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The objective of the present work was to apply self-organizing feature maps (SOFM) and multilayer perceptron (MLP) to evaluate the protective capacity of tert-butylhydroquinone (TBHQ), butylhydroxyanisole (BHA), and butylhydroxytoluene (BHT) antioxidants against the biodiesel oxidation reaction. For this, the antioxidant concentration and the biodiesel compliance parameters were used as continuous input variables and the type of antioxidant as a categorical. The SOFM proved to be an adequate tool for the classification of biodiesel samples containing antioxidants. The performance of the 5 most active networks of the model ranged from 89 to 99% for training, testing, and validation with an error below 1.42 × 10-4. Statistical tests applied to validate the model showed no significant difference between predicted and experimental values. The global sensitivity analysis showed that the relative protection factor (RPF) contributed with 34.89%, the antioxidant with 31.49%, the induction period with 10.69%, the water content with 6.00%, and the others all together with 16.93% in the construction of the regression models by MLP.

Aims Tert-butylhydroquinone (tBHQ) has been identified as an inhibitor of oxidative stress-induced injury and apoptosis in human neural stem cells. However, the role of tBHQ in osteoarthritis (OA) is unclear. This study was carried out to investigate the role of tBHQ in OA. Methods OA animal model was induced by destabilization of the medial meniscus (DMM). Different concentrations of tBHQ (25 and 50 mg/kg) were intraperitoneally injected in ten-week-old female mice. Chondrocytes were isolated from articular cartilage of mice and treated with 5 ng/ml lipopolysaccharide (LPS) or 10 ng/ml interleukin 1 beta (IL-1β) for 24 hours, and then treated with different concentrations of tBHQ (10, 20, and 40 μM) for 12 hours. The expression levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in blood were measured. The expression levels of interleukin 6 (IL-6), IL-1β, and tumour necrosis factor alpha (TNF-α) leptin in plasma were measured using enzyme-linked immunoabsorbent assay (ELISA) kits. The expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathway proteins, and macrophage repolarization-related markers, were detected by western blot. Results Tert-butylhydroquinone significantly attenuated cartilage destruction in DMM-induced mice in vivo. It demonstrated clear evidence of inhibiting IL-1β-induced chondrocyte apoptosis, inflammation, and differentiation defect in vitro. Meanwhile, tBHQ inhibited LPS-induced activation of NF-κB and MAPK signalling pathways, and also inhibited LPS-induced reactive oxygen species production and macrophages repolarization in vitro. Conclusion Taken together, tBHQ might be a potential therapeutic strategy for protecting against OA development. Cite this article: Bone Joint Res 2021;10(11):704–713.

The use of biolubricants as a replacement for petroleum-based products is becoming more and more important, due to the current global energy and crude oil scenario. Thus, the production of biolubricants (which could take place in biorefineries) should be as efficient as possible, obtaining high-quality products with suitable viscosity or oxidation stability values to compete with oil refineries. One of the ways to produce biolubricants is through double transesterification from vegetable oils, where the role of catalysts (usually homogeneous) is vital, as they can improve the yield of the process. However, they should be removed after the chemical reaction, which is difficult once the biolubricant is obtained. Otherwise, they could act as catalysts during oxidation, contributing to a further decrease in oxidation stability and provoking significant changes. To avoid this, antioxidant addition could be an interesting choice. The aim of this work was to assess TBHQ addition in frying oil biolubricants, monitoring properties such as viscosity, acid number, absorbance or TBHQ content (through voltammetry) during oxidation. TBHQ addition (2114 mg·L−1) kept the main quality parameters during oxidation compared to control samples. In contrast, TBHQ content decreased during oxidation (to 160 mg·L−1), which proved its antioxidant effect.

Polypropylene (PP) based active composite films were prepared by adding butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT), and tertiary butylated hydroquinone (TBHQ) antioxidants using the extrusion molding process. All concentrations of BHT, 2% to 3% BHA, and 3% TBHQ significantly increased the tensile strength (TS) of the composite films compared with control films. Increasing antioxidant concentration decreased TS values for BHT films, whereas an opposite trend was observed for BHA and TBHQ films. BHA at 2%, and TBHQ at all added concentrations significantly reduced elongation at break (Eb ) of the composite films compared to control films. Water vapor permeability (WVP) of 1% BHT film was not significantly different from control. However, other antioxidants especially at increased concentrations significantly increased WVP values. TBHQ films with 300% to 662% increase had the highest WVP and BHT films with 5% to 81% increase had the lowest WVP among composite films. All three antioxidants had a negative effect on the transparency of the films; however the effect of BHA at higher concentrations was greater. The antioxidants did not change the color attributes of the films. Films containing all antioxidants showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, which increased with increase in their concentration, especially for those containing 3 wt.% BHT and TBHQ. Overall, incorporating BHA and BHT into a PP matrix improved mechanical, barrier, antioxidant properties, and film appearance and consequently were proposed for the development of antioxidant active PP films. TBHQ film is not recommended for food packaging because of its weak mechanical properties (lower Eb and TS values, higher WVP, and greater migration).

