Aldehyde

  • 文章类型: Journal Article
    在加工过程中,在海参粉中检测到40多种挥发性化合物(通过冷冻干燥,海水淡化,超临界流体萃取和超微研磨)通过包括电子鼻在内的多种方法,GC-IMS和GC-MS。已经确定醛是原始冻干样品中的主要挥发性物质,约占总挥发性物质的30%。此外,我们建立了一种超临界流体萃取策略,可以有效地去除海参粉末中的醛。GC-IMS和GC-MS表明醛的相对含量显著降低了14%和28%,分别。使用GC-MS定量醛显示辛醛从927μg/kg显著降低至159μg/kg。进一步的调查结合OAV分析显示,冻干海参粉中的17种挥发性物质被认为是主要的挥发性化合物(OAV>1)。在海参粉末中发现的主要鱼腥味化合物被鉴定为己醛,octanal,和使用GC-O的身份不明的化合物,通过我们建立的超临界流体萃取策略可以有效地去除(OAV无法估计)。
    More than 40 volatile compounds were detected in sea cucumber powder during the processing (through freeze-dried, desalination, supercritical fluid extraction and ultra-micro grinding) by multiple methods including e-nose, GC-IMS and GC-MS. It has been determined that aldehydes are the predominant volatile substances in the original freeze-dried sample, accounting for about 30 % of the total volatile substances. In addition, we established a supercritical fluid extraction strategy that could efficiently remove the aldehydes from the sea cucumber powder. GC-IMS and GC-MS showed that the relative content of aldehydes significantly decreased by 14 % and 28 %, respectively. Quantification of aldehydes using GC-MS showed a significant decrease in octanal from 927 µg/kg to 159 µg/kg. Further investigation combined with OAV analysis showed that 17 volatile substances in the freeze-dried sea cucumber powder were considered to be the predominant volatile compounds (OAV > 1).The primary fishy compounds found in sea cucumber powder were identified as hexanal, octanal, and an unidentified compound using GC-O, which can be effectively removed (OAV can\'t been estimated) by the supercritical fluid extraction strategy we established.
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  • 文章类型: Journal Article
    随着绿色化学在有机合成中的重要性日益增强,电化学氧化发展迅速。化合物在电极表面通过电子转移进行氧化还原反应。本文提出了使用电化学方法来实现苄基C-N键的断裂。该方法选择性地氧化裂解C-N键而不需要金属催化剂或外部氧化剂。此外,小学,次要,和叔胺在这些条件下表现出良好的适应性,利用水作为氧气的唯一来源。
    With the growing significance of green chemistry in organic synthesis, electrochemical oxidation has seen rapid development. Compounds undergo oxidation-reduction reactions through electron transfer at the electrode surface. This article proposes the use of electrochemical methods to achieve cleavage of the benzyl C-N bond. This method selectively oxidatively cleaves the C-N bond without the need for metal catalysts or external oxidants. Additionally, primary, secondary, and tertiary amines exhibit good adaptability under these conditions, utilizing water as the sole source of oxygen.
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  • 文章类型: Journal Article
    直到1990年代才建立了将羰基插入C(sp2)-Pd(II)σ键(Grignard型加成)。虽然自那时以来,这种元素反应已经得到了很好的探索,其在Pd(0)不对称催化中的应用仍然难以捉摸。在这里,我们报道了在HCO2H添加剂存在下,Pd(0)催化的乙烯基碘-羰基的不对称分子内格氏反应,提供具有良好至优异的对映选择性和非对映选择性的环状烯丙醇。机理研究表明,除了作为一种有效的还原剂,HCO2H还能够促进所涉及的仲烷氧基-Pd(II)的质子化,从而完全抑制β-H的消除。此外,在碘化乙烯醛和1-氘代醛的竞争反应中没有发现KIE,证明了醛插入的简便步骤。
    The insertion of carbonyl into C(sp2)-Pd(II) σ-bond (Grignard-type addition) was not established until the 1990s. While this elemental reaction has been well explored since then, its application in Pd(0) asymmetric catalysis remain elusive. Herein, we report the Pd(0)-catalyzed asymmetric intramolecular Grignard-type reaction of vinyl iodide-carbonyl in the presence of HCO2H additive, affording cyclic allylic alcohol with good to excellent enantioselectivity and diastereoselectivity. Mechanistic studies suggested that besides serving as an efficient reductant, HCO2H is also capable of facilitating protonation of the involved secondary alkoxyl-Pd(II), thus completely suppressing the β-H elimination. Moreover, no KIE was found in the competing reaction between vinyl iodide-aldehyde and 1-deuterated one, demonstrating the facile step of aldehyde insertion.
