Catechols

儿茶酚
  • 文章类型: Journal Article
    药理学的动态发展需要AI技术来推进药物开发的新道路。作者提出了未来药物的生成AI,确定合适的药物分子,与前几代药物不同,融入智慧,经验,以及传统医学和各自的传统医学从业者的直觉。本文阐述了新药开发的指导原则,从藏医的传统和实践中,定义为交互式营养过程(INP)。INP提供传统知识和从业者的经验,新药物疗法的情境化和教学。INP结果的一个说明性例子是一种潜在的小分子药物,6-Shogaol和相关的Shogaol衍生物,从姜根(生姜。姜科)对骨髓增生异常综合征(MDS)患者的铁稳态生物学标志物进行了12个月的临床评估。该研究的初步结果表明,6-Shogaol和相关Shogaol可以改善低危/中度-1MDS患者的铁稳态,而没有客观或主观副作用。
    The dynamically evolving science of pharmacology requires AI technology to advance a new path for drug development. The author proposes generative AI for future drugs, identifying suitable drug molecules, uncharacteristically to previous generations of medicines, incorporating the wisdom, experience, and intuit of traditional materia medica and the respective traditional medicine practitioners. This paper describes the guiding principles of the new drug development, springing from the tradition and practice of Tibetan medicine, defined as the Interactive Nutrient Process (INP). The INP provides traditional knowledge and practitioner\'s experience, contextualizing and teaching the new drug therapy. An illustrative example of the outcome of the INP is a potential small molecule drug, 6-Shogaol and related shogaol derivatives, from ginger roots (Zingiber officinalis fam. Zingiberaceae) evaluated clinically for 12 months for biological markers of iron homeostasis in patients with the myelodysplastic syndromes (MDS). The study\'s preliminary results indicate that 6-Shogaol and related shogaols may improve iron homeostasis in low-risk/intermediate-1 MDS patients without objective or subjective side effects.
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  • 文章类型: Journal Article
    植物激素水杨酸(SA)在植物先天免疫中起着至关重要的作用。确定了几种SA衍生物和相关的修饰,而SA相关代谢物的范围和作用方式仍然难以捉摸。这里,该研究发现2,4-二羟基苯甲酸(2,4-DHBA)及其糖基化形式在植物中作为天然SA衍生物,其积累主要由SA施用和Ps诱导。山茶花(Pcs)感染。CsSH1,一种4/5-羟化酶,催化SA羟化为2,4-DHBA,UDP-葡萄糖基转移酶UGT95B17催化2,4-DHBA葡糖苷的形成。下调降低了2,4-DHBA葡糖苷的积累,并增强了茶树对Pcs的敏感性。相反,UGT95B17的过表达增加了植物的抗病性。2,4-DHBA和2,5-DHBA的外源施用,以及DHBA的积累和植物抗性的比较,表明2,4-DHBA作为潜在的生物活性分子起作用,并且主要作为葡萄糖缀合物在茶树中储存,与拟南芥中描述的机制不同。当2,4-DHBA外源施用时,UGT95B17沉默的茶树比SA积累更多的2,4-DHBA,并显示出对Pcs感染的诱导抗性。这些结果表明,2,4-DHBA糖基化正调节抗病性,并突出了2,4-DHBA作为潜在生物活性分子在茶树基础抗性建立中的作用。
    The plant hormone salicylic acid (SA) plays critical roles in plant innate immunity. Several SA derivatives and associated modification are identified, whereas the range and modes of action of SA-related metabolites remain elusive. Here, the study discovered 2,4-dihydroxybenzoic acid (2,4-DHBA) and its glycosylated form as native SA derivatives in plants whose accumulation is largely induced by SA application and Ps. camelliae-sinensis (Pcs) infection. CsSH1, a 4/5-hydroxylase, catalyzes the hydroxylation of SA to 2,4-DHBA, and UDP-glucosyltransferase UGT95B17 catalyzes the formation of 2,4-DHBA glucoside. Down-regulation reduced the accumulation of 2,4-DHBA glucosides and enhanced the sensitivity of tea plants to Pcs. Conversely, overexpression of UGT95B17 increased plant disease resistance. The exogenous application of 2,4-DHBA and 2,5-DHBA, as well as the accumulation of DHBA and plant resistance comparison, indicate that 2,4-DHBA functions as a potentially bioactive molecule and is stored mainly as a glucose conjugate in tea plants, differs from the mechanism described in Arabidopsis. When 2,4-DHBA is applied exogenously, UGT95B17-silenced tea plants accumulated more 2,4-DHBA than SA and showed induced resistance to Pcs infection. These results indicate that 2,4-DHBA glucosylation positively regulates disease resistance and highlight the role of 2,4-DHBA as potentially bioactive molecule in the establishment of basal resistance in tea plants.