Submitted by Daniella Santos (daniella.santos@ufma.br) on 2022-12-22T00:02:58Z No. of bitstreams: 1 SuringoFalcão.pdf: 720112 bytes, checksum: d1ee3ff0e3443d54a97e45a32b376e1c (MD5) Made available in DSpace on 2022-12-22T00:02:58Z (GMT). No. of bitstreams: 1 SuringoFalcão.pdf: 720112 bytes, checksum: d1ee3ff0e3443d54a97e45a32b376e1c (MD5) Previous issue date: 2022-03-18 FAPEMA CAPES Tert-butyl hydroquinone (TBHQ) is a phenolic antioxidant compound of synthetic origin widely used in the food and fuel industry. As it is a stable and low-volatile compound, TBHQ has a high efficiency in maintaining stability and delaying the oxidation of fuels and foods, but its excessive use is extremely harmful to health, making it necessary to control its use by people. competent bodies. In this sense, the present work aims to develop a photoelectrochemical platform for the detection of TBHQ using a fluorine-doped tin oxide (FTO) electrode modified with zinc oxide (ZnO) sensitized with copper selenide (Cu3Se2). The photoelectrochemical platform was named Cu3Se2/ZnO/FTO which showed an expressive variation in the photocurrent value against the TBHQ compound, when subjected to the presence of visible LED light, compared to the ZnO/FTO and Cu3Se2/FTO platforms. The characterization of the platforms was performed by electrochemical impedance spectroscopy (EIE), X-ray diffraction (XRD) and amperometry. Under the optimized experimental conditions, the proposed photosensor presented a linear response range from 0.4 to 290 µmol L-1 . The sensor was successfully applied for the determination of TBHQ in babassu methyl biodiesel and vegetable oil (soybean) samples showing recovery values for the analyte of 98.95% and 109.33%, respectively, suggesting good accuracy. O terc-butil hidroquinona (TBHQ) é composto antioxidante fenólico de origem sintética muito utilizado na indústria alimentícia e de combustível. Por ser um composto estável e ser pouco volátil, o TBHQ apresenta uma elevada eficiência em manter a estabilidade e retardar a oxidação de combustíveis e alimentos, mas o uso em excesso é extremamente nocivo à saúde fazendo-se necessário o controle do uso do composto pelos órgãos competentes. Diante do exposto, o presente trabalho tem como objetivo o desenvolvimento de uma plataforma fotoeletroquímica para a detecção do TBHQ empregando-se um eletrodo de óxido de estanho dopado com flúor (FTO) modificado com óxido de zinco (ZnO) sensibilizado com seleneto de cobre (Cu3Se2). A plataforma fotoeletroquímica foi denominada Cu3Se2/ZnO/FTO a qual apresentou uma expressiva variação no valor de fotocorrente frente ao composto TBHQ, quando submetido à presença de luz LED visível, em comparação às plataformas ZnO/FTO e Cu3Se2/FTO. A caracterização das plataformas foi realizada por espectroscopia de impedância eletroquímica (EIE), difração de raio-X (DRX) e amperometria. Sob as condições experimentais otimizadas, o fotossensor proposto apresentou um intervalo de resposta linear de 0,4 a 290 μmol L -1. O sensor foi aplicado com sucesso para a determinação de TBHQ em amostras de biodiesel metílico de babaçu e óleo vegetal (soja) mostrando valores de recuperação para o analito de 98,95% e 109,33%, respectivamente, sugerindo boa exatidão.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Esta tese apresenta um estudo sistemático sobre o efeito de partículas de alumina (Al2O3) na superfície de eletrodos de carbono vítreo (glassy-carbon electrode, GCE) frente as determinações voltamétricas e amperométricas de diversos analitos. A oxidação eletrocatalítica de catecol (CT), dopamina (DP) e terc-butilhidroquinona (TBHQ) em GCE modificado com nanopartículas Al2O3 sintetizadas em diferentes estruturas e morfologias foi investigada. A maior atividade eletroquímica para a oxidação de CT, DP e TBHQ foi verificada no GCE polido em suspensão de α-Al2O3 em comparação com as superfícies modificadas com γ-Al2O3 e -Al2O3. Além disso, verificou-se que o efeito da estrutura da Al2O3 é predominante em relação ao efeito da área superficial das partículas, sendo a modificação com Al2O3 mais estável em GCE do que em superfícies de ouro e platina. A alta estabilidade da superfície do GCE modificado com α-Al2O3 foi atestada por detecção amperométrica dos compostos fenólicos. A oxidação eletroquímica do naproxeno (NPX) foi demonstrada utilizando o GCE modificado com α-Al2O3 e os resultados obtidos foram vantajosos com aumento de corrente e efeito catalítico, resultando em um sensor altamente sensível. Juntamente com o NPX, estudos voltamétricos também foram realizados para o ibuprofeno (IBF). Simulações de dinâmica molecular mostraram interação mais forte do NPX do que IBF com sítios de α-Al2O3. O GCE modificado com α-Al2O3 demonstrou ação catalítica também na redução da molécula de 2,4,6-trinitrotolueno (TNT). Os três picos de redução característicos do TNT foram deslocados para potenciais menos negativos com resolução de pico melhorada, combinada com aumento na corrente e sensibilidade analítica. A redução eletroquímica do oxigênio dissolvido também foi significativamente aumentada pela presença de α-Al2O3. Por fim, foi demonstrado que a α-Al2O3 residual na superfície do GCE (comumente usada para polimento de eletrodos) afeta os parâmetros eletroquímicos de antioxidantes (ácido caféico, ácido gálico, ácido clorogênico, catequina, rutina e quercetina) em amostras de alimentos (chá e vinho) obtidos por voltametria e usados para o cálculo da atividade antioxidante, resultando em valores discordantes. Os resultados mostraram aumento substancial de corrente (e carga) no GCE modificado com α-Al2O3 e o Índice Eletroquímico (parâmetro que indica atividade antioxidante) calculado foi consideravelmente aumentado. Dessa maneira, conclui-se que a modificação da superfície do GCE com α-Al2O3 é uma estratégia interessante para aumentar sensibilidade analítica e a detectabilidade do eletrodo para vários compostos eletroativos. This thesis presents a systematic study of the effect of alumina (Al2O3) particles on the surface of glassy carbon electrodes (GCE) in the face of voltammetric and amperometric determinations of several analytes. The electrocatalytic oxidation of catechol (CT), dopamine (DP) and tert-butylhydroquinone (TBHQ) on GCE modified with alumina nanoparticles (Al2O3) synthesized in different structures and morphologies was investigated. The highest electrochemical activity for the oxidation of CT, DP was verified using the polished GCE in suspension of α-Al2O3 in comparison with the surfaces modified with γ- Al2O3 and -Al2O3. In addition, it was found that the effect of the Al2O3 structure is predominant in relation to the effect of the surface area of the particles, being the modification with alumina more stable on GCE than on gold surfaces and on platinum. The high stability of the α-Al2O3 modified GCE surface was attested by amperometric detection of phenolic compounds. The electrochemical oxidation of naproxen (NPX) is demonstrated using the modified GCE with the α-Al2O3 particles and the results obtained were advantageous with increased current and catalytic effect, resulting in a highly sensitive sensor. Together with NPX, voltammetric studies were also carried out for ibuprofen (IBF). Molecular dynamics simulations showed a stronger interaction of NPX than IBF with α-Al2O3 sites. The GCE modified with α-Al2O3 also demonstrated catalytic action in reducing the 2,4,6-trinitrotoluene (TNT) molecule. The three reduction peaks characteristic of TNT were shifted to less negative potentials with improved peak resolution, combined with increased current and analytical sensitivity. The electrochemical reduction of dissolved oxygen was also significantly increased by the presence of α-Al2O3. Finally, it was demonstrated that the residual α-Al2O3 on the GCE surface (commonly used for polishing electrodes) affects the electrochemical parameters of antioxidants (caffeic acid, gallic acid, chlorogenic acid, catechin, rutin and quercetin) and food samples (tea and wine) obtained by voltammetry and used to calculate the antioxidant activity, resulting in discordant values. The results showed a substantial increase in current (and charge) on the GCE modified with α-Al2O3 and the calculated Electrochemical Index (parameter that indicates antioxidant activity) was considerably increased. Thus, it is concluded that the modification of the GCE surface with α-Al2O3 is an interesting strategy to increase the analytical sensitivity and the detectability of the electrode for various electroactive compounds. Tese (Doutorado)