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  • 文章类型: Journal Article
    宝石-二溴烷烃是有机化学中重要的合成结构单元,但是他们的准备仍然很麻烦。在这里,我们已经开发了一种简单实用的方案,使用四丁基三溴化铵和亚磷酸三苯酯从醛合成宝石-二溴烷烃。各种烷基和芳香醛可以在10分钟内转化为相应的产物。该协议也适用于酒精,并且在此过程中手性醇的构型被反转,具有优异的对映体纯度。
    gem-Dibromoalkanes are important synthetic building block in organic chemistry, but their preparation is still troublesome. Herein, we have developed a simple and practical protocol for the synthesis of gem-dibromoalkanes from aldehydes using tetrabutylammonium tribromide and triphenyl phosphite. A variety of alkyl and aromatic aldehydes can be transformed into the corresponding products within 10 minutes. This protocol is also applicable to alcohols, and the configuration of chiral alcohol is inverted during the process with excellent enantiopurity.
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  • 文章类型: Journal Article
    聚甲醛二甲醚(PODE)和甲醇是重要的低碳替代燃料,可降低内燃机的碳排放。在研究中,甲醇比的影响,喷射正时,利用发动机试验和数值模拟研究了进气温度对HCHO生成和排放的影响。结果表明,甲醇比例的增加抑制了PODE的自燃趋势,导致点火延迟时间的增加,压力峰值,和气缸内的放热率峰值。缸内燃烧温度的降低有助于由于缸内和排气管中的甲醇的部分氧化而导致的HCHO排放的增加。当喷射正时从-10°CAATDC逐渐推迟到2°CAATDC时,缸内高温区域减少,未燃烧甲醇的数量增加,但是由于H自由基的影响,部分HCHO转化为HCO,导致HCHO排放增加72%。随着进气温度的升高,缸内甲醇的氧化和分解加速,导致燃烧稳定性的改善,更均匀的温度分布,减少未燃烧的甲醇,这导致较低的HCHO排放。当进气温度从30℃上升到60℃时,HCHO排放量减少11.2%。
    Polyoxymethylene dimethyl ether (PODE) and methanol are important low-carbon substitutable fuels for reducing carbon emissions in internal combustion engines. In the research, the impacts of methanol ratio, injection timing, and intake temperature on HCHO generation and emission were investigated using both engine tests and numerical simulations. Results suggest that an increase in methanol ratio suppresses auto-ignition tendency of PODE, leading to the increase of ignition delay period, pressure peak, and heat release rate peak inside the cylinder. The decrease in in-cylinder combustion temperature contributes to an increase in HCHO emission due to partial oxidation of methanol in the cylinder and exhaust pipe. While the injection timing is gradually postponed from -10 °CA ATDC to 2 °CA ATDC, in-cylinder high-temperature area decreases, the quantity of unburned methanol increases, but part of HCHO is converted to HCO due to H radical influence, resulting in 72% increased HCHO emission. With the increment of intake temperature, the oxidation and decomposition of in-cylinder methanol accelerate, leading to an improvement in combustion stability, more uniform temperature distribution, and a decrease in unburned methanol, which results in lower HCHO emission. When the intake temperature is rose from 30 to 60 °C, HCHO emission decreases by 11.2%.
