Tehnološki aspekti transseterifikacije biljnih ulja etanolom u prisutnosti metalnih oksida

Transesterification of vegetable oil with ethanol in the presence of fine metal oxide particles as catalysts has been investigated. Zinc and nickel(II) oxides were shown to have the highest catalytic activity. In their presence, the conversion of sunflower oil triglycerides, after 150 min, reached 95.3 and 94.2 %, respectively. The optimal mass fraction of zinc oxide catalyst was found to be 0.25–0.31 %. In the presence of zinc oxide, with mass fraction of water in ethanol of 5 and 10 %, the conversion of triglycerides was 98.5 and 94.8 %, respectively. This work is licensed under a Creative Commons Attribution 4.0 International License.Ispitana je transseterifikacija biljnog ulja etanolom u prisustvu sitnih čestica metalnih oksida kao katalizatora. Pokazalo se da najveću katalitičku aktivnost imaju cinkovi i nikl(II) oksidi. U njihovoj prisutnosti, konverzija triglicerida suncokretova ulja nakon 150 min dostigla je 95,3 odnosno 94,2 %. Otkriveno je da je optimalni maseni udio katalizatora cinkova oksida 0,25 – 0,31 %. U prisutnosti cinkova oksida, s udjelom vode u etanolu od 5 i 10 mas.%, konverzija triglicerida iznosila je 98,5 odnosno 94,8 %. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Дослідження естерифікації суміші нижчих дикарбонових кислот 2-етилгексан-1-олом у присутності п-толуенсульфонової кислоти

Regularities of esterification of the mixture of lower dicarboxylic acids (succinic, glutaric, adipic) by 2-ethylhexan-1-ol in the presence of catalysts – p-toluensulfonic and sulfuric acids under non-stationary conditions were studied. It was found that in the presence of mineral acid, the reaction flows at a lower rate. Application of benzene as a substance that facilitates separation of water, formed in the esterification reaction, makes it possible, due to a lower reaction temperature, to decrease energy consumption of the process at an increase in conversion of dicarboxylic acids from 95.8 to 99.5 %. It was shown that the use of activated carbon of different brands simultaneously with catalysis by p-toluensulfonic acid with virtually the same effectiveness can decrease chromaticity intensity of esterification products by more than three times. The use of finely dispersed activated carbon 208CP and DCL 200 compared with coarse-grained activated carbon BAU-A additionally provides higher intensity of esterification reaction due to improvement of removal of water from the reaction mixture. It was found that an increase in the content of activated carbon DLC 200 by more than 0.3 % by weight in the reaction mixture contributes to a sharp decrease in the process intensity. This influence is explained by neutralization of a part of the catalysts by alkaline components of activated carbon, which decreases its active concentration and inhibits the reaction. Optimum conditions of the esterification process were proposed. The authors determined dependences of density and kinematic viscosity of the mixture of diesters of succinic, glutaric and adipic acids, and 2-ethylhexan-1-ol, separated from the esterification reaction products, on temperature and described them with regression equationsИсследована этерификация низших дикарбоновых кислот 2-этилгексан-1-олом, катализируемая п-толуолсульфоновой кислотой. Определено влияние бензола, катализатора, активированного угля на продолжительность реакции, конверсию карбоксильных групп реагентов и интенсивность окраски реакционной смеси. Установлены оптимальные условия процесса получения смеси диэфиров янтарной, глутаровой, адипиновой кислот и определены состав и физические свойства этой смесиДосліджено естерифікацію нижчих дикарбонових кислот 2-етилгексан-1-олом, каталізовану п-толуенсульфоновою кислотою. Визначено вплив бензену, каталізатора, активованого вугілля на тривалість реакції, конверсію карбоксильних груп реагентів та інтенсивність забарвлення реакційної суміші. Встановлено оптимальні умови процесу одержання суміші діестерів бурштинової, глутарової, адипінової кислот і визначено склад та фізичні властивості цієї суміш