Fine particulate matter (PM2.5) from poultry houses has adverse effects on the health of animals and workers. Tert-butylhydroquinone (TBHQ), an antioxidant, is widely used in feed additives. The present study investigated the effects of TBHQ on broiler house PM2.5-induced damage in chicken primary alveolar epithelial cells (AECII) extracted from 16-day-old chicken embryos using the method of differential adhesion. AECII were exposed to PM2.5 and TBHQ alone or in combination, and then, cell membrane integrity, pyroptosis, and necroptosis were detected. Our results showed that PM2.5 from broiler houses caused cell rupture and loss of cell membrane integrity. This result was confirmed by the obvious increases in lactate dehydrogenase (LDH) release and propidium iodide (PI)-positive cells compared to the control group. In addition, the intracellular reactive oxygen species (ROS) levels and the expression levels of pyroptosis-related genes (NLRP3, IL-18, IL-1β) and necroptosis-related genes (RIPK3) were also significantly enhanced. However, TBHQ significantly inhibited intracellular ROS, improved cell viability, and reduced the release of LDH and the number of PI-positive cells compared to those in the PM2.5 group. The expression levels of pyroptosis-related genes (Caspase-1, NLRP3, IL-18, IL-1β) and necroptosis-related genes (RIPK3) were also significantly decreased in the co-treatment group. In summary, these results indicated that TBHQ can alleviate PM2.5-mediated cell pyroptosis and necroptosis in chicken AECII and provide a basis for overcoming the danger that air pollutants from broiler houses pose to the health of chickens.

Uticaj ekstraćelijskim signalima regulisanih kinaza (ERK), proteinskih kinaza B (PKB; AKT) i proteinskih kinaza C (PKC) na adultne ćelija su dobro proučeni ali postoji relativno malo podataka o njihovim efektima tokom embriogeneze. U cilju definisanja uloga Erk, Akt i Pkc signalizacije tokom rane embriogeneze, embrioni riba zebrica su tretirani farmakološkim inhibitorima i stimulatorima ovih signalnih puteva. Rezultati su pokazali da Erk inhibiše eksprimiranje gena za glutation S-transferazu Pi (gstp1-2) i citohrom P450 1a (cyp1a) koji učestvuju u metabolizmu ksenobiotika i održavanju redoks ravnoteže tokom rane embriogeneze. Inhibitorni efekat Erk na eksprimiranje gstp1-2 se ostvaruje preko aktivacije transkripcionog faktora Creb (engl. cAMP response element-binding protein). Tokom oksidativnog stresa izazvanog terc-butilhidrokinonom (tBHQ), nije došlo do aktivacije Erk, te je i izostao efekat ove kinaze na tBHQ zavisnu indukciju eksprimiranja gstp1-2. Forbol 12-miristat 13-acetat (PMA) je doveo do povećanja fosforilacije Erk, ali nije menjao eksprimiranje gstp1-2. Inhibicija aktivnosti kinaza Erk sa U0126 je omogućila eksprimiranje gstp1-2 kod embriona tretiranih sa PMA. Globalna aktivacija Pkc izazvana delovanjem PMA je dovela do pojave razvojnih deformiteta, smanjenja stope preživljavanja, pojave apoptotičnih ćelija u regionu mozga, povećanja eksprimiranja proapoptotičnih gena casp9 (kaspaza 9) i puma (engl. p53 upregulated modulator of apoptosis) i gena za antioksidativne enzime superoksid dismutazu 2 (Sod2) i katalazu (Cat) kod embriona riba zebrica. Inhibicija Pkc je poboljšala stopu preživljavanja, smanjila apoptozu u mozgu i smanjila eksprimiranje casp9 i puma u embrionima izloženim PMA, ali nije sprečila pojavu deformacija niti oksidativni stres. Rezultati u ovoj disertaciji ukazuju da Erk deluje inhibitorno na eksprimiranje gena gstp1-2 i cyp1a u neometanim uslovima razvoja embriona, dok aktivacija ove kinaze sprečava povećanje gstp1-2 tokom oksidativnog stresa. Prekomerna aktivacija Pkc tokom rane embriogeneze zebrica dovodi do apoptoze i smanjene stope preživljavanja embriona riba zebrica. Extracellular signal regulated kinase (ERK), protein kinase B (PKB, i.e. AKT) and protein kinase C (PKC) signaling pathways and their impact on the adult cell functions are well studied, but only few data exist regaridng their role during embryogenesis. In order to reveal the role of these signaling pathways during early embriogenesis, zebrafish embryos were treated with inhibitors or activators of the above mentioned signaling pathways. The results showed that Erk inhibited transcription of glutation S-transferase Pi (gstp1-2) and cytochrome P450 1a (cyp1a) genes, which are involved in metabolism of xenobiotics and redox regulation in embryos. The inhibitory effect of Erk is transmitted through the Creb (cAMP response element-binding protein) transcription factor. During oxidative stress provoked by tert-butylhydroquinone (tBHQ), the Erk activity was not enhanced and therefore it failed to prevent the stimulatory effect of tBHQ on gstp1-2 gene expression. On the other hand, inhibition of the Erk acitivity by U0126 allowed phorbol 12-myristate 13-acetate (PMA) to induce gstp1-2 during oxidative stress. Addition of PMA caused various developmental deformities, decreased survival rate, increased the number of apoptotic cells in the brain region, and enhanced the expression of proapoptotic casp9 (Caspase 9) and puma (p53 upregulated modulator of apoptosis, puma) and antioxidative sod2 (superoxide dismutase 2) and cat (catalase) genes in zebrafish embryos. The inhibition of Pkc by pharmalogical inhibitor improved overall survival rate, reduced apoptosis in the brain and decreased expression of casp9 and puma in the PMA-exposed embryos, but did not prevent deformities and oxidative stress. These data suggest that Erk inhibits gstp1-2 and cyp1a during normal embryogenesis. The activation of Erk during oxidative stress can also prevent the expression of gstp1-2. Direct over-activation of Pkc during early embryogenesis of zebrafish is associated with apoptosis and decreased survival rate of the embryos.

Flavonoids are a major component of Ginkgo biloba extract (GBE). Several studies have investigated chelate formation and the redox reaction between flavonoids and metal ions; however, the effect of mineral supplements on the results from the analysis of the flavonol glycoside content in products containing GBE dietary supplement remains unknown. In this study, the effects of commonly used mineral supplements on the recovery of quercetin from GBE-containing dietary supplements were investigated using conventional methods of flavonol glycoside determination. Mineral supplements containing Zn (II), Mn (II), and Fe (II) did not affect quercetin recovery, whereas Cu (II) and Fe (III) significantly reduced recovery (P