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  • 文章类型: Letter
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  • 文章类型: Journal Article
    The ultimate goal in the understanding of complex chemical processes is a complete description of the underlying reaction mechanism. In the present study and for this purpose, a novel experimental platform is introduced that builds upon electrochemistry capable of generating reactive intermediate species at the electrode surface. The atmospherically relevant nitration of catechols is taken as a case example. First, we confirm the recently proposed nitration mechanism, advancing the understanding of atmospheric brown carbon formation in the dark. We are able to selectively quantify aromatic isomers, which is beyond the limits of conventional electroanalysis. Second, we identify a new pathway of nitrocatechol hydroxylation, which proceeds simply by oxidation and the addition of water. This pathway can be environmentally significant in the dark aqueous-phase formation of secondary organic aerosols. Third, the developed methodology is capable of selectively detecting a wide range of nitroaromatics; a possible application in environmental monitoring is proposed.
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  • 文章类型: Journal Article
    方法:儿茶酚部分通常存在于发挥癌症化学预防活性的膳食天然产物中。虽然儿茶酚氧化转化为其相应的邻醌通常被认为有助于其癌症化学预防作用,细胞内转化的机制尚未完全阐明。
    结果:在检查的白藜芦醇及其羟基化类似物中,只有3,4-二羟基-反式-二苯乙烯对叔丁基过氧化氢诱导的HepG2细胞死亡具有细胞保护作用。这种白藜芦醇类似物通过刺激Akt磷酸化和诱导keap1修饰激活核因子红系2相关因子2(Nrf2)途径,从而导致其核易位和随后的II期解毒酶的转录诱导。通过用DTT预处理细胞,其通过Nrf2激活的细胞保护作用在很大程度上被消除。含巯基的亲核试剂,和新奥普林,一种特殊的铜离子螯合剂。
    结论:我们鉴定了3,4-二羟基-反式-二苯乙烯作为新型Nrf2活化剂,其通过铜离子在细胞内转化为其相应的邻醌亲电试剂。Nrf2活化需要铜介导的氧化,随后转录诱导II期解毒酶,并最终用于细胞保护。研究结果表明,细胞内铜离子在含儿茶酚的饮食天然产物的癌症化学预防作用中的作用先前尚未得到认可。
    METHODS: Catechol moieties are commonly present in dietary natural products that exert cancer chemopreventive activity. While the oxidative conversion of catechols into their corresponding o-quinones is generally considered to contribute to their cancer chemopreventive effects, the mechanism of the intracellular conversion has not been fully elucidated.
    RESULTS: Among resveratrol and its hydroxylated analogs examined, only 3,4-dihydroxy-trans-stilbene exerted cytoprotective effects against t-butylhydroperoxide-induced death of HepG2 cells. This resveratrol analog activated the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway through stimulating phosphorylation of Akt and inducing keap1 modification, thereby resulting in its nuclear translocation and subsequent transcriptional induction of phase II detoxifying enzymes. Its cytoprotective effect through Nrf2 activation was largely abrogated by pretreatment of cells with DTT, a sulfhydryl-containing nucleophile, and neocuproine, a specific chelating agent for copper ions.
    CONCLUSIONS: We identified 3,4-dihydroxy-trans-stilbene as a novel Nrf2 activator that is converted intracellularly into its corresponding o-quinone electrophile by copper ions. The copper-mediated oxidation was required for the Nrf2 activation, subsequent transcriptional induction of phase II detoxifying enzymes and ultimately for cytoprotection. The findings demonstrate a previously underrecognized role for intracellular copper ions in the cancer chemopreventive effects of catechol-containing dietary natural products.
