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排序方式: 共有250条查询结果,搜索用时 31 毫秒
31.
32.
《Scandinavian journal of gastroenterology》2013,48(5):419-423
Six simple phenols in acid-hydrolyzed rat urine have been analyzed by gas chromatography. Following oral neomycin administration a reduction of 96 per cent was observed in the excretion of phenol, p-cresol, and 4-ethylphenol. Guaiacol, which is normally present in trace amounts, was not detected after neomycin treatment. The dihydric phenols, catechol, and 4-methylcatechol decreased by 88 per cent and 50 per cent respectively. After closure of the anal canal the excretion of phenol, 4-ethylphenol, catechol, and 4-methylcatechol decreased while the quantities of p-cresol in the urines increased. 相似文献
33.
《Pharmaceutical biology》2013,51(5):525-532
AbstractContext: There is a need for the discovery of novel natural antioxidants and acetylcholinesterase inhibitors (AChEIs) that are safe and effective at a global level. This is the first study on antioxidant and anti-acethylcholinesterase activity of Scabiosa arenaria Forssk (Dipsacaceae).Objective: The antioxidant potential and anti-acetylcholinesterase (AChE) activity of S. arenaria were investigated.Material and methods: The crude, ethyl acetate (EtOAc), butanol (n-BuOH) and water extracts prepared from flowers, fruits and stems and leaves of S. arenaria were tested to determine their total polyphenol content (TPC), total flavonoid content (TFC), total condensed tannin content (CTC) and their antioxidant activity by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power and β-carotene bleaching inhibition activity. Anti-AChE activity was also determined.Results: EtOAc and n-BuOH fractions of fruits had both the highest (TPC) (269.09?mg gallic acid equivalents/g dry weight). The crude extract of stems and leaves had the highest TFC (10.9?mg quercetin equivalent/g dry weight). The n-BuOH fraction of stems and leaves had the highest CTC (489.75?mg catechin equivalents/g dry weight). The EtOAc fraction of flowers exhibit a higher activity in each antioxidant system with a special attention for DPPH assay (IC50?=?0.017?mg/mL) and reducing power (EC50?=?0.02?mg/mL). The EtOAc and n-BuOH fractions of stems and leaves showed strong inhibition of AChE (IC50?=?0.016 and 0.029?mg/mL, respectively).Discussion and conclusions: These results suggest the potential of S. arenaria as a possible source of novel compounds and as an alternative antioxidant and AChEIs. 相似文献
34.
《Clinical toxicology (Philadelphia, Pa.)》2013,51(2):307-308
AbstractA five year retrospective review of all exposures to a high concentration phenol disinfectant (Creolin Disinfectant 26% phenol) reported to a regional poison center located 96 cases, with 16 cases lost to follow up. There were 60 oral-only exposures, 7 dermal-only exposures and 12 oral/dermal exposure. One patient was an inhalation exposure. Fifty-two cases (65%) were evaluated in a hospital. Eleven patients with oral exposures (14%) experienced rapid CNS depression, but no seizures occurred. Vomiting, coughing, and stridor was noted in 14, 7 and 4 patients respectively. Burns were noted in 17 of 72 (24%) patients with oral exposure and 5 of 19 (26%) with dermal exposure. Seventeen patients underwent endoscopy. Tissue sloughing was noted in one case. All other burns were first degree. No cardiovascular complications occurred. Twenty-eight patients (35%) were followed at home via telephone with one episode of vomiting and one episode of dermal irritation occurring. CNS toxicity from exposure to a high concentration phenol containing cleaning product appears to be rapid in onset. The absence of serious toxicity and major chemical burns in this series does not eliminate concern with the corrosive and systemic risks of phenol poisoning. 相似文献
35.
百样解,又称竹叶兰,是傣族人民最常用的药物之一。百样解中主要含有茋类、酚类、黄酮类等115个化合物,且具有抗肿瘤、抗病毒、抗氧化等多种药理活性。本文综述了百样解的化学成分及药理作用的研究进展,为今后更好地开发利用百样解提供参考。 相似文献
36.
Chemical constituents from heartwoods of Caesalpinia sappan with antiplatelet aggregation activities
Yu Ji Ya-qiong Zhang Tong-dan Liu Meng-yuan Xi Chun-lin Long Li Wang Yue-hu Wang Yi Kong 《中草药(英文版)》2019,11(4):423-428
Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese) and removing blood stasis(Quyu in Chinese).Methods:The chemical constituents were isolated and purified by combination of silica gel and Sephadex LH-20 column chromatography,along with semipreparative HPLC.Their chemical structures were established by multiple spectroscopic methods and comparison with literature data.The in vitro antiplatelet aggregation activities were evaluated using mouse platelet induced by AYPGKF-NH2,a gold agonist of protease-activated receptor 4(PAR4).Results:Two new phenols,methyl 2-(4,4',5'-trihydroxy-2'-(methoxymethyl) biphenyl-2-yloxy) acetate(1)and 1'-methylcaesalpin J(2),together with 24 known compounds(3-26),were isolated from the heartwoods of C.sappan.Among them,sappanchalcone(16) and brazilin(20) showed inhibitory activities against mouse platelet aggregation with IC50 values of 114.8 μmol/L and 100.8 μmol/L,respectively.Conclusion:Antiplatelet compounds from C.sappan targeting at PAR4 are reported for the first time. 相似文献
37.