Background Maize oil is abundantly used in foods and feeds and is highly susceptible to oxidation. Consequently, commercially available antioxidants should be evaluated for effectiveness against lipid oxidation in swine diets. Our study was conducted to evaluate growth performance of nursery pigs fed oxidized maize oil and to determine effects of using antioxidants on oxidative status in a 2 × 2 factorial design. Two hundred eight weaned pigs were blocked by initial BW into 13 blocks, resulting in 4 pigs per pen and 13 pens per treatment. Dietary treatments included 6% unoxidized or oxidized maize oil, and 0 or 60 mg/kg of tert-butylhydroquinone (TBHQ), which was added after lipid oxidation. Data for growth performance were collected from 5 time periods of a two-phase feeding program (Phase 1 = d 0 to 12 and Phase 2 = d 13 to 34). Serum and liver samples were collected from one pig per pen, which had initial BW closest to average BW to determine oxidative status on d 34. Results Oxidized maize oil was heated for 12 h at 185 °C with 12 L/min of air, yielding a peroxide value (PV) of 5.98 mEq O2/kg and TBARS of 0.11 mg MDA eq/g. Addition of TBHQ to diets containing oxidized maize oil decreased PV by 37% and increased the oil stability index by 69%. Final BW, ADG, ADFI, and G:F of pigs were not different among the four dietary treatments. However, pigs fed oxidized maize oil tended (P

ObjectivesTo investigate the protective effects and mechanism of antioxidant TBHQ on renal damage caused by doxorubicin chemotherapy in mice with hepatic cancer.MethodsCell H22 of mice with hepatic cancer which was subcultured for three times was subcutaneously transplanted to the groin of right lower limb of 45 SPF Kunming mice to establish the transplanted tumor model. The doxorubicin chemotherapy group and antioxidant intervention group received intraperitoneal injection of ADM (1 mg/kg·0.2 mL/2 d). The model control group received normal saline (NS) of the same volume at the same time. 1% TBHQ was added into the diet of mice of the antioxidant intervention group. Seven weeks later, morning urines and peripheral blood were randomly collected to detect UAlb, UCr, BUN, Scr and UAlb/Cr levels. All mice were beheaded. The renal tissues were made into homogenate, and SOD, T-AOC and MDA content in tissues were detected followed by cell lysis. All data were processed using SPSS19.0.ResultsThe UAlb/Cr, BUN, Scr and MDA of doxorubicin chemotherapy group were significantly higher those of model control group and the activities of SOD, T-AOC in doxorubicin chemotherapy group were lower than those of model control group (P

A novel compound, 6,6'-(butane-1,1-diyl)bis(4-methylbenzene-1,2-diol) (BMB), was synthesized through an acid-catalyzed condensation reaction between 4-methylcatechol (HPC) and butyraldehyde. When evaluated by the Rancimat and deep frying methods, BMB exhibited a stronger antioxidant activity than TBHQ. Its DPPH radical scavenging activity was also fairly higher than TBHQ, but lower compared to its mother phenol, HPC, due to its relative ease of binding DPPH•. BMB had the strongest scavenging ability of the 4-methylcatechol analogues reported to date. It could be used effectively to retard lipid peroxidation in both moderate and high temperature food preparations. Un nuevo compuesto, 6,6'-(butano-1,1-diil)bis(4-metilbenceno-1,2-diol) (BMB) fue sintetizado mediante una reacción de condensación catalizada por ácido entre el 4-metilcatecol (HPC) y el butiraldehído. Cuando se evaluó mediante los métodos Rancimat y de fritura, el BMB mostró una actividad antioxidante más fuerte que el TBHQ. Su actividad de eliminación de radicales DPPH también fue bastante mayor que la del TBHQ, pero menor en comparación con el fenol de partida, HPC, debido a su relativa facilidad para unirse a DPPH•. BMB tiene una actividad de eliminación más fuerte que los análogos de 4-metilcatecol reportados hasta la fecha. Podría usarse eficazmente para retardar la peroxidación de lípidos en la preparación de alimentos a temperatura moderada y alta.

AOCS Official Method Ce 6-86 “Antioxidants, Liquid Chromatographic Method” was originally developed to confirm the correct antioxidant was added at the specified concentration to refined oils. Today, this method is increasingly utilized to validate that antioxidants are absent from oil products. False positive results can have a significant impact on the ability to sell products in specific markets and can impart additional business expenditures for conclusive secondary analyses. In the current work, quantification of tert-butylhydroquinone (TBHQ) in crude canola/rapeseed oil using liquid chromatography (LC) with ultraviolet (UV) detection was compromised by an interfering peak. Analyses using liquid chromatography-mass spectrometry (GC–MS) and high-resolution accurate mass LC–MS identified the interferent as 2,6-dimethoxy-4-vinylphenol (canolol), an endogenous compound present in crude canola/rapeseed oil. Resolution of canolol and TBHQ using LC-UV can be achieved via minor modification of the chromatographic conditions.

NRF2 is a nuclear transcription factor activated in response to oxidative stress and related with metabolizing of xenotoxic materials and ABC transporter mediated drug resistance. We studied the expression of mRNAs under the siRNA-mediated knockdown of NRF2 and tBHQ-treated condition in AsPC-1 metastatic pancreatic cancer cell line to understand the AsPC-1 specific role(s) of NRF2 and further to investigate the relationship between drug resistance and metastatic plasticity and mobility of AsPc1. Here we show that the genes of aldo–keto reductases, cytochrome P450 family, aldehyde dehydrogenase, thioredoxin reductase, ABC transporter and epoxide hydrolase responsible for drug metabolism or oxidative stress concisely responded to NRF2 stabilization and knockdown of NRF2. In addition the expression of PIR, a candidate of oncogene and KISS1, a suppressor of metastasis were affected by NRF2 stabilization and knockdown. Our result provide comprehensive understanding of NRF2 target genes of drug response, oxidative stress response and metastasis in AsPc-1 metastatic pancreatic cancer cell line. Electronic supplementary material The online version of this article (doi:10.1007/s13258-014-0253-2) contains supplementary material, which is available to authorized users.

نانوفیبر سلولزی اصلاح شده با اسید چرب (MCNF) و آنتی اکسیدان ترت بوتیل هیدروکینون (TBHQ) به فیلم پلی لاکتیک اسید (PLA) اضافه شدند و تأثیر آنها بر ریز ساختار، ویژگی‌های حرارتی، مکانیکی و بازدارندگی فیلم PLA مورد بررسی قرار گرفت. ریز ساختار سطح شکست فیلم‌ها توسط میکروسکوپ الکترونی روبشی نشر میدانی (FE-SEM) مورد مطالعه قرار گرفت. نتایج آزمون پراش اشعه ایکس (XRD) نشان داد که بلورینگی فیلم‌‌های نانوکامپوزیت حاوی MCNF بیشتر از فیلم خالص PLA و فیلم‌های فعال حاوی TBHQ بود. نتایج گرماسنجی پویشی افتراقی نشان داد که با افزودن هر دو ترکیب، دمای انتقال شیشه‌ای و دمای ذوب فیلم ها تغییر می کند. افزودن 3% TBHQ باعث کاهش معنی‌دار (05/0˂p) در استحکام کششی فیلم PLA از 52/10 به MPa 03/6 شد در صورتیکه، استحکام مکانیکی فیلم با افزودن MCNF بهبود یافت. نفوذپذیری نسبت به بخار آب و اکسیژن نیز با افزودن TBHQ و MCNF بترتیب افزایش و کاهش یافت.

