benzoic acid

苯甲酸
  • 文章类型: Journal Article
    目的是研究日粮苯甲酸(BA)对氮(N)平衡的影响,尿液pH值,浆液pH值,猪的粪便和泥浆中的气味化合物。
    将12只初始体重为56.2±2.6kg的手推车单独安置在代谢板条箱中。这些动物被分配到一个重复的6×4不完整的拉丁正方形设计中,有12只动物,6实验饮食,和4个时期,导致每个治疗8个观察结果。基础饮食主要是玉米,豆粕,和菜籽粉。在基础日粮中添加0.5%的苯甲酸,1.0%,1.5%,2.0%,或以玉米淀粉为代价的2.5%BA。每个周期包括4天的适应期和24小时的泥浆收集期,接下来是4天的粪便和尿液收集期。在第5天,收集粪便和尿液24小时并混合以获得浆液样品。
    每日消化的N随着BA补充的增加而线性增加(p<0.05)。补充BA以线性和二次方式降低尿pH(p<0.001)和浆液pH(p<0.05)。在粪便样本中,乙酸盐的浓度,丙酸盐,丁酸盐,添加BA后,粪臭素线性下降(p<0.05)。在泥浆样品中,丁酸的浓度,异戊酸,通过补充BA,粪臭素线性下降(p<0.05)。
    总而言之,补充苯甲酸有可能以剂量依赖性方式改善猪的氮消化。此外,膳食苯甲酸降低尿pH值,浆液pH值,以及猪粪便和泥浆中气味化合物的浓度。
    UNASSIGNED: The objective was to investigate the effects of dietary benzoic acid (BA) on nitrogen (N) balance, urinary pH, slurry pH, and odorous compounds in feces and slurry of pigs.
    UNASSIGNED: Twelve barrows with an initial body weight of 56.2±2.6 kg were individually housed in metabolism crates. The animals were allocated to a replicated 6×4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods, resulting in 8 observations per treatment. The basal diet consisted mainly of corn, soybean meal, and rapeseed meal. Benzoic acid was supplemented to the basal diet at 0.5%, 1.0%, 1.5%, 2.0%, or 2.5% BA at the expense of corn starch. Each period consisted of a 4-day adaptation period and a 24-hour collection period for slurry, followed by a 4-day collection period for feces and urine. On day 5, feces and urine were collected for 24 hours and mixed to obtain slurry samples.
    UNASSIGNED: The daily digested N linearly increased (p<0.05) with increasing BA supplementation. Supplemental BA lowered urinary pH (p<0.001) and slurry pH (p<0.05) in a linear and quadratic manner. In the fecal samples, the concentrations of acetate, propionate, butyrate, and skatole linearly decreased (p<0.05) with supplemental BA. In the slurry samples, the concentrations of butyrate, isovalerate, and skatole linearly decreased (p<0.05) by supplemental BA.
    UNASSIGNED: In conclusion, supplemental benzoic acid has the potential to improve nitrogen digestion in a dose-dependent manner for pigs. Additionally, dietary benzoic acid lowers urinary pH, slurry pH, and concentrations of odorous compounds in pig feces and slurry.
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  • 文章类型: Journal Article
    这篇综述的目的是研究苯甲酸如何减轻断奶压力的负面影响,改善肠道微生物群,肠道健康,和保育猪的生长,确定最佳剂量水平的苯甲酸生长速率在保育猪,并比较苯甲酸和其他酸在猪饲料中的功效。断奶后,猪在很少的时间间隔内接触较少的乳糖和具有高酸结合能力的固体饲料,导致消化液的pH值增加,减少蛋白质消化,增加胃中产氨的细菌。补充苯甲酸通过其抗微生物特性和降低消化液中的pH值改善了保育猪的肠道健康和生长。苯甲酸对猪小肠内腔微生物群的正向调节改善了肠道形态,提高了营养利用率,尤其是氮,苗圃的猪。饲料中添加高达1%的苯甲酸也会增加保育猪尿液中的马尿酸含量,降低尿液pH值,这与集约化养猪生产中的氨排放和谷仓条件有关。在苯甲酸的有益影响的支持下,保育猪的生长性能也得到了改善。然而,饲料中过量的苯甲酸(超过2.5%至5%)会降低保育猪的生长性能。因此,这篇综述对16篇论文的结果进行了荟萃分析,以确定苯甲酸对保育猪体重增加的最佳剂量水平,被发现是0.60%。苯甲酸的功效与其他有机酸相似,包括柠檬酸,富马酸,甲酸,和甲酸盐。总的来说,补充苯甲酸可以积极调节小肠的管腔和粘膜微生物群,增加营养利用率和肠道健康,降低尿液pH值,提高保育猪的生长性能。
    The objectives of this review are to investigate how benzoic acid can mitigate the negative effects of weaning stress, improve the intestinal microbiota, intestinal health, and growth of nursery pigs, determine the optimal dose level of benzoic acid for the growth rate in nursery pigs, and compare the efficacy of benzoic acid and other acids in pig feeds. After weaning, pigs are exposed to less lactose and solid feed with high acid-binding capacity at infrequent intervals, causing an increase in digesta pH, reducing protein digestion, and