Ana F. Raimundo Sofia Ferreira Francisco A. Toms-Barbern Claudia N. Santos Regina Menezes 《Nutrients》2021,13(12)
Diabetes remains one of the leading causes of deaths and co-morbidities in the world, with tremendous human, social and economic costs. Therefore, despite therapeutics and technological advancements, improved strategies to tackle diabetes management are still needed. One of the suggested strategies is the consumption of (poly)phenols. Positive outcomes of dietary (poly)phenols have been pointed out towards different features in diabetes. This is the case of ellagitannins, which are present in numerous foodstuffs such as pomegranate, berries, and nuts. Ellagitannins have been reported to have a multitude of effects on metabolic diseases. However, these compounds have high molecular weight and do not reach circulation at effective concentrations, being metabolized in smaller compounds. After being metabolized into ellagic acid in the small intestine, the colonic microbiota hydrolyzes and metabolizes ellagic acid into dibenzopyran-6-one derivatives, known as urolithins. These low molecular weight compounds reach circulation in considerable concentrations ranging until micromolar levels, capable of reaching target tissues. Different urolithins are formed throughout the metabolization process, but urolithin A, isourolithin A, and urolithin B, and their phase-II metabolites are the most frequent ones. In recent years, urolithins have been the focus of attention in regard to their effects on a multiplicity of chronic diseases, including cancer and diabetes. In this review, we will discuss the latest advances about the protective effects of urolithins on diabetes. 相似文献
38.
Lorena Snchez-Martínez María-Jesús Periago Javier García-Alonso María-Teresa García-Conesa Rocío Gonzlez-Barrio 《Nutrients》2021,13(12)
Menopause is characterized by endocrine and physiological changes and is often accompanied by increased body weight and cholesterol, glucose intolerance, and/or hypertension. These alterations are associated with increased risk for cardiovascular diseases (CVDs) and Type II diabetes mellitus (T2DM) that may be moderate by dietary plant phenolic compounds. In this review, we examine the current evidence of the impact of a variety of plant products (foods, extracts, beverages) rich in a mixture of phenolics and polyphenols on: (i) glucose and insulin levels; (ii) lipid profile; (iii) blood pressure; and (iv) biomarkers of inflammation and oxidative stress in postmenopausal women. We critically evaluate both the results of a range of intervention studies conducted in this specific subpopulation and the level of evidence supporting the benefits of consuming those products after the menopause. Overall, the current available evidence does not allow for specific dietary recommendations of these plant products rich in phenolics and polyphenols in this high-risk subpopulation. Our data show rather variable and small effects of the different products examined on the cardiometabolic biomarkers and further support the need to: (1) improve the quality of the study designs and data reporting; and (2) understand the variability in the response of the different biomarkers and establish clear differences between healthy and cardiometabolic disease levels. 相似文献
39.
In plants, accumulation in specific compartments and huge structural diversity of secondary metabolites is one trait that is not understood yet. By exploring the diverse abiotic and biotic interactions of plants above- and belowground, we provide examples that are characterized by nonlinear effects of the secondary metabolites. We propose that redox chemistry, specifically the reduction of reactive oxygen species (ROS) and, in their absence, reduction of molecular oxygen by the identical secondary metabolite, is an important component of the hormetic effects caused by these compounds. This is illustrated for selected phenols, terpenoids, and alkaloids. The redox reactions are modulated by the variable availability of transition metals that serve as donors of electrons in a Fenton reaction mode. Low levels of ROS stimulate growth, cell differentiation, and stress resistance; high levels induce programmed cell death. We propose that provision of molecules that can participate in this redox chemistry is the raison d'être for secondary metabolites. In this context, the presence or absence of functional groups in the molecule is more essential than the whole structure. Accordingly, there exist no constraints that limit structural diversity. Redox chemistry is ubiquitous, from the atmosphere to the soil. 相似文献
40.
响应面法优化松花粉总酚的超声提取工艺 总被引:1,自引:1,他引:0
目的:优选松花粉中总酚的超声提取工艺.方法:以总酚得率为指标,采用单因素试验考察乙醇体积分数、超声时间、超声温度、料液比等因素对总酚得率的影响,在此基础上,运用响应面法优选总酚超声提取工艺.结果:松花粉总酚的最佳超声提取工艺条件为30倍量39%乙醇于51℃下超声提取24 min,在此条件下,总酚得率3.85 mg·g-1,实测值与模型预测值相符.结论:响应面分析法可较好地用于优化松花粉总酚超声提取工艺,且该优选工艺方便、快捷、高效. 相似文献