The aim of the current investigation is to evaluate the efficiency of tertiary butyl hydroquinone (TBHQ) as an antioxidant in edible oil like palm oil (Elaeis guineensis) by physical, chemical and ultrasonic properties. The effects of the varying amounts of TBHQ on the oxidation stability of palm oil have been investigated. The antioxidant incorporated palm oil system and control oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for 4 days consecutively. The parameters used to assess the thermal degradation and oxidation properties of the palm oil include ultrasonic velocity, viscosity and density. Adiabatic compressibility, intermolecular free length, relaxation time, and acoustic impedance have been calculated from experimental data. The effect of thermal ageing on the physical properties of the oil was confirmed by chemical analysis, which included free fatty acid, total polar compounds, and estimation of fatty acids profile by gas chromatography (GC). The chemical changes were studied by FT-IR bands. The results obtained from ultrasonic studies have shown improvement in oxidative stability and retardation in thermal degradation of the antioxidant-loaded oil in comparison with the base oil. Hence, the ultrasonic velocity and acoustical parameters used for assessment of stability of frying oil and palm oil with TBHQ can be recommended for repeated frying without adverse effects on the physical properties.

The current ANS Panel statement is a refined exposure assessment of tertiary‐butyl hydroquinone (TBHQ, E 319) when used as a food additive. TBHQ (E 319) is authorised as a food additive in the EU with an acceptable daily intake (ADI) of 0.7 mg/kg body weight (bw), as established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1998 and confirmed by EFSA in 2004. In 2004, the EFSA Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) adopted an opinion on the safety in use of TBHQ (E 319) in fats and oils used for human consumption. In that opinion, the Panel concluded that the exposure in adults did not exceed the ADI, however, if TBHQ (E 319) was to be used in infant formulae, the exposure in infants could exceed the ADI. Following this conclusion, EFSA performed a refined exposure assessment for TBHQ (E 319) based on individual food consumption data available within the EFSA Comprehensive European Food Consumption Database, on newly submitted data on the actual usage levels of TBHQ (E 319) and analytical data provided by the food industry and Member States. EFSA ANS Panel concluded that, using the maximum permitted levels, exposure estimates exceed the ADI of 0.7 mg/kg bw per day at the high level for toddlers and children, however, in the refined exposure scenarios, the ADI was not exceeded in any of the population groups.

8 pages, 1 figure.-- Review., [EN] The action of antioxidants to delay lipid oxidation in fats and oils is well known although most of the information is related to their effects at room temperature during storage or at the moderate temperatures of the accelerated tests to measure oil stability. However, oxidation at the high temperatures of food processes like frying, is more complex because the availability of air is unknown and both oxidative and thermal reactions are simultaneously involved. In this review, the main studies defining the action of natural and synthetic antioxidants at frying temperatures are summarized. This review has been divided into two main parts concerning the information on natural antioxidants, i.e. tocopherols and other phenolic compounds present in specific oils like olive, sesame and rice bran oils, and on synthetic antioxidants, i.e. BHA, BHT and TBHQ., [ES] La acción de antioxidantes para retrasar la oxidación en grasas y aceites es bien conocida aunque la mayor parte de la información está relacionada con su actividad a temperatura ambiente durante el almacenamiento o a las temperaturas moderadas de los ensayos de oxidación acelerada. Sin embargo, su efectividad a la temperatura elevada de procesos como la fritura es más compleja debido a la existencia de reacciones oxidativas y térmicas que tienen lugar simultáneamente. En esta revisión, se resumen los estudios principales que definen la acción de los antioxidantes naturales y sintéticos durante el proceso de fritura. Se ha dividido en dos partes que resumen la acción y los compuestos de degradación de los antioxidantes naturales, es decir, tocoferoles y otros compuestos fenólicos presentes en aceites de oliva, sésamo y salvado de arroz, y de los principales antioxidantes sintéticos como BHA, BHT y TBHQ., This work was supported by MICINN (projects AGL 2007-62922 and AGL 2007-63647) and Junta de Andalucía.

Tuner, Hasan (Balikesir Author), The effects of gamma radiation on tertiary butylhydroquinone (TBHQ) are reported using electron spin resonance (ESR) spectroscopy. While unirradiated (control) TBHQ exhibited no ESR signal, irradiated one presented an ESR spectrum with five characteristic resonance peaks extended over a magnetic field region of 1.5 mT. Variations of the heights of the resonance peaks and the spectrum area as function of the microwave power, applied dose, storage time, and temperature were studied. The kinetic features and spectroscopic parameters of the species responsible for the experimental ESR spectrum were investigated by annealing studies performed at four different temperatures and simulation calculations, respectively. A model based on the presence of two species having different kinetic and spectroscopic features was found to describe best the experimental results. The dosimetric potential of TBHQ was also investigated, and it was concluded that the discrimination of irradiated TBHQ from unirradiated one was possible even long after the radiation treatment, and that radiation doses above 5 kGy could be measured with an accuracy better than 3% by using TBHQ. Two tentative radical species were proposed.

Sunflower oil is one of the vegetable oils most susceptible to oxidative reaction. Therefore the presence of natural (tocopherol) and/or synthetic (TBHQ) antioxidants is a prerequisite to secure the stability of this oil during its shelf life, especially with the increased use of PET packaging. On determining the total tocopherol content in 10 samples of deodorized sunflower oils, high losses in total tocopherol during deodorization were identified. In order to facilitate researche involving oxidative stability of vegetable oils, a method for isolated quantification of TBHQ using the isocratic elution system was developed.

Sunflower oil is one of the vegetable oils most susceptible to oxidative reaction. Therefore the presence of natural (tocopherol) and/or synthetic (TBHQ) antioxidants is a prerequisite to secure the stability of this oil during its shelf life, especially with the increased use of PET packaging. On determining the total tocopherol content in 10 samples of deodorized sunflower oils, high losses in total tocopherol during deodorization were identified. In order to facilitate researche involving oxidative stability of vegetable oils, a method for isolated quantification of TBHQ using the isocratic elution system was developed.

Phosphatidylinositol 4,5-bisphosphate (PIP2) is a versatile regulator of TRP channels. We report that inclusion of a PIP2 analogue, PIP2 1,2-dioctanoyl, does not induce non-capacitative Ca2+ entry per se but enhanced Ca2+ entry stimulated either by thrombin or by selective depletion of the Ca2+ stores in platelets, the dense tubular system, using 10 nM TG, and the acidic stores, using 20 μM 2,5-di-(tert-butyl)-1,4-hydroquinone (TBHQ). Reduction of PIP2 levels by blocking PIP2 resynthesis with Li+ or introducing a monoclonal anti-PIP2 antibody, or sequestering PIP2 using poly-lysine, attenuated Ca2+ entry induced by thrombin, TG and TBHQ, and reduced thrombin-evoked, but not TG- or TBHQ-induced, Ca2+ release from the stores. Incubation with the anti-hTRPC1 antibody did not alter the stimulation of Ca2+ entry by PIP2, whilst introduction of anti-hTRPC6 antibody directed towards the C-terminus of hTRPC6 reduced Ca2+ and Mn2+ entry induced by thrombin, TG or TBHQ, and abolished the stimulation of Ca2+ entry by PIP2. The anti-hTRPC6 antibody, but not the anti-hTRPC1 antibody or PIP2, reduced non-capacitative Ca2+ entry by the DAG analogue 1-oleoyl-2-acetyl-sn-glycerol. In summary, hTRPC6 plays a role both in store-operated and in non-capacitative Ca2+ entry. PIP2 enhances store-operated Ca2+ entry in human platelets, most probably by stimulation of hTRPC6 channels.