increasing ammonia-producing bacteria in the stomach. Benzoic acid supplementation has improved the intestinal health and growth of nursery pigs through its antimicrobial properties and pH reduction in the digesta. The positive modulation of luminal microbiota in the small intestine of pigs by benzoic acid improves intestinal morphology and enhances nutrient utilization, especially nitrogen, of nursery pigs. Benzoic acid supplementation of up to 1% in feeds also increases hippuric acid contents in the urine of nursery pigs, decreasing urinary pH, which is related to ammonia emission and barn conditions in intensive pig production. Supported by the beneficial impacts of benzoic acid, the growth performance of nursery pigs was also improved. However, excessive benzoic acid (over 2.5% up to 5%) in feeds reduces the growth performance of nursery pigs. Thus, this review conducted a meta-analysis of the results from 16 papers to determine the optimal dose level of benzoic acid for body weight gain of nursery pigs, which was found to be 0.60%. The efficacy of benzoic acid was similar to that of other organic acids, including citric acid, fumaric acid, formic acid, and formate salts. Collectively, benzoic acid supplementation can positively modulate the luminal and mucosal microbiota in the small intestine, increase nutrient utilization and intestinal health, decrease urinary pH, and improve the growth performance of nursery pigs.
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  • 文章类型: Journal Article
    革兰氏阴性菌大肠杆菌Nissle1917(EcN)在治疗各种肠道疾病方面的治疗潜力早已得到认可。细菌鬼魂(BG)是无生命细菌细胞的空壳,显示出巨大的医学应用潜力。遗传和化学技术可以创建这些BG。在目前的研究中,我们首次使用苯甲酸(BA)和氢氧化钠(SH)生产了大肠杆菌Nissle1917幽灵(EcNG)。BA是一种微弱的酸性化学物质,可增强革兰氏阴性菌的外膜通透性,减少能源生产,降低内部pH值。SH已显示出从一些革兰氏阴性和革兰氏阳性生物体中产生BG的成功。本研究旨在使用SH和BA的最小抑制浓度(MIC)生产EcNG,具体为3.125mg/mL。我们使用定量PCR(qPCR)和Bradford蛋白测定来评估产生的BG的细菌质量。场发射扫描电子显微镜(FE-SEM)显示了EcNG的三维结构。该研究证实了外表面存在隧道状孔隙,表明细胞膜完整性的保存。重要的是,这项研究介绍了BA作为一种新型的EcNGs化学诱导剂,表明其与SH一起有效形成EcNG的潜力。
    The gram-negative bacterium Escherichia coli Nissle 1917 (EcN) has long been recognized for its therapeutic potential in treating various intestinal diseases. Bacterial ghosts (BGs) are empty shells of non-living bacterial cells that demonstrate enormous potential for medicinal applications. Genetic and chemical techniques can create these BGs. In the current study, we produced Escherichia coli Nissle 1917 ghosts (EcNGs) for the first time using benzoic acid (BA) and sodium hydroxide (SH). BA is a feeble acidic chemical that enhances gram-negative bacteria\'s external membrane permeability, reduces energy production, and decreases internal pH. SH has shown success in producing BGs from some gram-negative and gram-positive organisms. This research aims to produce EcNGs using the minimum inhibitory concentration (MIC) of SH and BA, specifically 3.125 mg/mL. We assessed the bacterial quality of the BGs produced using quantitative PCR (qPCR) and Bradford protein assays. Field emission scanning electron microscopy (FE-SEM) showed the three-dimensional structure of EcNGs. The study confirmed the presence of tunnel-like pores on the outer surface, indicating the preservation of cell membrane integrity. Importantly, this investigation introduces BA as a novel chemical inducer of EcNGs, suggesting its potential alongside SH for efficient EcNG formation.
