons. The regulatory mechanism of neuronal GSH production mediated by EAAC1 may be a new target in therapeutic strategies for these neurodegenerative diseases. This review describes the regulatory mechanism of neuronal GSH production and its potential therapeutic application in the treatment of neurodegenerative diseases.     

STABILITY AND SENSORY QUALITY OF SPRAY DRIED AVOCADO PASTE

Avocado (Persea americand) paste was spray dried at inlet air temperature of 180°C, 80°C outlet air temperature, air velocity of 27 m/s and a feed flow rate of 0.642 l/min. Lipids in the paste were emulsified using 10 % Monoacylglyceride (MAG). Treatments were applied according to the following antioxidants mixtures: 1) BHA (butylated hydroxyanisole) + BHT (butylated hydroxytoluene) (0.05 % each); 2) TBHQ (Tertiary butylated hydroxyquinone) + Citric Acid (0.05 + 0.1 %); 3) BHA + BHT + Citric Acid (0.05 + 0.05 + 0.1 %); 4) BHA + Propyl gallate (0.05 + 0.05 %); or 5) BHA + Propyl gallate + Citric acid (0.05 + 0.05 + 0.1 %). Samples were stored at 6, 12, 25, 28 and 40 °C. Peroxide values were determined periodically. Development of rancidity was detected by sensory evaluation of the samples. For samples kept at 6 and 12 °C, an antioxidant mixture containing BHA and propyl gallate at 0.05% gave the least protection to the stored avocado powder. The mixture containing TBHQ and citric acid yielded the lowest rancidity development.     

STABILITY AND SENSORY QUALITY OF SPRAY DRIED AVOCADO PASTE

ABSTRACT

Avocado (Persea americand) paste was spray dried at inlet air temperature of 180°C, 80°C outlet air temperature, air velocity of 27 m/s and a feed flow rate of 0.642 l/min. Lipids in the paste were emulsified using 10 % Monoacylglyceride (MAG). Treatments were applied according to the following antioxidants mixtures: 1) BHA (butylated hydroxyanisole) + BHT (butylated hydroxytoluene) (0.05 % each); 2) TBHQ (Tertiary butylated hydroxyquinone) + Citric Acid (0.05 + 0.1 %); 3) BHA + BHT + Citric Acid (0.05 + 0.05 + 0.1 %); 4) BHA + Propyl gallate (0.05 + 0.05 %); or 5) BHA + Propyl gallate + Citric acid (0.05 + 0.05 + 0.1 %). Samples were stored at 6, 12, 25, 28 and 40 °C. Peroxide values were determined periodically. Development of rancidity was detected by sensory evaluation of the samples. For samples kept at 6 and 12 °C, an antioxidant mixture containing BHA and propyl gallate at 0.05% gave the least protection to the stored avocado powder. The mixture containing TBHQ and citric acid yielded the lowest rancidity development.     

Modulating the ERK1/2–MMP1 Axis through Corosolic Acid Inhibits Metastasis of Human Oral Squamous Cell Carcinoma Cells

Corosolic acid (CA; 2α-hydroxyursolic acid) is a natural pentacyclic triterpenoid with antioxidant, antitumour and antimetastatic activities against various tumour cells during tumourigenesis. However, CA’s antitumour effect and functional roles on human oral squamous cell carcinoma (OSCC) cells are utterly unknown. In this study, our results demonstrated that CA significantly exerted an inhibitory effect on matrix metalloproteinase (MMP)1 expression, cell migration and invasion without influencing cell growth or the cell cycle of human OSCC cells. The critical role of MMP1 was confirmed using the GEPIA database and showed that patients have a high expression of MMP1 and have a shorter overall survival rate, confirmed on the Kaplan–Meier curve assay. In the synergistic inhibitory analysis, CA and siMMP1 co-treatment showed a synergically inhibitory influence on MMP1 expression and invasion of human OSCC cells. The ERK1/2 pathway plays an essential role in mediating tumour progression. We found that CA significantly inhibits the phosphorylation of ERK1/2 dose-dependently. The ERK1/2 pathway played an essential role in the CA-mediated downregulation of MMP1 expression and in invasive motility in human OSCC cells. These findings first demonstrated the inhibitory effects of CA on OSCC cells’ progression through inhibition of the ERK1/2–MMP1 axis. Therefore, CA might represent a novel strategy for treating OSCC.     