Дослідження трансестерифікації тригліцеридів аліфатичними спиртами С2–С4 у присутності іонітів

We studied the reaction of transesterification of triglycerides of sunflower oil by aliphatic alcohols С2–С4 in the presence of the cationite CU-2-8 in H-form and with the immobilized ions of metals and the anionite AV-17-8. We investigated the influence of the type of ionite, immobilized cation of metal, the structure of alcohol, molar ratio of triglyceride:alcohol, temperature, and the content of catalyst in the reaction mixture on the rate of reaction of transesterification and conversion of triglycerides. It was established that the activity of catalysts, based on the cationite CU-2-8 with immobilized ions of metals, in the reaction of transesterification of triglycerides by alcohols С2–С4 depends on the type of the immobilized ion of metal. It was shown that the cationite CU-2-8 with immobilized ions of Ni2+, Sn2+, Co2 and in H-form demonstrates the highest activity in the reaction of transesterification. It was established that in the presence of the examined catalysts conversion of triglycerides decreases with an increase in the length of the alcohol chain. Extreme dependence of the rate of transesterification reaction and conversion of triglycerides on the content of the catalyst–ionite was established. Optimum conditions for the reaction of transesterification of triglyceride by aliphatic alcohols С2–С4 were found. It was established that optimal content of catalyst is 2 % by weight; molar ratio of alcohol:TG for ethanol, propane-1-ol and propane-2-ol is (4‒5):1, for butane-1-ol, it is 10:1.The temperature of reaction should be close to the boiling temperature of alcohol. It was shown that the examined catalysts demonstrate high activity in the reaction of transesterification of triglycerides and make it possible to achieve high conversion rate of starting materials. The results obtained indicate the feasibility of applying catalysts based on the cationite CU-2-8 with immobilized ions of metals in the reaction of transesterification of triglycerides by alcohols С2–С4.Исследована переэтерификация триглицеридов подсолнечного масла алифатическими спиртами С2–С4 в присутствии катионита КУ-2-8 в Н-форме и с иммобилизованными ионами металлов и анионита АВ-17-8. Определено влияние строения спирта, вида ионита, иммобилизованного катиона металла, мольного соотношения реагентов, температуры реакции, содержания катализатора в реакционной смеси на скорость реакции переэтерификации и конверсию триглицеридовДосліджено трансестерифікацію тригліцеридів соняшникової олії аліфатичними спиртами С2–С4 у присутності катіоніту КУ-2-8 у Н-формі та з іммобілізованими іонами металів і аніоніту АВ-17-8. Визначено вплив будови спирту, виду іоніту, іммобілізованого катіону металу, мольного співвідношення реагентів, температури реакції, вмісту каталізатора у реакційній суміші на швидкість реакції трансестерифікації та конверсію тригліцериді

Effectiveness of Methylcobalamin and Folinic Acid Treatment on Adaptive Behavior in Children with Autistic Disorder Is Related to Glutathione Redox Status

Treatments targeting metabolic abnormalities in children with autism are limited. Previously we reported that a nutritional treatment significantly improved glutathione metabolism in children with autistic disorder. In this study we evaluated changes in adaptive behaviors in this cohort and determined whether such changes are related to changes in glutathione metabolism. Thirty-seven children diagnosed with autistic disorder and abnormal glutathione and methylation metabolism were treated with twice weekly 75 µg/Kg methylcobalamin and twice daily 400 µg folinic acid for 3 months in an open-label fashion. The Vineland Adaptive Behavior Scale (VABS) and glutathione redox metabolites were measured at baseline and at the end of the treatment period. Over the treatment period, all VABS subscales significantly improved with an average effect size of 0.59, and an average improvement in skills of 7.7 months. A greater improvement in glutathione redox status was associated with a greater improvement in expressive communication, personal and domestic daily living skills, and interpersonal, play-leisure, and coping social skills. Age, gender, and history of regression did not influence treatment response. The significant behavioral improvements observed and the relationship between these improvements to glutathione redox status suggest that nutritional interventions targeting redox metabolism may benefit some children with autism

Examining associations between prenatal biomarkers of oxidative stress and ASD-related outcomes using quantile regression.

