Effects of Green Apple (Golden Delicious) and Its Three Major Flavonols Consumption on Obesity,Lipids, and Oxidative Stress in Obese Rats

Obesity is becoming increasingly common all over the world and global strategies are accordingly being developed to prevent it. In order to support the strategies, the effects of green apple (Golden Delicious) and the consumption of its three major flavonols (quercetin-3-glucoside, quercetin-3-D-galactoside, and quercetin-3-rhamnoside) on body weight; the weight of liver, kidney, and spleen; some lipid parameters in serum; and total lipid ratios of liver and kidney and oxidative stress parameters of obese rats were studied. This study was conducted on two experimental groups: one of which was given an apple, and the other was given flavonols, in addition to their high-energy diet; along with a sham and a control rat group, for 4 weeks. According to results, there was no difference in body and organ weights between groups. The liver and kidney weights increased in obese rats, but there was no difference between the total lipid ratios in these organs. The addition of green apple and selected flavonols to the high-energy diet of rats was not sufficient to prevent the increase in body and organ weights, but it supported the reduction in some lipid fractions and in oxidative stress parameters of obese rats. Moreover, this study supported the argument that obesity causes most of the lipid fractions increase in serum and induces oxidative stress.     

三维有序金掺杂纳米TiO_2修饰电极用于抗肿瘤药物与DNA相互作用的研究

利用模板法在氧化铟锡(ITO)电极表面制备了三维有序多孔结构的金掺杂纳米Ti O2薄膜修饰电极(3DOM GTD/ITO),并在此修饰电极上成功固定小牛胸腺DNA(ct DNA),从而构建了一种新型的DNA生物传感器(DNA/3DOM GTD/ITO),并通过透射电镜(TEM)、扫描电镜(SEM)对修饰电极的表面形貌进行表征。采用电化学交流阻抗(EIS)法研究了ct DNA在3DOM GTD/ITO修饰电极表面的固定情况,结果表明,ct DNA已被成功地固定在3DOM GTD/ITO修饰电极表面。采用循环伏安法、微分脉冲伏安法等电化学方法研究了抗肿瘤药物槲皮素(Qu)在3DOM GTD/ITO修饰电极表面的电化学性质及与ct DNA的相互作用。结果表明,Qu在3DOM GTD/ITO修饰电极表面有1对准可逆的氧化还原峰,其氧化还原反应为2电子和2质子的转移过程。Qu可与固定在修饰电极上的ct DNA发生较强的结合作用,其结合常数(K)为3.61×106L/mol。循环伏安实验、紫外-可见吸收光谱、分子荧光光谱、圆二色性光谱均表明Qu与ct DNA之间的相互作用模式为嵌插作用。Qu与ct DNA的碱基结合具有序列选择性,对Qu与聚(d G-d C)及聚(d A-d T)的结合常数进行计算,得到结合常数比K(d G-d C)/K(d A-d T)=3.5,表明Qu与ct DNA发生嵌插作用时更倾向于结合在GC富集区域。     

毛细管电泳法测定桑叶中的黄酮类成分──芦丁和槲皮素

 采用高效毛细管电泳法分离测定了新疆不同地区、不同采集期、不同品种的桑叶中的黄酮类成分芦丁、槲皮素的含量。以含有体积分数为 15 %甲醇的 10mmol/L的磷酸二氢钠 2 0mmol/L的硼砂溶液 (pH 8 6 2 )为电泳缓冲液 ,采用压力进样方式 ,在 2 5℃ ,2 0kV恒压下进行电泳分离 ,并在 2 45nm波长处检测。结果表明 ,桑叶中的两种目标组分在 12min内完全分离 ,且有良好的线性关系 ;芦丁和槲皮素的加样回收率分别为 95 6 4%和99 36 % ,其RSD分别为 2 2 5 %和 1 79% (n =6 )。方法简单、准确、快速。     