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  • 文章类型: Journal Article
    碳水化合物代谢紊乱(CMD),比如糖尿病,半乳糖血症,和甘露多菌病,导致纤毛病样多器官缺陷。然而,纤毛与CMD并发症的机制联系仍然知之甚少.在这里,我们描述了用病理相关的醛糖而不是相应的糖醇治疗细胞时显著的纤毛分解。此外,环境醛能够通过其甲酰基的空间位阻效应触发纤毛分解。机制研究表明,醛刺激细胞外钙通过质膜流入,随后激活钙调蛋白-AuroraA-组蛋白脱乙酰酶6途径以使轴突微管脱乙酰并触发纤毛分解。体内实验进一步表明,Hdac6敲除小鼠对醛诱导的气管纤毛和精子鞭毛的分解具有抗性。这些发现揭示了甲酰基介导的纤毛分解在CMD并发症中的作用。
    Carbohydrate metabolism disorders (CMDs), such as diabetes, galactosemia, and mannosidosis, cause ciliopathy-like multiorgan defects. However, the mechanistic link of cilia to CMD complications is still poorly understood. Herein, we describe significant cilium disassembly upon treatment of cells with pathologically relevant aldoses rather than the corresponding sugar alcohols. Moreover, environmental aldehydes are able to trigger cilium disassembly by the steric hindrance effect of their formyl groups. Mechanistic studies reveal that aldehydes stimulate extracellular calcium influx across the plasma membrane, which subsequently activates the calmodulin-Aurora A-histone deacetylase 6 pathway to deacetylate axonemal microtubules and triggers cilium disassembly. In vivo experiments further show that Hdac6 knockout mice are resistant to aldehyde-induced disassembly of tracheal cilia and sperm flagella. These findings reveal a previously unrecognized role for formyl group-mediated cilium disassembly in the complications of CMDs.
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  • 文章类型: Journal Article
    通过光维素与四种醛的相互作用研究了鱼子酱贮藏过程中风味物质的释放机理。气相色谱-质谱联用表明光维素与3-甲基丁醛的结合率,非肛门,(E,Z)-2,6-壬烯醛,和(E)-2-辛烯醛随醛浓度的增加而降低。其中,(E,Z)-2,6-壬二烯醛(0.5mM)具有最高的结合率(84.47%)。(E,Z)-2,6-壬二烯醛与光维素是静态猝灭的,结合力包括自发的疏水相互作用。醛浓度的增加降低了光维素的α-螺旋含量,并导致光维素的微观结构聚集。分子对接结果表明,tyr残基对光素与醛的结合贡献最大。本研究阐明了鱼子酱蛋白对鱼子酱贮藏期间风味变化的影响机制,为鱼子酱贮藏期间风味的调控提供了有效的策略。
    The release mechanism of flavor during caviar storage was studied by the interaction between phosvitin and four aldehydes. Gas chromatography-mass spectrometry showed that the binding rate of phosvitin with 3-methylbutanal, nonanal, (E,Z)-2,6-nonadienal, and (E)-2-octenal decreased with an increase in the aldehyde concentrations. Among them, (E,Z)-2,6-Nonadienal (0.5 mM) had the highest binding rate (84.47%). The main quenching mechanism of (E,Z)-2,6-nonadienal with phosvitin was static quenching and the binding force comprised spontaneous hydrophobic interactions. An increase in the aldehyde concentrations reduced the α-helix content of phosvitin and led to aggregation of the microstructure of phosvitin. The results of molecular docking showed that tyr residue contributed the most to the binding of phosvitin to aldehydes. This study has elucidated the mechanism of the effect of caviar protein on changes in the caviar flavor during storage and provides effective strategies for regulation of caviar flavor during storage.
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  • 文章类型: Journal Article
    醛是公认的可能影响脂质代谢的环境毒物。例如,已经发现丙烯醛仅增加血清甘油三酯(TG)水平。然而,目前尚不清楚其他醛是否也与高甘油三酯血症(HTG)有关,以及可能涉及的机制。这项横断面研究分析了来自国家健康和营养调查(NHANES,2013-2014),以确定血清醛,肝酶,HTG。血清醛包括巴豆醛(CRAL),丙醛(3AL),丁醛(4AL),戊醛(5AL),异芬太尼醛(I5AL),和庚醛(7AL)。肝酶包括丙氨酸转氨酶(ALT),天冬氨酸转氨酶(AST),碱性磷酸酶(ALP),和γ-谷氨酰转移酶(GGT)。HTG定义为空腹TG水平≥1.7mmol/L。使用加权分位数和(WQS)回归和贝叶斯核机回归(BKMR)量化醛共暴露,同时进行了介导分析以研究肝酶的作用。在1474名参与者中(平均年龄38.6岁,男性50.0%),426例被诊断为HTG。4AL,5AL,I5AL,7AL与HTG呈正相关(所有P值<0.05)。醛类共暴露也与HTG呈正相关(OR1.706,95CI1.299-2.240),5AL的权重最高(35.3%)。此外,醛共暴露与ALT呈正相关,AST,和GGT(所有P值<0.05),4种肝酶均与HTG呈正相关(P值均<0.05)。中介分析显示,肝酶(ALT,AST,和GGT)可能介导5AL和7AL与HTG的关联(所有P值<0.05)。这项研究确定了醛共暴露与HTG之间的正相关,可能部分由肝脏酶介导。