We examined associations between prenatal oxidative stress (OS) and child autism-related outcomes. Women with an autistic child were followed through a subsequent pregnancy and that younger siblings childhood. Associations between glutathione (GSH), glutathione disulfide (GSSG), 8-oxo-deoxyguanine (8-OHdG), and nitrotyrosine and younger sibling Social Responsiveness Scale (SRS) scores were examined using quantile regression. Increasing GSH:GSSG (suggesting decreasing OS) was associated with minor increases in SRS scores (50th percentile β: 1.78, 95% CI: 0.67, 3.06); no other associations were observed. Results from this cohort with increased risk for autism do not support a strong relationship between OS in late pregnancy and autism-related outcomes. Results may be specific to those with enriched autism risk; future work should consider other timepoints and biomarkers

Mechanisms of peroxisome proliferator-induced DNA hypomethylation in rat liver☆

Genomic hypomethylation is a consistent finding in both human and animal tumors and mounting experimental evidence suggests a key role for epigenetic events in tumorigenesis. Furthermore, it has been suggested that early changes in DNA methylation and histone modifications may serve as sensitive predictive markers in animal testing for carcinogenic potency of environmental agents. Alterations in metabolism of methyl donors, disturbances in activity and/or expression of DNA methyltransferases, and presence of DNA single-strand breaks could contribute to the loss of cytosine methylation during carcinogenesis; however, the precise mechanisms of genomic hypomethylation induced by chemical carcinogens remain largely unknown. This study examined the mechanism of DNA hypomethylation during hepatocarcinogenesis induced by peroxisome proliferators WY-14,643 (4-chloro-6-(2,3-xylidino)-pyrimidynylthioacetic acid) and DEHP (di-(2-ethylhexyl)phthalate), agents acting through non-genotoxic mode of action. In the liver of male Fisher 344 rats exposed to WY-14,643 (0.1% (w/w), 5 months), the level of genomic hypomethylation increased by ~2-fold, as compared to age-matched controls, while in the DEHP group (1.2% (w/w), 5 months) DNA methylation did not change. Global DNA hypomethylation in livers from WY-14,643 group was accompanied by the accumulation of DNA single-strand breaks, increased cell proliferation, and diminished expression of DNA methyltransferase 1, while the metabolism of methyl donors was not affected. In contrast, none of these parameters changed significantly in rats fed DEHP. Since WY-14,643 is much more potent carcinogen than DEHP, we conclude that the extent of loss of DNA methylation may be related to the carcinogenic potential of the chemical agent, and that accumulation of DNA single-strand breaks coupled to the increase in cell proliferation and altered DNA methyltransferase expression may explain genomic hypomethylation during peroxisome proliferator-induced carcinogenesis

The aggregatibacter actinomycetemcomitans heat shock protein GroEL interacts directly with human peripheral blood T cells

Heat shock family protein GroEL of Aggregatibacter actinomycetemcomitans (Aa) has antigenic properties. We previously demonstrated that A. actinomycetemcomitans GroEL-like protein affects human CD4 T cells by converting them into IL-10 and IFNg double cytokine producing Tbet+ Th1 cells. The objective of this study was to investigate whether or not AaGroEL communicates with T cells directly. To do this, sorted cells from peripheral blood mononuclear cells were stimulated with AaGroEL for 48 h. Flow cytometry was used to measure soluble and intracellular cytokine expression in the cell cultures and detect TLR2 expression on the surface of T cells. Expression of six different soluble cytokines was evaluated by CBA assay. To determine whether AaGroEL affects CD3+ T cells directly or not, purified CD3+ T cells or CD14+ cells were cultured with AaGroEL separately, and the quantity of soluble cytokine was measured. Results showed that sorted CD3+ cells produced soluble IL-6, TNFα-and IFNγ cytokines. Additionally, the intracellular cytokine staining data showed that AaGroEL-stimulated CD3+ cells were also TNFα-and IFNγ-positive. Moreover, AaGroEL-responsive T cells slightly increased their TLR2 expression. These findings suggest that CD3+ T cells produce cytokines in response to AaGroEL protein without requirements for other cells, such as CD14+ monocytes.Scientific and Technological Research Council of Turkey (TUBITAK 106T417