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  • 文章类型: Journal Article
    由于高度可压缩的超临界流体介质中的多方向温度效应,超临界流体固有了各种交叉现象。溶解度交叉,即温度对不同压力下溶解度的有争议的影响,可能是其中最知名的。对于不同固定相的几种非极性化合物,出乎意料地观察到在超临界二氧化碳中的溶解度与在以纯CO2为洗脱剂的超临界流体色谱中的保留率之间的上交叉压力值存在奇怪的差异。在某些情况下,发现保留交叉发生在几乎两倍于相同化合物的溶解度交叉压力的压力下。具有已知溶解度交叉的三种溶质的保留数据:蒽,苯甲酸和香兰素,在不同的压力和温度下收集几个固定相。上部保留交叉的存在,即这样的压力值,超过该压力值,温度增加开始减少保留,对所有溶质-吸附剂组合进行了登记。使用已知的温度对超临界流体色谱中的保留和对超临界二氧化碳中的溶解度的影响的热力学模型,讨论了观察到的差异的可能推理。假设吸附和分区保留机制之间的平衡对定义保留交叉值的主要贡献。
    Various crossover phenomena are immanent to supercritical fluids due to multidirectional temperature effects in highly compressible supercritical fluid media. Solubility crossover, i.e. controversial effect of temperature on solubility at different pressures, is probably the most well-known among them. A curious discrepancy in upper crossover pressure values between solubility in supercritical carbon dioxide and retention in supercritical fluid chromatography with pure CO2 as an eluent was unexpectedly observed for several non-polar compounds on different stationary phases. In some cases, retention crossover was found to happen at pressures almost twice as high as pressures for solubility crossover for the same compound. Retention data for three solutes with known solubility crossovers: anthracene, benzoic acid and vanillin, were collected at different pressures and temperatures for several stationary phases. The existence of upper retention crossovers, i.e. such pressure values beyond which temperature increase starts decreasing retention, were registered for all solute-sorbent combinations. Using known thermodynamic models of temperature effect on retention in supercritical fluid chromatography and on solubility in supercritical carbon dioxide, possible reasoning for the observed discrepancies is discussed. Major contribution of the balance between adsorption and partition retention mechanisms in defining retention crossover values is hypothesized.
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  • 文章类型: English Abstract
    烟草香料广泛用于传统烟草产品中,电子尼古丁,加热烟草制品,还有鼻烟.为了抑制高水分含量引起的真菌生长,防腐剂,如苯甲酸(BA),山梨酸(SA),和对羟基苯甲酸酯经常掺入烟草香料中。尽管如此,食用超过安全阈值的防腐剂可能会带来健康风险。因此,这些防腐剂的分析测定对于质量保证和消费者保护至关重要。例如,BA和SA可在易感个体中引起不良反应,包括哮喘,荨麻疹,代谢性酸中毒,和抽搐。对羟基苯甲酸酯,因为它们的内分泌活动,被归类为内分泌干扰化学物质。尽管进行了广泛的研究,同时定量痕量亲水性(BA和SA)和疏水性(对羟基苯甲酸甲酯,对羟基苯甲酸乙酯,对羟基苯甲酸异丙酯,对羟基苯甲酸丙酯,对羟基苯甲酸丁酯,对羟基苯甲酸异丁酯,和对羟基苯甲酸苄酯)防腐剂在烟草香料中仍然具有挑战性。传统的液相萃取与高效液相色谱(HPLC)联用通常会导致高的假阳性率和灵敏度不足。相比之下,串联质谱提供了高灵敏度和特异性;然而,它的广泛应用受到费力的样品制备和巨大的运营成本的限制。因此,建立一种快速、灵敏的烟用香精中9种防腐剂的样品前处理和分析方法至关重要。在这项研究中,同时测定九种防腐剂(SA,基于三相中空纤维液相微萃取(3P-HF-LPME)技术结合HPLC,建立了烟草香精中的BA和7种对羟基苯甲酸酯)。为了获得最佳的预处理条件,萃取溶剂类型,样品相pH值,受体相pH,样品相体积,提取时间,氯化钠的质量分数,进行了检查。此外,HPLC参数,包括紫外检测波长和流动相组成,是精致的。最佳提取条件为:以二己醚为提取溶剂,15mL样品溶液(pH4)用作样品相,氢氧化钠水溶液(pH12)用作受体相,并在800r/min下进行30min的提取。色谱分离是使用AgilentPoroshell120EC-C18柱(100mm×3mm,2.7μm)和包含甲醇的流动相,0.02mol/L乙酸铵水溶液(含0.5%乙酸),和乙腈进行梯度洗脱。在优化条件下,九种目标分析物在各自的线性范围内表现出良好的线性关系,相关系数(r)≥0.9967,检测限(LODs)和定量限(LOQs)分别为0.02-0.07mg/kg和0.08-0.24mg/kg,分别。在两个峰值水平下,9种目标分析物的富集因子(EF)和提取回收率(ERs)分别为30.6-91.1和6.1%-18.2%,分别。9种目标分析物的回收率范围为82.2%至115.7%,相对标准偏差(RSD)(n=5)小于14.5%,中等和高水平。开发的方法很简单,精确,敏感,非常适合于烟用香精样品中防腐剂的快速筛选。
