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The purpose of the present study was to investigate the mechanism of action of our newly developed green sanitizer formulation comprising a natural phenolic compound, gallic acid (GA), strengthened by the Generally Recognized as Safe (GRAS) materials hydrogen peroxide (H2O2) and DL-lactic acid (LA). Combining 8 mM GA with 1 mM H2O2 resulted in an abundant generation of reactive oxygen species (ROS) and a bactericidal effect towards Gram-negative (Escherichia coli, Pseudomonas syringae, and Pectobacterium brasiliense) and Gram-positive (Bacillus subtilis) bacteria (4 to 8 log CFU mL−1 reduction). However, the exposure to this dual formulation (DF) caused only a modest 0.7 log CFU mL−1 reduction in the Gram-positive L. innocua population. Amending the DF with 20 mM LA to yield a triple formulation (TF) resulted in the efficient synergistic control of L. innocua proliferation without increasing ROS production. Despite the inability to grow on plates (>7 log CFU mL−1 population reduction), the TF-exposed L. innocua maintained high intracellular ATP pools and stable membrane integrity. The response of L. innocua to TF could be qualified as a "viable but nonculturable" (VBNC) phenomenon, while with the other species tested this formulation caused cell death. This research system may offer a platform for exploring the VBNC phenomenon, a critical food safety topic. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate the mechanism of action of our newly developed green sanitizer formulation comprising a natural phenolic compound, gallic acid (GA), strengthened by the Generally Recognized as Safe (GRAS) materials hydrogen peroxide (H2O2) and DL-lactic acid (LA). Combining 8 mM GA with 1 mM H2O2 resulted in an abundant generation of reactive oxygen species (ROS) and a bactericidal effect towards Gram-negative (Escherichia coli, Pseudomonas syringae, and Pectobacterium brasiliense) and Gram-positive (Bacillus subtilis) bacteria (4 to 8 log CFU mL−1 reduction). However, the exposure to this dual formulation (DF) caused only a modest 0.7 log CFU mL−1 reduction in the Gram-positive L. innocua population. Amending the DF with 20 mM LA to yield a triple formulation (TF) resulted in the efficient synergistic control of L. innocua proliferation without increasing ROS production. Despite the inability to grow on plates (>7 log CFU mL−1 population reduction), the TF-exposed L. innocua maintained high intracellular ATP pools and stable membrane integrity. The response of L. innocua to TF could be qualified as a “viable but nonculturable” (VBNC) phenomenon, while with the other species tested this formulation caused cell death. This research system may offer a platform for exploring the VBNC phenomenon, a critical food safety topic.

This study was conducted to evaluate the efficacy of a combination 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (i.e., Carvacrol and Thymol) at intake/dietary different levels on growth performance, intestinal health indicators, immune responses and fecal oocyst shedding in broiler chickens under Eimeria challenged condition. A total of 336 one-day-old broilers were randomly assigned to one of six dietary treatments with seven replications per treatment. Dietary treatments were: i) Non-challenged bird without any dietary treatment (NCNT), ii) Challenged bird without any dietary treatment (CNT), iii) Challenged birds fed a THB diet (0.1 g/kg, THB), iv) Challenged birds fed a combination of THB and oregano extracts diet (0.1 g/kg, COM 100), and a gradual increase of combination of THB and oregano extracts likely v) 0.15 g/kg (COM 150), and 0.2 g/kg (COM 200). On day 14, all groups except for NCNT have orally challenged with a 10-fold dose of Livacox® T anticoccidial vaccine to trigger coccidiosis. The results indicated that Eimeria-challenged broilers fed COM 100 and COM 200 diets increased (p < 0.05) body weight than CNT diet on day 35. Furthermore, birds fed COM 100 and COM 200 diets increased (p < 0.05) average daily gain compared to those fed CNT diets for the entire experimental period. There is no significant (p > 0.05) in average daily feed intake, feed efficiency between NCNT and birds fed with combined THB and oregano extracts for the entire experimental period. A combination of THB and oregano extract regardless of concentration levels or THB alone reduced (p < 0.05) lesion score in ileum compared to the CNT diet for 7 days post-infection (dpi). Birds fed COM 100 diet had lower (p < 0.05) intestinal lesion scores in jejunum and caeca on 7 dpi compared to those were in the CNT diet. No (p > 0.05) difference was observed in the oocysts per gram of feces count, intestinal morphology, carcass traits and blood cytokine concentration among the infected treatments. Collectively, we conclude that birds fed with a combination of THB and oregano extracts regardless of the ratios that were used demonstrated better recovery of health after the coccidial challenge than using only THB alone.