Dental resin monomers like HEMA (2-hydroxylethyl methacrylate) exert cytotoxicity via apoptosis which is causally related to the elevated production of ROS (reactive oxygen species) [1]. Here, we hypothesized that the activation of the redox-sensitive transcription factor Nrf2 [2] as an antioxidant cell response counteracts HEMAinduced cell death through the Nrf2-regulated expression of enzymatic antioxidants. RAW264.7 mouse macrophages were preincubated with t-BHQ (t-butyl-hydroquinone) (0-50μM) which is a classical inducer of the Nrf2 pathway. Then, cells were exposed to HEMA (0-8 mM) for 24h with or without t-BHQ. Expression of Nrf2 and Nrf2-regulated enzymatic antioxidants (catalase, peroxiredoxin, thioredoxin 1, thioredoxin reductase, heme oxygenase-1, glucose 6-phosphate dehydrogenase, transaldolase) was detected by Western blotting. The percentage of cells undergoing apoptosis or necrosis was determined by flow cytometry after Annexin-V-FITC/propidium iodide (PI) staining. Differences between medians (plus 25%/75% percentiles) were statistically analysed (Mann-Whitney-U test). The expression of Nrf2 and Nrf2-regulated enzymatic antioxidants increased in cell cultures exposed to t-BHQ and was further enhanced by HEMA. The number of viable cells detected in the untreated samples (97%) significantly decreased in a concentration-dependent manner in cultures exposed to HEMA. About 61% viable cells were found after exposure to 8 mM HEMA along with the increased number of cells in the various phases of cell death. However, the presence of t-BHQ protected cells from HEMA-induced cell death through a shift from necrotic cells (PI-stained) and late apoptotic (Annexin-V+PI) to the early apoptotic ones (Annexin-V). The number of cells in late apoptosis and necrosis significantly decreased about 4-fold in cultures treated with 8mM HEMA in the presence of 50μM t-BHQ compared to cultures exposed to 8 mM HEMA alone. These results provide evidence that the increased expression of Nrf2 and Nrf2-regulated enzymatic antioxidants is an adaptive cell response to inhibit HEMA-induced cell death., Italian Journal of Anatomy and Embryology, Vol. 120, No. 1 (Supplement) 2015

Corn oil obtained from a Brazilian industry, free from antioxidants and citric acid, added of different tertiary butylhydroquinone (TBHQ) concentrations, was submitted to accelerated oxidation in the Schaal oven test at 63°C for 120 hours and for 168 hours in a photooxidation chamber. Peroxide and absorptivity values at 232nm and 270nm were determined for this oil. From the Schaal oven test results, the best and the economical TBHQ doses were determined to this oil. Afterwards, a shelf life experiment was conducted and confirmed 115mg.kg-1 TBHQ as the best and economical dose for that oil.Óleo de milho obtido de uma indústria brasileira isento de antioxidantes e de ácido cítrico foi adicionado de diferentes concentrações de TBHQ e submetido a testes acelerados de oxidação em estufa a 63(0)C por 120 horas e em câmara de fotoxidação por 168 horas. Foram analisados o índice de peróxido e as absortividades em 232nm e 270nm deste óleo. A partir dos resultados do teste em estufa, calculou-se a melhor dose e a dose econômica do antioxidante TBHQ. Em seguida foi conduzido, então ensaio ao ambiente, que confirmou a concentração de 115mg.kg-1 TBHQ como a dosagem econômica e melhor dose para o óleo sob estudo.

Doutoramento em Engenharia Química In recent years, the search for a environmentally friendly products has increased. One of the major challenges has been the demand for biodegradable materials that can replace plastic. If a few decades ago, plastic replaced, for example, the ivory in billiard balls, and in other products, saving the lives of thousands elephants, nowadays a replacement for that plastic is being searched, to prevent the change of the environmental conditions, essential to life in harmonly with the fauna and flora that the human specie has, in recent years, destroyed. Plastic is a petroleum derivate, whose price has been growing exponentially, mainly due to the fact of beind a cheap material and also to enable the production of products that are essential to modern life. Therefore, the petrochemical era is going to come to an end and a new environmentally sustainable era, based on biodegradable materials from renewable sources, will follow. The change to green routes only will be possible with the support of the major companies, and the implementation of drastic governmental law. Poly(lactic acid), PLA, is produced from the lactose present in the corn or sugarcane and has been intensively studied in recent years because if some limitants properties required its extrusion are overcome, it has the potential to replace the traditional polymers. PLA have high brittleness, low toughness and low tensile elongation. In this work, natural antioxidant (alpha-tocopherol) and synthetics antioxidants (BHT ant TBHQ) were added to the PLA with the aim not only to improve their flexibility, but also to create an active packaging to extend the shelf life of the foods and improve the organoleptic properties by preventing food losses. The impact of the addition of antioxidants into the PLA films, in its mechanical, thermal and barrier properties were studied by FTIR, DSC, SEM, AFM, DMA, TGA, QCM and time-lag techniques. Nos últimos anos temos assistido à procura de produtos amigos do ambiente. Um dos maiores desafios tem sido a procura de materiais biodegradáveis que possam substituir materiais vulgarmente designados por “plástico”. Se há dezenas de anos o plástico veio, por exemplo, substituir o marfim nas bolas de bilhar, salvando vidas de milhares de elefantes, hoje, procuramos um substituto para esse plástico, de forma a preservar as condições ambientais que nos permitem viver harmoniosamente com a restante fauna e flora, e que a espécie humana tem, nos últimos anos, vindo a destruir. O plástico é um derivado do petróleo, cujo preço tem vindo a crescer exponencialmente, devido ao facto de ser barato e possuir propriedades que permitem desenhar produtos essenciais à vida quotidiana. Por isso, precisamos de sair da era petroquímica e entrar numa nova era ambientalmente sustentável, baseada em materiais biodegradáveis provenientes de fontes renováveis. Esta mudança para rotas “verdes”, só será possível com o apoio de grandes empresas, e medidas governamentais drásticas. O poliácido láctico, PLA, produzido a partir da lactose presente no amido ou no açúcar, tem sido intensivamente estudado nos últimos anos e possui potencial para substituir os tradicionais polímeros derivados do petróleo, se forem melhoradas algumas propriedades necessárias ao processamento por extrusão. O PLA, é muito frágil, pouco resistente e pouco flexível. Neste trabalho foram adicionados antioxidantes naturais (alfa-tocoferol) e sintéticos (BHT e TBHQ) ao PLA com o objetivo não só de melhorar as suas propriedades mecânicas, mas também de criar uma embalagem ativa que prolongue o prazo de validade dos alimentos e melhore as suas propriedades organoléticas prevenindo alterações ou perda de sabor. O impacto da adição destes antioxidantes nas propriedades originais do PLA a nível mecânico, térmico e de barreira foi estudado pela utilização das técnicas de FTIR, DSC, SEM, AFM, DMA, TGA, QCM e time-lag.