ANT1 Activation and Inhibition Patterns Support the Fatty Acid Cycling Mechanism for Proton Transport

Adenine nucleotide translocase (ANT) is a well-known mitochondrial exchanger of ATP against ADP. In contrast, few studies have shown that ANT also mediates proton transport across the inner mitochondrial membrane. The results of these studies are controversial and lead to different hypotheses about molecular transport mechanisms. We hypothesized that the H⁺-transport mediated by ANT and uncoupling proteins (UCP) has a similar regulation pattern and can be explained by the fatty acid cycling concept. The reconstitution of purified recombinant ANT1 in the planar lipid bilayers allowed us to measure the membrane current after the direct application of transmembrane potential ΔΨ, which would correspond to the mitochondrial states III and IV. Experimental results reveal that ANT1 does not contribute to a basal proton leak. Instead, it mediates H⁺ transport only in the presence of long-chain fatty acids (FA), as already known for UCPs. It depends on FA chain length and saturation, implying that FA’s transport is confined to the lipid-protein interface. Purine nucleotides with the preference for ATP and ADP inhibited H⁺ transport. Specific inhibitors of ATP/ADP transport, carboxyatractyloside or bongkrekic acid, also decreased proton transport. The H⁺ turnover number was calculated based on ANT1 concentration determined by fluorescence correlation spectroscopy and is equal to 14.6 ± 2.5 s⁻¹. Molecular dynamic simulations revealed a large positively charged area at the protein/lipid interface that might facilitate FA anion’s transport across the membrane. ANT’s dual function—ADP/ATP and H⁺ transport in the presence of FA—may be important for the regulation of mitochondrial membrane potential and thus for potential-dependent processes in mitochondria. Moreover, the expansion of proton-transport modulating drug targets to ANT1 may improve the therapy of obesity, cancer, steatosis, cardiovascular and neurodegenerative diseases.     

硫酸两转两吸干吸工序的自动串酸模型

针对硫酸两转两吸生产中第一、二吸收酸循环槽不共槽情况下,对二吸系统是采用加水还是串酸以配置98%H2SO4进行了分析计算,并根据<硫酸干吸工序串酸自控方案的可行性分析与优化>研究结论在已有方案中补上该处合理的自控方式,形成一套完整的干吸工序自动串酸模型.     

Influence of acid dyes on the thermal behavior of nylon 66

To reveal the effect of acid dyes on the melt processing of recycled nylon 66, 17 acid dyes with different chemical structures were used to dye a nylon 66 yarn. The thermal stability of dyestuffs, the thermal degradation of the dyed nylon 66 during compression molding, and the melting and crystallization of the dyed nylon were investigated. During melt processing, most dyed nylon 66 changed color strength and color pattern. This is attributed to the migration and chemical reactions of dyestuffs. Acid dyes containing metal ions, such as C.I. Acid Black 60, C.I. Acid Red 186, C.I. Acid Yellow 151, and C.I. Acid Black 107, have severe impact on the thermal stability of nylon 66. The influence of metal complex acid dyes on the thermal stability of nylon 66 can be explained by a mechanism of acid-catalyzed nucleophilic acyl substitution. It was observed that the existence of acid dye in nylon 66 does not influence the melting temperature of nylon. However, some metal complex dyes reduce the crystallization temperature of molten nylon. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 371–382, 1998     

Phytochemical Molecules from the Decarboxylation of Gomphrenins in Violet Gomphrena globosa L.—Floral Infusions from Functional Food

Herein, the generation of decarboxylated derivatives of gomphrenin pigments exhibiting potential health-promoting properties and the kinetics of their extraction during tea brewing from the purple flowers of Gomphrena globosa L. in aqueous and aqueous citric acid solutions were investigated. Time-dependent concentration monitoring of natural gomphrenins and their tentative identification was carried out by LC-DAD-ESI-MS/MS. The high content of acylated gomphrenins and their principal decarboxylation products, 2-, 15-, 17-decarboxy-gomphrenins, along with minor levels of their bidecarboxylated derivatives, were reported in the infusions. The identification was supported by the determination of molecular formulas of the extracted pigments by liquid chromatography coupled with high-resolution mass spectrometry (LCMS-IT-TOF). The influence of plant matrix on gomphrenins’ stability and generation of their derivatives, including the extraction kinetics, was determined by studying the concentration profiles in the primary and diluted infusions. Isolated and purified acylated gomphrenins from the same plant material were used for the preliminary determination of their decarboxylated derivatives. The acylated gomphrenins were found to be more stable than nonacylated ones. Citric acid addition had a degradative influence on natural gomphrenins mainly during the longer tea brewing process (above 15 min); however, the presence of plant matrix significantly increased the stability for betacyanins’ identification.     

