Characterization and density functional theory study of the antioxidant activity of quercetin and its sugar-containing analogues

Inhibition of free radicals using quercetin, hyperin and rutin is examined to determine their antioxidant effects and the structure-activity relationships of flavonoids. Two species of the free radicals are used, including hydroxyl radical (.OH) and superoxide anion radical (O-2(-)). Density functional theory calculations under the level of B3LYP/6-311G (d) have been utilized to explore the structure, molecular properties and antioxidant abilities of the three flavonoids. Bond dissociation enthalpy (BDE) and frontier molecular orbital energy gap are investigated. They are compared with the experiment results assayed by the spectrophotometric. All of the flavonoids show a high activity on inhibiting OH and O-2(-) radicals. Scavenging activity determined by half maximal inhibitory concentration (IC50) values of the three flavonoids decreases in the order: quercetin > hyperin > rutin. The calculations show that quercetin owns the lowest BDE values, which agree well with the experimental results of antioxidant activity determined by IC50 values

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

dftstudyofbenzofuroxansynthesismechanismfrom2nitroanilineviasodiumhypochlorite

用密度泛函理论在B3LYP／6—31G（d，p）计算水平下研究了次氯酸钠氧化邻硝基苯胺生成苯并氧化呋咱的环氧化反应．考虑溶剂化效应对反应的影响，使用极化连续反应场模型进行几何优化．计算了该反应的两种可能反应通道，它们都是分步反应，反应通道A经历氧化、移氧、脱水和环化四步反应，在反应通道B中，氢氧化钠的OH^-首先进攻邻硝基苯胺的胺基H原子，生成邻硝基苯亚胺负离子．计算结果表明，在反应通道A是可行的反应通道，1个水分子辅助进行分子内脱水反应是速控步骤

dftstudyofbenzofuroxansynthesismechanismfrom2nitroanilineviasodiumhypochlorite

用密度泛函理论在B3LYP／6—31G（d，p）计算水平下研究了次氯酸钠氧化邻硝基苯胺生成苯并氧化呋咱的环氧化反应．考虑溶剂化效应对反应的影响，使用极化连续反应场模型进行几何优化．计算了该反应的两种可能反应通道，它们都是分步反应，反应通道A经历氧化、移氧、脱水和环化四步反应，在反应通道B中，氢氧化钠的OH^-首先进攻邻硝基苯胺的胺基H原子，生成邻硝基苯亚胺负离子．计算结果表明，在反应通道A是可行的反应通道，1个水分子辅助进行分子内脱水反应是速控步骤

Xanthohumol protect against acetaminophen-induced hepatotoxicity via Nrf2 activation through the AMPK/Akt/GSK3β pathway

Objective: Acetaminophen (APAP) is one of the world's popular and safe painkillers, and overdose can cause severe liver damage and even acute liver failure. The effect and mechanism of the xanthohumol on acetaminophen-induced hepatotoxicity remains unclear. Methods: The hepatoprotective effects of xanthohumol were studied using APAP-induced HepG2 cells and acute liver injury of mouse, seperately. Results: In vitro, xanthohumol inhibited H2O2- and acetaminophen-induced cytotoxicity and oxidative stress. Xanthohumol up-regulated the expression of Nrf2. Further mechanistic studies showed that xanthohumol triggered Nrf2 activation via the AMPK/Akt/GSK3β pathway to exert a cytoprotective effect. In vivo, xanthohumol significantly ameliorated acetaminophen-induced mortality, the elevation of ALT and AST, GSH depletion, MDA formation and histopathological changes. Xanthohumol effectively suppressed the phosphorylation and mitochondrial translocation of JNK, mitochondrial translocation of Bax, the activation o cytochrome c, AIF secretion and Caspase-3. In vivo, xanthohumol increased Nrf2 nuclear transcription and AMPK, Akt and GSK3β phosphorylation in vivo. In addition, whether xanthohumol protected against acetaminophen-induced liver injury in Nrf2 knockout mice has not been illustated. Conclusion: Thus, xanthohumol exerted a hepatoprotective effect by inhibiting oxidative stress and mitochondrial dysfunction through the AMPK/Akt/GSK3β/Nrf2 antioxidant pathway

Natural Fractures in Carbonate Basement Reservoirs of the Jizhong Sub-Basin, Bohai Bay Basin, China: Key Aspects Favoring Oil Production

Analysis of natural fractures is essential for understanding the heterogeneity of basement reservoirs with carbonate rocks since natural fractures significantly control key attributes such as porosity and permeability. Based on the observations and analyses of outcrops, cores, borehole image logs, and thin sections from the Mesoproterozoic to Lower Paleozoic in the Jizhong Sub-Basin, natural fractures are found to be abundant in genetic types (tectonic, pressure-solution, and dissolution) in these reservoirs. Tectonic fractures are dominant in such reservoirs, and lithology, mechanical stratigraphy, and faults are major influencing factors for the development of fractures. Dolostones with higher dolomite content are more likely to have tectonic fractures than limestones with higher calcite content. Most tectonic fractures are developed inside mechanical units and terminate at the unit interface at nearly perpendicular or high angles. Also, where a thinner mechanical unit is observed, tectonic fractures are more frequent with a small height. Furthermore, the dominant direction of tectonic fractures is sub-parallel to the fault direction or oblique at a small angle. In addition, integrating diverse characteristics of opening-mode fractures and well-testing data with oil production shows that, in perforated intervals where dolostone and limestone are interstratified or dolostone is the main lithologic composition, fractures are developed well, and the oil production is higher. Moreover, fractures with a larger dip angle have bigger apertures and contribute more to oil production. Collectively, this investigation provides a future reference for understanding the importance of natural fractures and their impact on oil production in the carbonate basement reservoirs