Interstrain differences in liver injury and one-carbon metabolism in alcohol-fed mice

Alcoholic liver injury is a major public health issue worldwide. Even though the major mechanisms of this disease have been established over the past decades, little is known about genetic susceptibility factors that may predispose individuals who abuse alcoholic beverages to liver damage and subsequent pathological conditions. We hypothesized that a panel of genetically diverse mouse strains may be used to examine the role of ER stress and one-carbon metabolism in the mechanism of inter-individual variability in alcoholic liver injury. We administered alcohol (up to 27 mg/kg/d) in high fat diet using intragastric intubation model for 28 days to male mice from 14 inbred strains (129S1/SvImJ, AKR/J, BALB/cJ, BALB/cByJ, BTBR T+tf/J, C3H/HeJ, C57BL/10J, DBA/2J, FVB/NJ, KK/HIJ, MOLF/EiJ, NZW/LacJ, PWD/PhJ, and WSB/EiJ). Profound inter-strain differences (more than 3-fold) in alcohol-induced steatohepatitis were observed among the strains in spite of consistently high levels of urine alcohol that was monitored throughout the study. We found that endoplasmic reticulum stress genes were induced only in strains with the highest liver injury. Liver glutathione and methyl donor levels were affected in all strains, albeit to a different degree. Most pronounced effects that were closely associated with the degree of liver injury were hyperhomocysteinemia and strain-dependent differences in expression patterns of one-carbon metabolism-related genes

Hepatic epigenetic phenotype predetermines individual susceptibility to hepatic steatosis in mice fed a lipogenic methyl-deficient diet

The importance of epigenetic changes in etiology and pathogenesis of disease has been increasingly recognized. However, the role of epigenetic alterations in the genesis of hepatic steatosis and cause of individual susceptibilities to this pathological state are largely unknown

Increased incidence of aflatoxin B1-induced liver tumors in hepatitis virus C transgenic mice

Viral hepatitis and aflatoxin B1 (AFB1) exposure are common risk factors for hepatocellular carcinoma (HCC). The incidence of HCC in individuals co-exposed to hepatitis C (HCV) or B virus and AFB1 is greater than could be explained by the additive effect, yet the mechanisms are poorly understood due to lack of an animal model. This study investigated the outcomes and mechanisms of combined exposure to HCV and AFB1. We hypothesized that HCV transgenic (HCV-Tg; expressing core, E1, E2, and p7, nucleotides 342–2771) mice will be prone to hepatocarcinogenesis when exposed to AFB1. Neonatal (7 days old) HCV-Tg or C57BL/6J wild-type mice were exposed to AFB1 (6 μg/g bw) or tricaprylin vehicle (15 μl/g bw) and male offspring were followed for up to 12 months. No liver lesions were observed in vehicle-treated wild type or HCV-Tg mice. Tumors (adenomas or carcinomas) and preneoplastic lesions (hyperplasia or foci) were observed in 22.5% (9 of 40) of AFB1-treated wild-type mice. In HCV-Tg, the incidence of tumorous or pre-tumorous lesions was significantly elevated (50%, 18 of 36), with the difference largely due to a 2.5-fold increase in the incidence of adenomas (30.5% vs 12.5%). While oxidative stress and steato-hepatisis were observed in both AFB1-treated groups, molecular changes indicative of the enhanced inflammatory response and altered lipid metabolism were more pronounced in HCV-Tg mice. In summary, HCV proteins core, E1, E2 and p7 are sufficient to reproduce the co-carcinogenic effect of HCV and AFB1 which is a known clinical phenomenon