Blood Plasma’s Protective Ability against the Degradation of S-Nitrosoglutathione under the Influence of Air-Pollution-Derived Metal Ions in Patients with Exacerbation of Heart Failure and Coronary Artery Disease

One of the consequences of long-term exposure to air pollutants is increased mortality and deterioration of life parameters, especially among people diagnosed with cardiovascular diseases (CVD) or impaired respiratory system. Aqueous soluble inorganic components of airborne particulate matter containing redox-active transition metal ions affect the stability of S-nitrosothiols and disrupt the balance in the homeostasis of nitric oxide. Blood plasma’s protective ability against the decomposition of S-nitrosoglutathione (GSNO) under the influence of aqueous PM extract among patients with exacerbation of heart failure and coronary artery disease was studied and compared with a group of healthy volunteers. In the environment of CVD patients’ plasma, NO release from GSNO was facilitated compared to the plasma of healthy controls, and the addition of ascorbic acid boosted this process. Model studies with albumin revealed that the amount of free thiol groups is one of the crucial factors in GSNO decomposition. The correlation between the concentration of NO released and -SH level in blood plasma supports this conclusion. Complementary studies on gamma-glutamyltranspeptidase activity and ICP-MS multielement analysis of CVD patients’ plasma samples in comparison to a healthy control group provide broader insights into the mechanism of cardiovascular risk development induced by air pollution.     

柠檬酸二乙酯选择性降低烟气烟碱

通过在卷烟滤嘴中添加柠檬酸二乙酯,在不改变烟支物理状态的条件下,能够有选择性降低主流烟气的烟碱,而基本不改变焦油等其他烟气常规成分。同时卷烟感官评价结果表明添加柠檬酸二乙酯对卷烟烟气劲头、刺激、细腻程度、干燥感、杂气等都有一定的改善作用。     

GABA: A Key Player in Drought Stress Resistance in Plants

γ-aminobutyric acid (GABA) is a non-protein amino acid involved in various physiological processes; it aids in the protection of plants against abiotic stresses, such as drought, heavy metals, and salinity. GABA tends to have a protective effect against drought stress in plants by increasing osmolytes and leaf turgor and reducing oxidative damage via antioxidant regulation. Guard cell GABA production is essential, as it may provide the benefits of reducing stomatal opening and transpiration and controlling the release of tonoplast-localized anion transporter, thus resulting in increased water-use efficiency and drought tolerance. We summarized a number of scientific reports on the role and mechanism of GABA-induced drought tolerance in plants. We also discussed existing insights regarding GABA’s metabolic and signaling functions used to increase plant tolerance to drought stress.     

Novel Insights into Selected Disease-Causing Mutations within the SLC35A1 Gene Encoding the CMP-Sialic Acid Transporter

Congenital disorders of glycosylation (CDG) are a group of rare genetic and metabolic diseases caused by alterations in glycosylation pathways. Five patients bearing CDG-causing mutations in the SLC35A1 gene encoding the CMP-sialic acid transporter (CST) have been reported to date. In this study we examined how specific mutations in the SLC35A1 gene affect the protein’s properties in two previously described SLC35A1-CDG cases: one caused by a substitution (Q101H) and another involving a compound heterozygous mutation (T156R/E196K). The effects of single mutations and the combination of T156R and E196K mutations on the CST’s functionality was examined separately in CST-deficient HEK293T cells. As shown by microscopic studies, none of the CDG-causing mutations affected the protein’s proper localization in the Golgi apparatus. Cellular glycophenotypes were characterized using lectins, structural assignment of N- and O-glycans and analysis of glycolipids. Single Q101H, T156R and E196K mutants were able to partially restore sialylation in CST-deficient cells, and the deleterious effect of a single T156R or E196K mutation on the CST functionality was strongly enhanced upon their combination. We also revealed differences in the ability of CST variants to form dimers. The results of this study improve our understanding of the molecular background of SLC35A1-CDG cases.     

柠檬酸硬脂酸季戊四醇三元共聚蜡状物的研制

以柠檬酸、季戊四醇、硬脂酸为原料,采用直接酯化的两步反应合成了柠檬酸硬脂酸季戊四醇酯蜡,并对反应条件进行了优化。固定季戊四醇为0.1 mol的最佳条件为：第一步反应温度为200℃,时间1 h,硬脂酸用量28 g,催化剂为总质量的0.4%;第二步柠檬酸用量为10 g,反应温度150℃,反应时间3 h。最终产物为蜡状物质,酸值为2.2 mgKOH/g,针入度为0.1 mm,滴熔点为70℃。     

Recent Advances in Biological Activity,New Formulations and Prodrugs of Ferulic Acid

Trans-ferulic acid (FA) is a derivative of 4-hydroxycinnamic acid, which is found in many food products, fruits and beverages. It has scientifically proven antioxidant, anti-inflammatory and antibacterial properties. However, its low ability to permeate through biological barriers (e.g., the blood–brain barrier, BBB), its low bioavailability and its fast elimination from the gastrointestinal tract after oral administration limit its clinical use, e.g., for the treatment of neurodegenerative diseases, such as Alzheimer’s disease. Therefore, new nanotechnological approaches are developed in order to regulate intracellular transport of ferulic acid. The objective of this review is to summarize the last decade’s research on biological properties of ferulic acid and innovative ways of its delivery, supporting pharmacological therapy.     