    Tobacco flavors are extensively utilized in traditional tobacco products, electronic nicotine, heated tobacco products, and snuff. To inhibit fungal growth arising from high moisture content, preservatives such as benzoic acid (BA), sorbic acid (SA), and parabens are often incorporated into tobacco flavors. Nonetheless, consuming preservatives beyond safety thresholds may pose health risks. Therefore, analytical determination of these preservatives is crucial for both quality assurance and consumer protection. For example, BA and SA can induce adverse reactions in susceptible individuals, including asthma, urticaria, metabolic acidosis, and convulsions. Parabens, because of their endocrine activity, are classified as endocrine-disrupting chemicals. Despite extensive research, the concurrent quantification of trace-level hydrophilic (BA and SA) and hydrophobic (methylparaben, ethylparaben, isopropylparaben, propylparaben, butylparaben, isobutylparaben, and benzylparaben) preservatives in tobacco flavors remains challenging. Traditional liquid phase extraction coupled with high performance liquid chromatography (HPLC) often results in high false positive rates and inadequate sensitivity. In contrast, tandem mass spectrometry offers high sensitivity and specificity; however, its widespread application is limited by laborious sample preparation and significant operational costs. Therefore, it is crucial to establish a fast and sensitive sample pretreatment and analysis method for the nine preservatives in tobacco flavors. In this study, a method for the simultaneous determination of the nine preservatives (SA, BA and seven parabens) in tobacco flavor was established based on three phase-hollow fiber-liquid phase microextraction (3P-HF-LPME) technology combined with HPLC. To obtain the optimal pretreatment conditions, extraction solvent type, sample phase pH, acceptor phase pH, sample phase volume, extraction time, and mass fraction of sodium chloride, were examined. Additionally, the HPLC parameters, including UV detection wavelength and mobile phase composition, were refined. The optimal extraction conditions were as follows: dihexyl ether was used as extraction solvent, 15 mL sample solution (pH 4) was used as sample phase, sodium hydroxide aqueous solution (pH 12) was used as acceptor phase, and the extraction was carried out at 800 r/min for 30 min. Chromatographic separation was accomplished using an Agilent Poroshell 120 EC-C18 column (100 mm×3 mm, 2.7 μm) and a mobile phase comprising methanol, 0.02 mol/L ammonium acetate aqueous solution (containing 0.5% acetic acid), and acetonitrile for gradient elution. Under the optimized conditions, the nine target analytes showed good linear relationships in their respective linear ranges, the correlation coefficients (r) were ≥0.9967, limits of detection (LODs) and quantification (LOQs) were 0.02-0.07 mg/kg and 0.08-0.24 mg/kg, respectively. Under two spiked levels, the enrichment factors (EFs) and extraction recoveries (ERs) of the nine target analytes were 30.6-91.1 and 6.1%-18.2%, respectively. The recoveries of the nine target analytes ranged from 82.2% to 115.7% and the relative standard deviations (RSDs) (n=5) were less than 14.5% at low, medium and high levels. The developed method is straightforward, precise, sensitive, and well-suited for the rapid screening of preservatives in tobacco flavor samples.