    Aldehydes are recognized environmental toxicants that may affect lipid metabolism. For instance, acrolein has been found to increase serum triglyceride (TG) levels exclusively. However, it remains unclear whether other aldehydes are also associated with hypertriglyceridemia (HTG), and what mechanisms may be involved. This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey (NHANES, 2013-2014) to identify associations between serum aldehydes, liver enzymes, and HTG. Serum aldehydes included crotonaldehyde (CRAL), propanaldehyde (3AL), butyraldehyde (4AL), pentanaldehyde (5AL), isopentanaldehyde (I5AL), and heptanaldehyde (7AL). Liver enzymes included alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT). HTG was defined as fasting TG levels ≥ 1.7 mmol/L. Aldehyde co-exposure was quantified using weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR), while mediation analysis was performed to investigate the role of liver enzymes. Among 1474 participants (mean age 38.6 years, male 50.0%), 426 were diagnosed with HTG. 4AL, 5AL, I5AL, and 7AL were shown to be positively associated with HTG (all P values <0.05). Aldehydes co-exposure was also positively associated with HTG (OR 1.706, 95%CI 1.299-2.240), with 5AL contributing the highest weight (35.3%). Furthermore, aldehydes co-exposure showed positive associations with ALT, AST, and GGT (all P values <0.05), and all four liver enzymes were positively associated with HTG (all P values <0.05). Mediation analysis revealed that liver enzymes (ALT, AST, and GGT) may mediate the associations of 5AL and 7AL with HTG (all P values <0.05). This study identified a positive association between aldehyde co-exposure and HTG, which may be partially mediated by liver enzymes.
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  • 文章类型: Journal Article
    在这项研究中,我们研究了三种大豆异黄酮和两种大豆植物甾醇对加热大豆油模型中3-氯丙烷-1,2-二醇脂肪酸酯(3-MCPDE)和醛形成的抑制作用。0.4mM的染料木素,Genistein,Daidzein,豆甾醇,β-谷甾醇使3-MCPDE的形成显著减少了25.7、51.4、21.4、61.6和55.7%,醛形成总量为42.03、43.94、28.36、54.74和39.23%,分别。进一步研究表明,豆甾醇降低了缩水甘油酯(GEs)和缩水甘油的含量,3-MCPDE的两个关键中间体,并防止油中脂肪酸降解。此外,在油条模型系统中评价了连续油炸时间对豆甾醇含量和豆甾醇迁移的影响。发现大豆油中豆甾醇的含量随着加热时间的延长而显着降低。油条中豆甾醇的浓度和豆甾醇从大豆油到油条的迁移率随反复油炸而降低。此外,豆甾醇在热处理过程中经历氧化变化,和氧化产物包括5,6α-环氧豆甾醇,5,6β-环氧豆甾醇,7α-羟基豆甾醇,7β-羟基豆甾醇,stigmasterlol-3β,5α,6β-三醇,在煎炸油中但在油条中没有发现7-酮对甾醇。总的来说,豆油中可以添加豆甾醇以减少3-MCPDE和醛类物质的形成,与GEs/缩水甘油反应和保护脂质免受氧化可能是豆甾醇的作用机理。
    In this study, we investigated the inhibitory effects of three soybean isoflavones and two soybean phytosterols on the formation of 3-chloropropane-1,2-diol fatty acid esters (3-MCPDE) and aldehydes in heated soybean oil model. 0.4 mM of genistin, genistein, daidzein, stigmasterol, and β-sitosterol significantly reduced 3-MCPDE formation by 25.7, 51.4, 21.4, 61.6, and 55.7%, and total aldehydes formation by 42.03, 43.94, 28.36, 54.74, and 39.23%, respectively. Further study showed that stigmasterol reduced the content of glycidyl esters (GEs) and glycidol, two key intermediates of 3-MCPDE, and prevented fatty acids degradation in the oils. Moreover, the effects of continuous frying time on the content of stigmasterol and the migration of stigmasterol were evaluated in the fried dough sticks model system. The content of stigmasterol in soybean oil was found to be significantly decreased with prolonged heating time. The concentrations of stigmasterol in fried dough sticks and the migration rates of stigmasterol from soybean oil to fried dough sticks decreased with repeated frying sessions. In addition, stigmasterol undergoes oxidative changes during heat treatment, and the oxidation products including 5,6α-epoxystigmasterol, 5,6β-epoxystigmasterol, 7α-hydroxystigmasterol, 7β-hydroxystigmasterol, stigmasterlol-3β,5α,6β-triol, and 7-ketostigmasterol were identified in the frying oils but not in the fried dough sticks. Overall, stigmasterol could be added to soybean oil to reduce 3-MCPDE and aldehydes formation, and reacting with GEs/glycidol and protection of lipid acids from oxidation may be the mechanism of action of stigmasterol.