Mechanisms of Colorectal Cancer Prevention by Aspirin—A Literature Review and Perspective on the Role of COX-Dependent and -Independent Pathways

Aspirin, synthesized and marketed in 1897 by Bayer, is one of the most widely used drugs in the world. It has a well-recognized role in decreasing inflammation, pain and fever, and in the prevention of thrombotic cardiovascular diseases. Its anti-inflammatory and cardio-protective actions have been well studied and occur through inhibition of cyclooxygenases (COX). Interestingly, a vast amount of epidemiological, preclinical and clinical studies have revealed aspirin as a promising chemopreventive agent, particularly against colorectal cancers (CRC); however, the primary mechanism by which it decreases the occurrences of CRC has still not been established. Numerous mechanisms have been proposed for aspirin’s chemopreventive properties among which the inhibition of COX enzymes has been widely discussed. Despite the wide attention COX-inhibition has received as the most probable mechanism of cancer prevention by aspirin, it is clear that aspirin targets many other proteins and pathways, suggesting that these extra-COX targets may also be equally important in preventing CRC. In this review, we discuss the COX-dependent and -independent pathways described in literature for aspirin’s anti-cancer effects and highlight the strengths and limitations of the proposed mechanisms. Additionally, we emphasize the potential role of the metabolites of aspirin and salicylic acid (generated in the gut through microbial biotransformation) in contributing to aspirin’s chemopreventive actions. We suggest that the preferential chemopreventive effect of aspirin against CRC may be related to direct exposure of aspirin/salicylic acid or its metabolites to the colorectal tissues. Future investigations should shed light on the role of aspirin, its metabolites and the role of the gut microbiota in cancer prevention against CRC.     

Die Stabilisierung von Sojaöl durch Behandlung mit Zitronensäure - Zur Erinnerung an Julius D. Taussky -

Stabilizing of Soya Bean Oil by Citric Acid Treatment - In Memory of Julius D. Taussky When in the beginning of the twenties of this century large quantities of soya beans were processed for the first time, the production of keepable soya bean oils caused great difficulties. In this situation the proposal of Julius D. Taussky to add small amounts of citric acid to the neutralized and bleached oil in the beginning of deodorisation turned out to be a very effective agent in the production of oils stable in taste. The submitted report deals the historical development of the Taussky-process, whose importance for raffination of edible oils is up to now unrestricted.     

Regioselective carboxylation of aromatic compounds using cyclodextrin as mediator

The direct introduction of a carboxylic group into an aromatic carboxylic acid has been considered difficult theoretically. Recently, the regioselective syntheses of terephthalic acid, 4,4′-biphenyldicarboxylic acid and 2,6-naphthalene-dicarboxylic acid have been achieved by the carboxylation of benzoic acid, 4-biphenylcarboxylic acid and 2-naphthalenecarboxylic acid, respectively, with carbon tetrachloride and copper powder in aqueous alkali, using β-cyclodextrin (β-CyD) as mediator under mild conditions. The one-pot syntheses of terephthalic acid, 4,4′-biphenyldicarboxylic acid and 2,6-naphthalene-dicarboxylic acid have been attained by the carboxylation of benzene, biphenyl and naphthalene, respectively, with carbon tetrachloride and copper powder in aqueous alkali, using β-CyD as mediator. The essential factor of the carboxylation by the use of β-CyD is the inclusion complex formations of β-CyD with aromatic hydrocarbon, β-CyD with aromatic monocarboxylate and β-CyD with carbon tetrachloride, respectively, in the reaction mixture. The conformations of CyD–aromatic monocarboxylate inclusion complexes in aqueous alkali have been determined by the nuclear magnetic resonance spectroscopy using ¹H homonuclear Overhauser enhancement on the rotating frame. The high selectivity is ascribed to the conformation of the β-CyD–aromatic monocarboxylate inclusion complex. The reaction mechanism is discussed on the basis of inclusion complex formation.     

二相厌氧-好氧处理柠檬酸废水工程设计

采用气浮-二相厌氧-延时曝气为主体的处理工艺，结合清水回流稀释，处理柠檬酸废水，废水处理规模为1000m^3/d，进水中COD为1 2000mg/L，BOD5为3000mg/L，SS为3500mg/L，出水达到GB8978-1996一级排放标准，工程投资和运行费用较低.