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  • 文章类型: Journal Article
    在这项研究中,旨在研究番茄酱中苯甲酸(BA)和山梨酸(SoA)的浓度,胡椒酱,番茄酱,蛋黄酱,和烧烤酱样品通过经过验证的静态顶空气相色谱-质谱(GC-MS)方法。使用水杨酸(SalA)作为内标,在BA和SoA的宽线性浓度范围内分别为2.5-5000和12.5-5000进行测量。BA和SoA的检测限(LODs)确定为1.5和4.5mg/kg,而定量限(LOQs)为2.5和12.5mg/kg,分别。在开放的番茄酱样品中,BA和SoA的平均回收率为98.5%和98.7%,而蛋黄酱样品中的平均回收率为98.7%和100.3%。分别。所提出的方法的准确性通过统计(显著性测试)评估优异的恢复值得到证实。在真实样本中,虽然罐装番茄酱和工业酱样品的结果被发现是合适的,BA和SoA是在一些以传统或自制名称出售的番茄和胡椒酱产品中确定的,尽管禁止在糊剂中使用防腐剂。防止糊状物中的掺假对公共卫生至关重要,这对于土耳其美食以及世界上普遍消费都是必不可少的。因此,由于其可靠性和毒性更低的化学试剂的消耗,该方法可用于食品控制实验室。
    In this study, it was aimed at investigating benzoic acid (BA) and sorbic acid (SoA) concentrations in tomato paste, pepper paste, ketchup, mayonnaise, and barbeque sauce samples by a validated static headspace gas chromatography-mass spectrometry (GC-MS) method. Salicylic acid (SalA) was used as internal standard and the measurements were conducted in the wide linear concentration ranges of BA and SoA which were 2.5-5000 and 12.5-5000, respectively. The limit of detections (LODs) were determined to be 1.5 and 4.5 mg/kg while the limit of quantifications (LOQs) were 2.5 and 12.5 mg/kg for BA and SoA, respectively. The average recovery% values of BA and SoA were found to be 98.5% and 98.7% in an open tomato paste sample while these values were 98.7% and 100.3% in a mayonnaise sample, respectively. Accuracy of the proposed method was confirmed by statistically (significance test) evaluating excellent recovery values. In real samples, while the results of the canned tomato pastes and industrial sauce samples were found suitable, BA and SoA ​​were determined in some tomato and pepper paste products sold under the traditional or homemade name although use of the preservatives in the pastes were prohibited. It is vital for public health to prevent adulteration in pastes which is indispensable for Turkish cuisine as well as prevalently consumed in the world. Therefore, the proposed method can be used in food control laboratories due to its reliability and consumption of much less toxic chemical reagents.
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  • 文章类型: Journal Article
    这项工作提供了对活性炭上水溶液中中性和离子形式的有机吸附物吸附的全面研究。pH对亚甲基蓝(MB)和有机酸吸附平衡和动力学的影响,苯甲酸(BA),2-硝基苯甲酸(2-NBA),3-硝基苯甲酸(3-NBA),和4-硝基苯甲酸(4-NBA),被调查。实验吸附等温线使用广义Langmuir等温线方程(R2=0.932-0.995)进行分析。使用多个吸附动力学方程研究了吸附速率数据,其中多指数方程给出了最佳拟合质量(R2-1=(6.3×10-6)-(2.1×10-3))。半衰期也用于表示pH对吸附动力学的影响。证明了吸附效率对溶液pH的强烈依赖性。在有机酸吸附的情况下,此过程的数量和速率随pH的降低而增加。此外,在相对较短的时间内,在碱性环境中记录了较多的亚甲基蓝吸附量。最大吸收量为11.59mmol/g,6.57mmol/g,9.38mmol/g,2.70mmol/g,BA为0.24mmol/g,2NBA,3-NBA,4-NBA,MB。使用热分析和X射线光电子能谱研究了纯活性炭和吸附后的选定样品。
    This work presents comprehensive studies of the adsorption of neutral and ionic forms of organic adsorbates from aqueous solutions on activated carbon. The influence of pH on the equilibrium and kinetics of the adsorption of methylene blue (MB) and organic acids, benzoic (BA), 2-nitrobenzoic (2-NBA), 3-nitrobenzoic (3-NBA), and 4-nitrobenzoic (4-NBA) acid, was investigated. Experimental adsorption isotherms were analyzed using the generalized Langmuir isotherm equation (R2 = 0.932-0.995). Adsorption rate data were studied using multiple adsorption kinetics equations, of which the multi-exponential equation gave the best fit quality (R2 - 1 = (6.3 × 10-6)-(2.1 × 10-3)). The half-time was also used to represent the effect of pH on adsorption kinetics. Strong dependences of the adsorption efficiency on the solution pH were demonstrated. In the case of organic acid adsorption, the amount and rate of this process increased with a decrease in pH. Moreover, larger adsorbed amounts of methylene blue were recorded in an alkaline environment in a relatively short time. The maximum absorbed amounts were 11.59 mmol/g, 6.57 mmol/g, 9.38 mmol/g, 2.70 mmol/g, and 0.24 mmol/g for BA, 2NBA, 3-NBA, 4-NBA, and MB. The pure activated carbon and the selected samples after adsorption were investigated using thermal analysis and X-ray photoelectron spectroscopy.
