山楂叶中黄酮含量的高效液相色谱法测定

研究了山楂叶中黄酮的提取和检测方法。以水为提取溶剂并用微波法提取,山楂的提取物质酸解后,以甲醇:水(60:40)为流动相,检测波长365nm,流速为1.0mL/min。山楂叶中槲皮素、牡荆素和异鼠李素的含量分别为3.69mg/g、7.98mg/g、2.02mg/g,回收率分别为99.03%、96.28%、100.19%。该提取和测定方法经济适用、效果好,而且具有简单、准确、快速等优点。     

紫斑牡丹花粉中异鼠李素的定性定量分析及总黄酮的含量测定

目的:建立甘肃紫斑牡丹花粉中异鼠李素的定性定量分析及总黄酮含量测定的方法。方法:采用薄层色谱法对紫斑牡丹花粉中异鼠李素进行定性鉴别;采用高效液相色谱法,以Agilent Eclipse plus C18色谱柱（250 mm×4.6 mm,5μm）为固定相,流动相:甲醇-乙腈-0.1%磷酸（25∶13∶62）,流速:1.0 m L·min-1,在360 nm波长下,对紫斑牡丹花粉中异鼠李素的含量进行定量分析。采用紫外分光光度法,以芦丁为对照品,在510 nm波长下,对紫斑牡丹花粉中总黄酮含量进行测定。结果:薄层鉴别色谱特征斑点明显,重现性好;异鼠李素浓度在8.4¹68.0μg·m L-1范围内与峰面积呈良好的线性关系（r=0.9999）,平均回收率（n=9）为100.8%（RSD=2.36%）,测得紫斑牡丹花粉中异鼠李素含量为3.21⁸.91 mg·g^-1。总黄酮浓度在0.01⁰.06 mg·m L-1范围内与吸收度呈良好的线性关系（r=0.9992）,平均回收率（n=9）为101.06%（RSD=2.56%）,测得紫斑牡丹花粉中总黄酮含量为9.44¹5.96 mg·g^-1。结论:所建方法操作简单,准确可靠,重复性好,可用于甘肃紫斑牡丹花粉的质量控制。      

Anti-Obesity Effects of Isorhamnetin and Isorhamnetin Conjugates

Isorhamnetin is a plant-derived secondary metabolite which belongs to the family of flavonoids. This review summarises the main outcomes described in the literature to date, regarding the effects of isorhamnetin on obesity from in vitro and in vivo studies. The studies carried out in pre-adipocytes show that isorhamnetin is able to reduce adipogenesis at 10 μM or higher doses and that these effects are mediated by Pparγ and by Wnt signalling pathway. Very few studies addressed in rodents are available so far. It seems that treatment periods longer than two weeks are needed by isorhamnetin and its glycosides to be effective as anti-obesity agents. Nevertheless, improvements in glycaemic control can be observed even in short treatments. Regarding the underlying mechanisms of action, although some contradictory results have been found, reductions in de novo lipogenesis and fatty acid uptake could be proposed. Further research is needed to increase the scientific evidence referring to this topic; studies in animal models are essential, as well as randomised clinical trials to determine whether the positive results observed in animals could also be found in humans, in order to determine if isorhamnetin and its glycosides can represent a real tool against obesity.     

2种新疆沙棘中黄酮、多酚及其抗氧化活性分析

以新疆2种沙棘为研究对象,使用分光光度法、超高效液相色谱法对其黄酮(槲皮素、山奈酚、异鼠李素)、多酚含量及抗氧化活性(DPPH自由基、铁离子自由基、还原力、总抗氧化能力、铁离子螯合能力)进行比较分析。结果表明,沙棘A黄酮、多酚含量分别为(7.02±0.19)、(5.48±0.42)mg·g^-1,沙棘B黄酮、多酚含量分别为(9.56±0.53)、(24.33±1.44)mg·g^-1,沙棘B的黄酮、多酚含量均高于沙棘A。沙棘A、B的DPPH清除率IC₅₀浓度值分别为(128.953±0.098)和(7.521±0.027)μg·mL^-1;当沙棘浓度为1 mg·mL^-1时,沙棘A的FRAP值、T-AOC值、还原力测定值和铁离子螯合测定值分别为(0.5611±0.0042)mmol·L^-1、(6.0457±0.3402)U·mL^-1、(0.2071±0.0113)和(0.3003±0.0164),沙棘B的FRAP值、T-AOC值、还原力测定值和铁离子螯合测定值分别为浓度为(0.4853±0.0067)mmol·L^-1、(4.5318±0.1553)U·mL^-1、(0.2399±0.0104)和(0.8851±0.0077);由此可见,二者抗氧化活性差别不大,沙棘B略高于沙棘A;沙棘A的槲皮素、山奈酚、异鼠李素含量分别为(0.6708±0.0410)、(0.0788±0.0292)和(1.5814±0.0372)mg·g^-1,沙棘B的槲皮素、山奈酚、异鼠李素含量分别为(0.9438±0.0403)、(0.1194±0.0153)和(1.0727±0.0406)mg·g^-1;沙棘B的槲皮素、山奈酚含量均高于沙棘A,而沙棘A的异鼠李素含量明显高于沙棘B。综上,沙棘B具有较高的黄酮、多酚含量及略优的抗氧化活性。     

Scale-up purification for rutin hyrdrolysates by high-performance counter-current chromatography coupled with semi-preparative high-performance liquid chromatography