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  • 文章类型: Journal Article
    氨基硫脲及其衍生物已被认为是针对人类病原细菌和真菌的抗微生物剂。关于这些前景,本研究的目的是研究来自缩氨基硫脲及其衍生物的新型抗菌药物。这些衍生物是通过多步合成方法合成的,如烷基化,酸化,酯化,并形成4-(4'-烷氧基苯甲酰氧基)氨基硫脲及其衍生物(THS1,THS2,THS3,THS4和THS5)。之后的合成,化合物通过1HNMR表征,FTIR光谱,和熔点。稍后,将计算工具应用于评估药物相似性特性,生物利用度评分,利平斯基统治,吸收,分布,新陈代谢,排泄,和毒性(ADMET)。其次,量子计算,比如HOMO,LUMO和化学描述符,通过密度泛函理论(DFT)计算。最后,对七种人类致病菌进行了分子对接,黑木耳(Rhizomucormieh,Mucorlusitanicus,耻垢分枝杆菌)和白真菌菌株(念珠菌,鲁川曲霉,白色念珠菌)。为了检查和验证配体和蛋白质对接复合物的分子对接程序和稳定性,对接复合体的分子动力学。从对接分数和计算结合亲和力,这些衍生物可能比标准药物对所有病原体表现出更高的亲和力。从计算细节来看,可以决定进行体外试验作为对金黄色葡萄球菌的抗菌活性,人葡萄球菌,伤寒沙门氏菌,和弯曲志贺氏菌.与标准药物相比,获得的抗菌活性结果,发现合成的化合物与标准药物的价值几乎相同。最后,从体外和计算机研究可以说,氨基硫脲衍生物是良好的抗菌剂。
    The thiosemicarbazones and their derivatives have been recognized as antimicrobial agents against human pathogenic bacteria and fungi. Regarding these prospective, this study was designed to address the new antimicrobial agents from thiosemicarbazones and their derivatives. These derivatives were synthesized by multi-step synthesis methods, such as alkylation, acidification, esterification, and formed the 4-(4\'-alkoxybenzoyloxy) thiosemicarbazones and its derivatives (THS1, THS2, THS3, THS4, and THS5). Afterward the synthesis, compounds were characterized by 1H NMR, FTIR spectra, and melting point. Later, the computational tools were applied to evaluate the drug likeness properties, bioavailability score, Lipinski rule, absorption, distribution, metabolism, excretion, and toxicity (ADMET). Secondly, the quantum calculations, for instance HOMO, LUMO and chemical descriptors, were calculated by the density functional theory (DFT). Finally, the molecular docking was performed against seven human pathogenic bacteria, black fungus (Rhizomucor mieh, Mucor lusitanicus, Mycolicibacterium smegmatis) and white fungus strains (Candida Auris, Aspergillus luchuensis, Candida albicans). To check and validate of molecular docking procedure and stability of docked complex for ligand and protein, the molecular dynamic was performed of docked complex. From the docking score with calculating the binding affinity, these derivatives could show a higher affinity than standard drug against all pathogens. From the computational details, it could be decided to do in-vitro test as antimicrobial activity against Staphylococcus aurious, Staphylococcus homonis, Salmonella typhi, and Shigella flexneria. The obtained result of antibacterial activity compared to standard drugs, and it was found that the synthesized compounds were almost same value of standard drug. Finally, it could be said from the in-vitro and in-silico study that the thiosemicarbazones derivatives are good antimicrobial agents.
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