槲皮素及其异构体分子的结构性质研究

槲皮素是一类有着重要药理活性的黄酮类化合物。本文在B3LYP/6-31G**水平上对槲皮素及其14种异构体进行了几何优化,得到各种异构体的结构与性质。由电荷布居数分析出B环是此类多羟基化合物的活性部分,3位-OH的存在抑制了A、C环的活性。同时,表明此类化合物中必有分子内氢键形成。并给出了最稳构型、槲皮素和标准结构三类分子的振动光谱。探讨了它们的构效关系。     

Oligomeric oxidation products of the flavonoid quercetin

Some of the main oxidation products of quercetin were shown to be compounds formed by oligomerization of the starting flavonoid. Conditions for the preparative synthesis of these compounds were developed. Their structures were established using HPLC-MS and NMR methods. Quercetin oligomers in the natural sample, outer leaves of modified runners of Allium cepa L., were found using chromatographic procedures. The use of quercetin oligomers as indicators of its oxidation was proposed. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 344–347, July–August, 2008.     

Antioxidant Cardioprotection against Reperfusion Injury: Potential Therapeutic Roles of Resveratrol and Quercetin

Ischemia-reperfusion myocardial damage is a paradoxical tissue injury occurring during percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) patients. Although this damage could account for up to 50% of the final infarct size, there has been no available pharmacological treatment until now. Oxidative stress contributes to the underlying production mechanism, exerting the most marked injury during the early onset of reperfusion. So far, antioxidants have been shown to protect the AMI patients undergoing PCI to mitigate these detrimental effects; however, no clinical trials to date have shown any significant infarct size reduction. Therefore, it is worthwhile to consider multitarget antioxidant therapies targeting multifactorial AMI. Indeed, this clinical setting involves injurious effects derived from oxygen deprivation, intracellular pH changes and increased concentration of cytosolic Ca²⁺ and reactive oxygen species, among others. Thus, we will review a brief overview of the pathological cascades involved in ischemia-reperfusion injury and the potential therapeutic effects based on preclinical studies involving a combination of antioxidants, with particular reference to resveratrol and quercetin, which could contribute to cardioprotection against ischemia-reperfusion injury in myocardial tissue. We will also highlight the upcoming perspectives of these antioxidants for designing future studies.     

Reaction of Bioflavonoids with Copper(II) Acetate in Aqueous Solution

The reaction of dihydroquercetin, quercetin, and rutin with Cu(II) acetate in aqueous solution is studied. Quercetin and dihydroquercetin form complexes with Cu. The water-insoluble complexes are characterized as chelates of the 3,4-positions of the main -pyrone ring. Electronic spectroscopy showed the presence of stable polynuclear rutin complexes of composition rutin :Cu = 1:x, where x > 2.     

Chemical Composition of Certain Sedum Species of Kazakhstan

The chemical composition of sevenSedumspecies growing in Kazakhstan was studied by chromatography. The contents of seven groups of natural compounds were determined. Comparison with markers and literature data identified 24 compounds including 9 that have not been described previously inSedumspecies     

槲皮素-Sn(Ⅱ)配合物荧光、紫外及红外光谱的测量与分析

以NH4Cl-NH3·H2O为缓冲液,十六烷基三甲基溴化铵(CTAB)为荧光增强剂,用荧光分光光度计分别采集槲皮素、槲皮素-Sn(Ⅱ)配合物溶液、槲皮素-Sn(Ⅱ)-NH4Cl-NH3·H2O、槲皮素-Sn(Ⅱ)-NH4Cl-NH3·H2O-CTAB溶液以及将其溶液分别静置7h和21h后的荧光光谱,并对光谱进行分析.在不加CTAB的条件下,用紫外分光光度计分别测量加入缓冲液前后的紫外光谱.用漫反射方法测定配合物的红外光谱,并对其结构进行初步分析.在缓冲液的作用下,槲皮素-Sn(Ⅱ)配合物的结构发生了变化;通过分析,发现与缓冲液发生反应的主要基团为酚羟基,红外光谱中酚羟基的消失和NH 4基团的出现,说明了配合物中的酚羟基与NH 4发生了取代反应.