Glycosyltransferases catalyze the transfer of a glycoside group to a wide range of acceptor compounds to produce glycoconjugates with diverse biological and pharmacological activities. The present work reports the identification and biochemical characterization of Nicotiana tabacum UGT89A2 glycosyltransferase (NtUGT89A2). The enzyme is a monomer in solution that catalyzes the O - β -glucosylation of di- and tri-hydroxylated and chlorinated derivatives of benzoic acid. NtUGT89A2 has a preference for 2,5-dihydroxybenzoic acid (2,5-DHBA) over 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,4-dihydroxybenzoic acid (2,4-DHBA). Other substrates that can be used by NtUGT89A2 include 3,4,5-trihydroxybenzoic acid and chlorinated derivatives such as 2-chloro-5-hydroxybenzoic acid (2-Cl-5-HBA). The substrates of NtUGT89A2 were identified by thermal stability experiments, where we observed a maximum increase of the thermal denaturation midpoint (T m) of 10 °C in the presence of 2,5-DHBA and UDP-glucose. On the other hand, the highest specific activity was obtained with 2,5-DHBA (225 ± 1.7 nkat/mg). Further characterization revealed that the enzyme has a micromolar affinity for its substrates. Notably, the enzyme retains full activity after incubation at 70 °C for 1 h. These results provide a basis for future functional and structural studies of NtUGT89A2. The glycosyltransferase UGT89A2 from Nicotiana tabacum , expressed as a recombinant protein in Escherichia coli , catalyzes the O - β -glucosylation of di- and trihydroxylated derivatives of benzoic acid. [Display omitted] • UGT89A2 glycosyltransferase from Nicotiana tabacum was purified as a monomer by three-step liquid chromatography. • Thermal shift assay allowed identification of ligands and substrates. • NtUGT89A2 catalyzes the O - β -glucosylation of di- and tri-hydroxylated and chlorinated derivatives of benzoic acid. • NtUGT89A2 has a preference for 2,5-dihydroxybenzoic acid over 2,3-dihydroxybenzoic acid and 2,4-dihydroxybenzoic acid. • The enzyme has a micromolar affinity for 2,5-dihydroxybenzoic acid. • NtUGT89A2 remains fully active after incubation at 70 °C for 1 h. [ABSTRACT FROM AUTHOR]

Oxygen scavengers based on gallic acid (GA) usually contain a base that establishes the alkaline conditions necessary for the humidity-induced scavenger reaction. Here we measured the effect of sodium carbonate (Na2CO3) and sodium hydroxide (NaOH) on the reaction kinetics of such scavengers. The time-dependent oxygen absorption of aqueous GA solutions (pH 2.9–13.8) was determined and the results were described using a second-order kinetic model. We calculated the degree of deprotonation (DoD) of GA in the solutions from the species distribution curves, and assessed the effect of the DoD on the reaction kinetics. This revealed that both the reaction rate coefficient k and the scavenger capacity n were significantly affected by the DoD. If the DoD fell below 0.25, there was no significant reaction. Although k increased with the DoD, n reached a maximum at DoD = 0.6–0.7. In principle, target DoD values can be achieved using any base, but a strong base is more efficient because lower quantities are required. In our experiments, the amount of Na2CO3 required to reach the maximum DoD was more than twice that of NaOH. Our results provide the basis for the functional design of active packaging systems incorporating optimized GA-based oxygen scavengers.

Abstract: BACKGROUND: The present study demonstrates the decomposition of pentachlorophenol (PCP) by the Fenton reaction in the presence of gallic acid (GA). Unlike other studies, catalytic Fe2+ concentrations were used with respect to PCP in an effort to evaluate an environmentally benign Fenton system, studying the effect of phenolic‐type compounds widely found in the environment. The effect of operating variables was evaluated. RESULTS: At initial reaction times or at low H2O2 and Fe concentrations, GA enhanced PCP removal. At high H2O2 and Fe concentrations GA enhanced PCP removal only at initial reaction times. GA was the determinant factor controlling activity acting both as a chelating agent and reducer of Fe3+. Electron paramagnetic resonance (EPR) spectroscopy was applied to shed light on mechanistic aspects, verifying the interaction of GA with Fe ions. GA accelerated significantly the Fe3+/Fe2+ redox cycling. This enhanced the formation of hydroxyl radicals (HO·) as confirmed by in situ EPR spin trap experiments. A reaction mechanism was proposed including the redox cycle of GA quinoide forms. CONCLUSION: The operational variables of a GA modified Fenton system are provided and mechanistic steps are discussed including PCP degradation, GA/Fe interaction, Fe3+/Fe2+ redox cycling and HO· formation. GA concentration controls the catalytic degradation of PCP. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The premise was to adapt a conventional beef burgundy model for use in microwave cooking (MC) whilst preserving nutritional and eating qualities. The effects of specific power and different cooking times were measured by meat tenderness, Nε-carboxymethyllysine (CML), lysine, polyphenol contents and energy consumption. A CORICO (CORrelations ICOnography) design for four factors (specific power, times of browning, cooking and reduction) was used to compare MC and traditional cooking (TC) determining the optimized MC conditions. For the optimal conditions (specific power of 0.84 W/g and a cooking time of 84 min), the level of CML product was similar to that measured after TC. However, lysine degradation was more pronounced when TC was used compared to optimized MC. Consumer tests showed that the eating quality of the beef burgundy cooked using MC compared favourably to that of the TC. Energy consumption of the optimized MC conditions was lower than the conventional process (4.67 kWh vs 6.52 kWh) and the cooking time was decreased by 56% compared to TC. [ABSTRACT FROM AUTHOR]