Doutoramento em Engenharia Química Submitted by Alexandra Bastos (alexandrabastos@ua.pt) on 2015-06-25T13:03:52Z No. of bitstreams: 1 tese.pdf: 9235080 bytes, checksum: 218e5f93a8bd884fa9c2738b4616a6ab (MD5) Made available in DSpace on 2015-06-25T13:03:52Z (GMT). No. of bitstreams: 1 tese.pdf: 9235080 bytes, checksum: 218e5f93a8bd884fa9c2738b4616a6ab (MD5) Previous issue date: 2014-06-03

Two novel compounds bearing four hydroxyphenyl groups were synthesized by the acid-catalyzed condensation reaction of glyoxal with toluhydroquinone (THQ) or tertiary butylhydroquinone (TBHQ), respectively. The antioxidant activity of the newly synthesized compounds was assessed by the Rancimat test, a 2,2-diphenyl 1-picrylhydrazyl (DPPH) assay and reducing power assay. In the Rancimat antioxidant test using lard oil as substrate, the performance of two newly synthesized compounds was superior to TBHQ at 140 °C. It was suggested that two newly synthesized compounds can be used to improve the oxidative stability of lipid products during high temperature processing. With regard to the DPPH radical scavenging activity and reducing power, the performance of synthesized compounds was inferior to their mother compounds, respectively. The results show that the DPPH radical scavenging activity and reducing power of a compound did not correlate with its ability to retard lipid oxidation.Dos nuevos compuestos con cuatro grupos hidroxifenilo se sintetizaron mediante reacción de condensación catalizada por glioxal con toluhidroquinona (THQ) o terbutilhidroquinona (TBHQ), respectivamente. La actividad antioxidante de los compuestos sintetizados se evaluó mediante Rancimat, método del 2,2-difenil-1-picrilhidrazil (DPPH) y poder reductor. Para el ensayo de Rancimat se usó manteca de cerdo como sustrato, la efectividad de los dos compuestos recién sintetizados fue superior a la del TBHQ a 140 °C. Se sugiere que los compuestos sintetizados se pueden utilizar para mejorar la estabilidad oxidativa de productos lipídicos durante el procesamiento a alta temperatura. Con respecto a la actividad de eliminación de radicales DPPH y poder reductor, la efectividad de los compuestos sintetizados fue inferior a los compuestos matrices. Los resultados mostraron que la actividad de eliminación de radicales DPPH y poder reductor de un compuesto no se correlacionó con su capacidad para retardar la oxidación lipídica.

Stability plays an important role in the development of a new drug product. High Performance Liquid Chromatography (HPLC) is considered a stability indicating method of analysis. It is widely used in the pharmaceutical industry for the quantification of small organic molecules during stability testing. Previous stability studies conducted on Pheroid™-based drug products, experienced problems with the generation of reliable data by means of HPLC analysis. With these studies it was concluded that the inconclusive results could either be attributed to the stability of the delivery system itself and the compatibility of the active pharmaceutical ingredients (API's) with the delivery system, or to the usage of unsuitable HPLC methods. The aims of this study were to: i. determine if the Pheroid™ delivery system changes significantly over time at accelerated storage conditions and how these changes influence the HPLC analysis, ii. determine the effect of the anti-oxidant tert-butylhydroquinone (TBHQ) on the stability and HPLC analysis of the Pheroid™ delivery system, and iii. to suggest a suitable approach for the analysis of Pheroid™-based drug products. Pheroid™ microsponges, containing no API's, were prepared and stored for a period of three months at 5°C, 25°C+60%RH, 30°C+65%RH and 40°C+75%RH. Two of the four Pheroid™ formulations contained an extra anti-oxidant, namely TBHQ. Monthly HPLC analyses were done using existing methods for mefloquine and artesunate. In addition to HPLC analysis, particle size analysis and Confocal Laser Scanning Microscopy (CLSM) were undertaken to support the HPLC results and provide information concerning the overall stability of the Pheroid™ delivery system. After the completion of the above analyses, experiments were carried out to determine whether adjustments to some of the key chromatographic parameters could improve the separation of Pheroid™-based samples. The parameters that were subjected to change included the organic solvent, isocratic versus gradient separation, pH and detection wavelength. Two pro-Pheroid vesicles formulations were prepared and stored for a three month period at 40°C+75%RH only. No API was added to the one formulation while the other contained 2 mg/ml of mefloquine hydrochloride. Results obtained indicated that the Pheroid™ formulations changed after exposure to elevated temperature and humidity. The number of detectable peaks increased, longer run times became necessary and solubility in the sample solvent (methanol) decreased. Solubility of the Pheroid™ formulations in methanol was preserved to some extent by the presence of TBHQ. Physical signs of instability like discolouration and creaming were noted for TBHQ-containing formulations. TBHQ also seemed to have influenced the particle sizes, particle size distributions and structure of the Pheroid™ microsponges. With adjustments made to the HPLC method it was found that: i. the sample solvent is incompatible with the HPLC system, ii. very hydrophobic compounds are present in the Pheroid™-based samples, iii. acetontrile and methanol are unsuitable for both gradient and isocratic separation of Pheroid™-based samples, iv. more Pheroid™ components absorb at shorter wavelengths, and v. small changes in the pH values usually implemented do not influence the retention and selectivity of the Pheroid™ components. The Pheroid™ delivery system proved to be too complex and reversed hydrophobic for phase HPLC analysis. Preparation of the sample by only diluting the Pheroid™ formulations with pure methanol was not optimal. These samples introduced compounds to the column of which some caused interferences with the analyte peak while others were difficult to elute from the column. To continue using HPLC for the analysis of Pheroid™-based drug products, it is therefore recommended that attention should be given to the development of a more appropriate sample preparation procedure, like solid phase extraction or liquid-liquid extraction, one that will eliminate the effects of the Pheroid™ components. Physical instabilities noticed with the addition of TBHQ, suggest that there should also be attended to the compatibility and stability of each of the components in the Pheroid™ delivery system during formulation development. Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

