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991.
A SPE-HPLC method was developed and validated for the simultaneous determination of flavonols, isoquercitrin (1), hibifolin (2), myricetin (3), quercetin-3'-O-d-glucoside (4) and quercetin (5) in rat plasma and urine after oral administration of the total flavonoids from Abelmoschus manihot (TFA). The astragalin (6) and kaempferol (7) were used as internal standards (IS). Plasma and urine samples were pretreated by solid-phase extraction using Winchem C(18) reversed-phase cartridges. Analysis of the plasma and urinary extract was performed on YMC-Pack ODS-A C(18) and Thermo ODS-2HYEPRSIL C(18) reversed-phase column, respectively and a mobile phase of acetonitrile-0.1% phosphoric acid was employed. HPLC analysis was conducted with different elution gradients. The flow rate was 1.0 mL/min and the detection wavelength was set at 370 nm. Calibration ranges in plasma for flavonols 2-5 were at 0.011-2.220, 0.014-2.856, 0.022-4.320, and 0.028-5.600 microg/mL, respectively. In urine calibration ranges for flavonols 1, 2, 4 and 5 were at 2.00-16.00, 8.56-102.72, 2.70-21.60, and 3.00-24.00 microg/mL, respectively. The RSD of intra- and inter-day was less than 5.40% and 4.89% in plasma, and less than 3.96% and 6.85% in urine for all the analyses. A preliminary experiment to investigate the plasma concentration and urinary excretion of the flavonols after oral administration of TFA to rats demonstrated that the present method was suitable for determining the flavonols in rat plasma and urine.  相似文献   
992.
The root of Scutellaria baicalensis, called Huangqin in Chinese, is one of the most commonly used traditional Chinese medicines for the treatment of hepatitis, tumors, diarrhea, and inflammatory diseases. The major chemical constituents of Huangqin are flavonoids. In the present paper, HPLC-DAD-ESI-MS(n) was used to analyze flavonoids in the roots of S. baicalensis. A total of 26 flavonoids were identified or tentatively characterized, including 5 C-glycosides, 12 O-glycosides, and 9 free aglycones. Two C-glycosides, apigenin-6-C-glucyl-8-C-arabinoside and chrysin-6,8-di-C-glucoside, together with some O-glycosides, are reported from S. baicalensis for the first time. This method is simple, reliable and sensitive, and could be used for the quality control of Huangqin and its related preparations.  相似文献   
993.
Guo LT  Friedmann T  King CC 《Proteomics》2007,7(21):3867-3869
Many diseases of the mammalian CNS, including Parkinson's (PD) and Lesch Nyhan disease (LND), are associated with programmatic neurodegeneration or dysfunction of dopaminergic neurons in the mesencephalon, the nigrostriatal pathway, and its projections in the striatum [1-4]. Proteomic studies on brain tissue of both animal models and human PD patients have provided evidence for dysfunction and damage of many pathways, including oxidative stress-related damage, ubiquitin-proteasome dysfunction, mitochondrial energy metabolism deficiencies, and synaptic function [5-11]. To date no such proteomic studies have been reported in the related and rare basal ganglia disorder LND, a developmental rather than a neurodegenerative neurological disorder caused by deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) that regulates a major step in the purine salvage pathway [12]. Many studies have demonstrated that the both human LND patients and a mouse knockout model of HPRT deficiency have significantly reduced levels and uptake of dopamine in the striatum [4, 13-16] that is likely to be the principal cause of the CNS disorder. The precise molecular and cellular mechanisms that underlie this neurotransmitter defect are unknown.  相似文献   
994.
小麦胚芽鞘扩展蛋白特性及对水分胁迫的响应   总被引:3,自引:0,他引:3  
扩展蛋白是植物细胞壁延伸过程中的关键调节因子,在植物的生长发育以及对逆境的响应过程中起着重要作用。本文选用小麦(HF 9703)胚芽鞘为材料,采用Hepes法和SDS法分别提取小麦胚芽鞘扩展蛋白,通过改良的植物组织伸长测定仪测定其活性,并利用扩展蛋白抗体进行免疫印迹以检测其丰度,主要研究了小麦胚芽鞘扩展蛋白的特性及对水分胁迫的响应。结果表明:Hepes法提取的扩展蛋白活性较高,而SDS法的提取效率高;离体小麦胚芽鞘扩展蛋白的活性具有pH依赖性,且随缓冲液的交替更换(pH 4.5:pH 6.8)而反复逆转;扩展蛋白主要定位于细胞壁中;小麦胚芽鞘扩展蛋白和黄瓜下胚轴扩展蛋白具有交叉重组活性,但这种活性具有种属特异性。水分胁迫诱导小麦胚芽鞘扩展蛋白的活性和丰度提高,扩展蛋白活性的提高在小麦对水分胁迫的抗性方面可能具有重要作用。  相似文献   
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Li  Nan  Shi  Hangyu  Hou  Pengfei  Gao  Lu  Shi  Yongqiang  Mi  Weiyang  Zhang  Gang  Wang  Ning  Dai  Wei  Wei  Lin  Jin  Tianbo  Shi  Yongzhi  Guo  Shiwen 《Functional & integrative genomics》2022,22(1):27-33
Functional & Integrative Genomics - This study ascertained to explore the potential contribution of ARRDC3 polymorphisms in the risk and prognosis of glioma. One thousand sixty-one patients and...  相似文献   
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