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  • 文章类型: Journal Article
    缩醛的光诱导区域选择性HAT反应,醚,和在两分子光氧化还原系统中使用苯甲酸的醇导致在温和条件下与烯烃形成新的C-C键。两分子光氧化还原系统中苯甲酸产生的芳基羧基可以用作催化HAT试剂,即使需要过量的氢供体基底。各种缩醛,醚,酒精,和烯烃可用于光反应以提供高收率的加合物和高回收率的苯甲酸。
    The photoinduced regioselective HAT reactions of acetals, ethers, and alcohols using benzoic acids in a two-molecule photoredox system led to the formation of new C-C bonds with alkenes under mild conditions. Aryl carboxy radicals generated from benzoic acids in a two-molecule photoredox system can function as catalytic HAT reagents, even though an excess amount of a hydrogen donor substrate is required. Various acetals, ethers, alcohols, and alkenes can be employed in the photoreaction to provide both high yields of adducts and high recoveries of benzoic acids.
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  • 文章类型: Journal Article
    糖基转移酶催化糖苷基团向宽范围的受体化合物的转移,以产生具有多种生物和药理学活性的糖缀合物。本工作报告了烟草UGT89A2糖基转移酶(NtUGT89A2)的鉴定和生化特性。该酶是溶液中的单体,可催化苯甲酸的二羟基和三羟基化和氯化衍生物的O-β-糖基化。与2,3-二羟基苯甲酸(2,3-DHBA)和2,4-二羟基苯甲酸(2,4-DHBA)相比,NtUGT89A2优选2,5-二羟基苯甲酸(2,5-DHBA)。NtUGT89A2可使用的其它底物包括3,4,5-三羟基苯甲酸和氯化衍生物如2-氯-5-羟基苯甲酸(2-Cl-5-HBA)。通过热稳定性实验鉴定了NtUGT89A2的底物,其中我们观察到在2,5-DHBA和UDP-葡萄糖存在下10°C的热变性中点(Tm)的最大增加。另一方面,2,5-DHBA的比活性最高(225±1.7nkat/mg)。进一步的表征表明,该酶对其底物具有微摩尔亲和力。值得注意的是,该酶在70°C孵育1小时后保持完全活性。这些结果为未来NtUGT89A2的功能和结构研究提供了基础。
    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 (Tm) 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.
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  • 文章类型: Journal Article
    依托考昔{ETR的三种1:1共晶形式的结构;系统名称:5-氯-2-(6-甲基吡啶-3-基)-3-[4-(甲基磺酰基)苯基]吡啶,合成了C18H15ClN2O2S},并通过单晶X射线衍射对其进行了表征;这些是依托考昔-苯甲酸(1/1),C18H15ClN2O2S·C7H6O2(ETR-Bz),依托考昔-4-氟苯甲酸(1/1),C18H15ClN2O2S·C7H5FO2(ETR-PFB),和依托考昔-4-硝基苯甲酸(1/1),C18H15ClN2O2S·C7H5NO4(ETR-PNB)。粉末X射线衍射和热差示扫描量热法-热重法(DSC-TG)技术也用于表征这些多组分体系。由于相应酸的影响,ETR显示不同的构象。此外,超分子基序的能量贡献已经通过稳定相互作用力的能量框架研究建立,并且与共晶的热稳定性一致。
    The structures of three 1:1 cocrystal forms of etoricoxib {ETR; systematic name: 5-chloro-2-(6-methylpyridin-3-yl)-3-[4-(methylsulfonyl)phenyl]pyridine, C18H15ClN2O2S} have been synthesized and characterized by single-crystal X-ray diffraction; these are etoricoxib-benzoic acid (1/1), C18H15ClN2O2S·C7H6O2 (ETR-Bz), etoricoxib-4-fluorobenzoic acid (1/1), C18H15ClN2O2S·C7H5FO2 (ETR-PFB), and etoricoxib-4-nitrobenzoic acid (1/1), C18H15ClN2O2S·C7H5NO4 (ETR-PNB). Powder X-ray diffraction and thermal differential scanning calorimetry-thermogravimetry (DSC-TG) techniques were also used to characterize these multicomponent systems. Due to the influence of the corresponding acids, ETR shows different conformations. Furthermore, the energetic contributions of the supramolecular motifs have been established by energy framework studies of the stabilizing interaction forces and are consistent with the thermal stability of the cocrystals.
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