Made available in DSpace on 2013-08-28T14:09:48Z (GMT). No. of bitstreams: 1 WOS000268831200019.pdf: 455433 bytes, checksum: 74b4a366827f83d1a3b3db22103227ea (MD5) Made available in DSpace on 2013-09-30T18:47:39Z (GMT). No. of bitstreams: 2 WOS000268831200019.pdf: 455433 bytes, checksum: 74b4a366827f83d1a3b3db22103227ea (MD5) WOS000268831200019.pdf.txt: 23436 bytes, checksum: 6dab3bf68ed45c4689a5b8a1286873f7 (MD5) Previous issue date: 2009-06-17 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:56:31Z No. of bitstreams: 2 WOS000268831200019.pdf: 455433 bytes, checksum: 74b4a366827f83d1a3b3db22103227ea (MD5) WOS000268831200019.pdf.txt: 23436 bytes, checksum: 6dab3bf68ed45c4689a5b8a1286873f7 (MD5) Made available in DSpace on 2014-05-20T13:56:31Z (GMT). No. of bitstreams: 2 WOS000268831200019.pdf: 455433 bytes, checksum: 74b4a366827f83d1a3b3db22103227ea (MD5) WOS000268831200019.pdf.txt: 23436 bytes, checksum: 6dab3bf68ed45c4689a5b8a1286873f7 (MD5) Previous issue date: 2009-06-17 Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP) Gas Natural e Biocombustiveis (ANP) This work is aimed to assess the aerobic biodegradation of biodiesel/diesel blends (0, 2, 5, 20 and 100%, v/v) by Candida viswanathii. The biodegradation potential of the inoculum was assessed with the redox indicator 2,6-dichlorophenol indophenol (DCPIP) test and with respirometric experiment in biometer flasks (250 mL) used to measure the microbial CO(2) production. In the latter, the inoculum was added to a contaminated soil with the blends (addition of 50 mL of fuel/Kg of soil from a non-contaminated site). C. viswanathii was able to increase significantly (approximately 50% in terms of CO(2) production) the biodegradation in soil of biodiesel/diesel blends and neat biodiesel since it preferable biodegrades biodiesel. Without inoculum the biodegradation of diesel oil was higher than biodiesel and blends (47.3, 51.1, 5.7 and 22.1% in terms of CO(2) production by B2, B5, B20 and B100, respectively) presumably due to the presence of the antioxidant terc-butyl-hydroquinone (TBHQ) in the biodiesel. São Paulo State Univ, UNESP, Inst Biosci, Dept Biochem & Microbiol, BR-13506900 Rio Claro, SP, Brazil São Paulo State Univ, UNESP, Inst Biosci, Dept Biochem & Microbiol, BR-13506900 Rio Claro, SP, Brazil ANP: PRH-05

Endogenously expressed human canonical transient receptor potential 1 (hTRPC1) and human canonical transient receptor potential 6 (hTRPC6) have been shown to play a role in store-operated Ca2+ entry (SOCE) in human platelets, where two mechanisms for SOCE, regulated by the dense tubular system (DTS) or the acidic granules, have been identified. In cells preincubated for 1 min with 100 µM flufenamic acid we show that hTRPC6 is involved in SOCE activated by both mechanisms, as demonstrated by selective depletion of the DTS or the acidic stores, using thapsigargin (TG) (10 nM) or 2,5-di-(tert-butyl)-1,4-hydroquinone (TBHQ) (20 µM), respectively, although it is more relevant after acidic store depletion. Co-immunoprecipitation experiments indicated that depletion of both stores separately results in time-dependent interaction between hTRPC1 and hTRPC6, and also between both hTRPCs and the type II IP3 receptor (IP3RII). The latter was greater after treatment with TG. TBHQ-induced coupling between hTRPC1 and 6 was transient and decreased after 30s of treatment, while that induced by TG increased for at least 3 min. TBHQ induced association between SERCA3, located in the acidic stores, hTRPC1, hTRPC6 and Orai1. TBHQ also evoked coupling between SERCA3 and IP3RII, presumably located in the DTS, thus suggesting interplay between both Ca2+ stores. Similarly, TG induces the interaction of SERCA2b with hTRPC1 and 6 and the IP3RII. The interactions between hTRPC1, hTRPC6, IP3RII and SERCA3 were impaired by disruption of the microtubules, supporting a role for microtubules in Ca2+ homeostasis. In conclusion, the present data demonstrate for the first time that hTRPC1, hTRPC6, IP3RII and SERCA3 are parts of a macromolecular protein complex activated by depletion of the intracellular Ca2+ stores in human platelets.

Corn oil obtained from a Brazilian industry, free from antioxidants and citric acid, added of different tertiary butylhydroquinone (TBHQ) concentrations, was submitted to accelerated oxidation in the Schaal oven test at 63°C for 120 hours and for 168 hours in a photooxidation chamber. Peroxide and absorptivity values at 232nm and 270nm were determined for this oil. From the Schaal oven test results, the best and the economical TBHQ doses were determined to this oil. Afterwards, a shelf life experiment was conducted and confirmed 115mg.kg-1 TBHQ as the best and economical dose for that oil. Óleo de milho obtido de uma indústria brasileira isento de antioxidantes e de ácido cítrico foi adicionado de diferentes concentrações de TBHQ e submetido a testes acelerados de oxidação em estufa a 63(0)C por 120 horas e em câmara de fotoxidação por 168 horas. Foram analisados o índice de peróxido e as absortividades em 232nm e 270nm deste óleo. A partir dos resultados do teste em estufa, calculou-se a melhor dose e a dose econômica do antioxidante TBHQ. Em seguida foi conduzido, então ensaio ao ambiente, que confirmou a concentração de 115mg.kg-1 TBHQ como a dosagem econômica e melhor dose para o óleo sob estudo.

The SERCA family includes 3 genes (SERCA1-3), each of which giving rise to various isoforms. To date, detailed structural data is only available for the SERCA1a isoform. Here, limited trypsinolysis of either human platelet membranes or recombinant SERCA3a in HEK-293 cells followed by Western blotting using antibodies covering different regions of the SERCA3(a) protein revealed two, kinetically distinct, Early (ETF) and Late (LTF) Tryptic Fragmentations. The ETF uses many tryptic sites while the LTF uses a unique tryptic site. Using site-directed mutagenesis: i) Arg(334), Arg(396) and Arg(638) were directly assigned to the ETF and ii) Arg(198) was assigned as the only tryptic site to the LTF. Arg(671), Lys(712)/Lys(713) and Lys(728) were also found to modulate the ETF. SERCA inhibitors Tg and tBHQ induced modest inhibition of the ETF. In contrast, the addition of CaCl(2), EGTA or AlF(4)(-) strikingly modified the ETF without any effect on the LTF. Trypsinolysis of the other recombinant SERCA3b-3f isoforms revealed: i) same ETF and LTF as SERCA3a, with variations of the length of the C-terminal fragments; ii) Arg(1002) as an additional tryptic site in SERCA3b-3e isoforms. Taken together, the two distinct SERCA3 fragmentation profiles sign the co-expression of SERCA3 proteins in two conformational states in cell membranes.