The study made the isolation of three constituents from rutin and exemplified how to achieve quercetin separation and quantification in rapid and scale-up processes by high-performance counter-current chromatography (HPCCC). Meanwhile, we also isolated the other two constituents, kaempferol and isorhamnetin, by semi-preparative high-performance liquid chromatography. After systematic optimization of solvent systems, sample concentration and flow rate on analytical Mini-DE centrifuge, the same conditions were scale-up by 50-fold in preparative Midi-DE centrifuge to purify quercetin, and the maximum sample loading achieved 1.65 g. Eventually, we successfully isolated quercetin, kaempferol and isorhamnetin with the purity of 99.80%, 99.84% and 99.95%, respectively. The process, therefore, provided an efficient method of obtaining sufficient quantities of highly purified quercetin, as well as kaempferol and isorhamnetin.     

高效液相色谱法测定风柜斗草中槲皮素和异鼠李素的含量

目的：建立闽南草药风柜斗草中槲皮素和异鼠李素含量测定的方法。方法：采用70%甲醇超声提取,HPLC-PDA分析方法测定。色谱条件为色谱柱Ultimate Column TMC18 4.6×150mm×5μm,流动相甲醇∶0.5%磷酸=55∶45,流速：1.0 mL/min,柱温：30℃,检测波长：370nm。结果：闽南...     

HPLC法测定银刺胶囊中总黄酮的含量

采用高效液相色谱法测定银刺胶囊中银杏总黄酮的含量,将其作为胶囊的质量控制方法,并将单对照品测定法(以槲皮素为单一对照品)与三对照品测定法(以槲皮素、山奈素、异鼠李素为对照品)进行了比较,证明了三对照品法的优点。     

Isorhamnetin Ameliorates Dry Eye Disease via CFTR Activation in Mice

Dry eye disease is one of the most common diseases, with increasing prevalence in many countries, but treatment options are limited. Cystic fibrosis transmembrane conductance regulator (CFTR) is a major ion channel that facilitates fluid secretion in ocular surface epithelium and is a potential target of therapeutic agent for the treatment of dry eye disease. In this study, we performed a cell-based, high-throughput screening for the identification of novel natural products that activate CFTR and restore the aqueous deficiency in dry eye. Screening of 1000 natural products revealed isorhamnetin, a flavonol aglycone, as a novel CFTR activator. Electrophysiological studies showed that isorhamnetin significantly increased CFTR chloride current, both wild type and ∆F508-CFTR. Isorhamnetin did not alter intracellular cAMP levels and the activity of other ion channels, including ANO1, ENaC, and hERG. Notably, application of isorhamnetin on mouse ocular surface induced CFTR activation and increased tear volume. In addition, isorhamnetin significantly reduced ocular surface damage and expression of interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in an experimental mouse model of dry eye. These data suggest that isorhamnetin may be used to treat dry eye disease.     

HPLC法测定牙膏中银杏叶提取物总黄酮苷的含量

以槲皮素、山奈素和异鼠李素为指标,建立HPLC法测定牙膏中银杏叶提取物总黄酮苷的含量。采用Agilent ZORBAX Eclipse XDB-C18色谱柱（Analytical 4．6×250mm 5-Micron）;流动相为甲醇-0．4％磷酸（55／45,V/V）;流速为1．0mL／min;检测波长为360nm;柱温为40℃;进样量为20μL。结果表明,槲皮素、山奈素和异鼠李素浓度分别在2．1～21．0、1．8～18．0和0．42～4．2μg／mL范围内呈良好的线性关系,相关系数分别为：0．9999、0．9999和0．9998;槲皮素、山奈素和异鼠李素回收率分别为：97．7％、98．3％和97．6％。该方法简单、灵敏、准确,可用于牙膏中银杏叶提取物总黄酮苷含量的测定。     

异鼠李素调控AKT-FOXO1通路改善胰岛素抵抗HepG2细胞糖代谢作用机制

目的:研究异鼠李素通过AKT-FOXO1信号通路改善Hepg2细胞胰岛素抵抗机制。方法:使用四甲基偶氮唑盐微量酶反应比色(MTT)法筛选异鼠李素安全剂量;通过高浓度胰岛素处理诱导Hepg2细胞胰岛素抵抗(IR)模型;使用葡萄糖氧化酶法测得培养基中葡萄糖含量,衡量异鼠李素对胰岛素抵抗Hepg2细胞葡萄糖代谢水平影响;通过Western blot 检测细胞中AKT(蛋白激酶B),p-AKT(磷酸化的蛋白激酶B),FOXO1(叉头转录因子O亚家族1),p-FOXO1(磷酸化的叉头转录因子亚家族1),G6pase(六磷酸葡萄糖酶),PEPCK(磷酸烯醇式丙酮酸激酶)这六个蛋白表达水平的变化。结果:异鼠李素对Hepg2细胞的安全剂量为1~3.8 μg/mL;与模型组相比,低浓度异鼠李素显著的增加了胰岛素抵抗Hepg2葡萄糖消耗量(P<0.05),显著促进了胰岛素抵抗Hepg2细胞的AKT、FOXO1蛋白磷酸化(P<0.05),从而显著抑制了G6pase和PEPCK的蛋白表达(P<0.05),其作用效果与二甲双胍相当。结论:异鼠李素可有效改善胰岛素抵抗Hepg2细胞,并通过调节AKT-FOXO1信号通路达到这一作用效果。