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  • 文章类型: Journal Article
    A new method based on nano-liquid chromatography coupled to time-of-flight mass spectrometry (nano-LC-TOF-MS) using lock-mass calibration was developed to facilitate the accurate and routine characterization and quantification of phenolic compounds. Thus, it was applied to study cranberry syrups, in which, using negative ionization mode, a total of nine phenolic compounds were unequivocally identified using standards and 38 tentatively taking into account their retention time, accurate mass (errors<5 ppm) data and isotope pattern, as well as literature. Among them, 13 compounds, belonging to flavonols and iridoids conjugated with phenolic acids, were reported for first time in cranberry or cranberry based-products. The analytical method was also validated using chlorogenic acid, p-coumaric acid, (+)-catechin, (-)-epicatechin, procyanidin A2, quercetin 3-O-glucoside, quercetin 3-O-rhamnoside, quercetin, and myricetin standards. In this way, the analytical method showed adequate linearity, with R(2) above 0.99, and acceptable values of intra- and inter-day repeatability of the retention time and peak area. The detection limits and quantification were between 1.0-15.6 ng mL(-1) and 2.0-62.5 ng mL(-1), respectively. The method can be extended to characterize phenolic compounds in other food and plant matrices, and as well biological samples.
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  • 文章类型: Case Reports
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  • 文章类型: Journal Article
    Due to regulatory constraints and ethical considerations, the quest for alternatives to animal testing has gained a new momentum. In general, animal welfare considerations and compliance with regulations are the key drivers for this research. Mechanistically based in vitro tests addressing specific toxicological questions can yield new information, for example on reactive components, and thus in certain cases the in vitro tests are not only second choice replacements of a \'gold standard\' animal test but can also be used to develop safer products. Here we report a case study from the in vitro investigation on the commercial fragrance chemical Azurone. This compound was found to be a moderate skin sensitizer in the LLNA, whereas the structurally closely similar compound Calone is a non-sensitizer. A peptide reactivity assay indicated, that indeed Azurone yields peptide depletion, thus the in vitro assays confirmed the animal test result. LC-MS analysis of the peptide reactivity sample showed the presence of peptide adducts of unexpected molecular weight. They were consistent with the reaction of the peptide with a catechol related to Azurone. Detailed analytics indicated that indeed this catechol is present in the original batches as an impurity, but it has escaped quality control analysis, as it is not detectable in routine GC-analysis. A new purified batch was prepared, re-tested in the in vitro assays and predicted by the tests to be a non-sensitizer. A confirmatory LLNA test indeed yielded a significantly (10-fold) higher EC3 value of the new batch, but the LLNA was still positive. A dose-response study in the EpiSkin assay indicated that this molecule still has a significant skin irritation potential, which may generate the weak positive signal in the LLNA. This case study illustrates how the mechanistically based in vitro LC-MS peptide reactivity assay can be used to contribute to the understanding of the sensitization mechanism of a commercial product and help to define a safer product specification.
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  • 文章类型: Journal Article
    Many industries employ the activated sludge process for biological removal of pollutants present in wastewater. Yet, treatment plants do notfunction at optimum potential. The biological component of such systems remains a black box, and reasons responsible for poor performance have not been identified. We have used genomic and physiological tools to understand the process and propose that analysis of catabolic signatures and nutrient levels, are crucial parameters in assessing and monitoring the performance of an effluent treatment plant. In this study, we use activated sludge collected from a refinery running at a capacity of 8 million metric tonnes of wastewater as a model. The presence of hydroxylases, oxygenases, and dioxygenases in the biomass was demonstrated by polymerase chain reaction and sequence analysis of aromatic-ring hydroxylating dioxygenase clones extracted from the metagenome, suggests the presence of hitherto unreported enzymes. The actual degradative state of the biomass was demonstrated by respirometric analysis using 11 substrates expected in refinery wastewater. Nutrient-levels required for the microbial population were estimated by on-site analysis. Diagnosis of the degradative potential of activated sludge can be carried out by incorporating these tools in regular monitoring procedures and can setthe rules for improving the efficiency of treatment
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  • 文章类型: Case Reports
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