Poly(aryl ether) dendrons ( 2) bearing long alkyl chains can undergo physical gelation in various organic solvents, especially alkanes and alcoholic solvents. In contrast, 3,4,5-trialkoxyphenyl derivatives ( 1), which are the building blocks of the dendrons ( 2), do not exhibit any gelation properties; thus, revealing the key role of the dendron structure in the aggregation/gelation process. Hansen solubility parameters allow us to gain a detailed understanding of the role of solvent in gelation. Critical gel concentrations, FT-IR spectroscopy, NMR spectroscopy, T measurements, and scanning electron microscopy are used to characterize the gel structures. [ABSTRACT FROM AUTHOR]

Abstract: B3LYP/6-31++G(d) method was used for the structural study of 3,4,5-trihydroxybenzoic acid (3,4,5-THBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), and 4-hydroxybenzoic acid (4-HBA). Calculated structures agree with available X-ray experimental data within 2%. The phenolic Ossociation enthalpy (BDE) of all sites in each benzoic acid were determined and compared with those of phenol (for 4-HBA) and catechol (for 3,4-DHBA). The consistency between the calculated values and experimental ones are within 5.4% and 9.2%, respectively, for 4-HBA and 3,4-DHBA. The reactions of benzoic acids with and OH radicals were studied and it turns out that benzoic acids react differently with both radicals. We have shown that the reaction of hydroxybenzoic acids with the hydroxyl radical was governed by a phenolic hydrogen (H+ +e−) transfer from the acid to the radical, while for the superoxide radical, the reaction is governed by a proton (H+) transfer from the acid to the radical. The first reaction is evidenced by the delocalization of the radical on the entire quinone moiety, and the second reaction is evidenced by the negative NBO charge on the phenoxide moiety as well as the localization of the radical on the hydroperoxy (O2H) moiety. [Copyright &y& Elsevier]

Abstract: A new technique of calculation of a distribution function of activation energy () of shear viscosity based on a regularization procedure applied to the Fredholm integral equation of the first kind has been developed using the Baxter-Drayton and Brady model for concentrated and flocculated suspensions. This technique has been applied to the rheological data obtained at different shear rates for aqueous suspensions with fumed silica A-300 and low-molecular (3,4,5-trihydroxybenzoic acid and 1,5-dioxynaphthalene) or high-molecular (poly(vinyl pyrrolidone) of 12.7 kDa and ossein of 20–29 kDa) compounds over a wide concentration range (up to 25 wt% of both components) and at different temperatures. Monomodal distributions are observed for the suspensions with individual A-300 or A-300 with a low amount of adsorbed organics. In the case of larger amounts of nanosilica and organics the distributions are multimodal because of stronger structurization and coagulation of the systems that require a high energy to break the coagulation structures resisting to the shear flow. [Copyright &y& Elsevier]

Five compounds, terephthalic acid mono-[2-(4-carboxy-phenoxycarbonyl)-vinyl] ester (1), (E)-3-(5′-hydroperoxy-2,2′-dihydroxy[1,1′-biphenyl]-4-yl)-2-propenoic acid (2), 3,4,5-trihydroxybenzoic acid (3), succinic acid (or butanedioic acid) (4), and 2,3,4,5,6-pentahydroxybenzoic acid (5), were isolated from Phyllanthus urinaria. The structures of these compounds were elucidated by means of spectral techniques including IR, MS, and 1D/2D NMR. 1 and 2 are new compounds. [ABSTRACT FROM AUTHOR]