共查询到18条相似文献,搜索用时 218 毫秒
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研究梵净山野生藤茶中二氢杨梅素的提取及体外抗氧化。采用超声波辅助法从梵净山野生藤茶中提取二氢杨梅素,以1,1-二苯基-2-苦基肼自由基(DPPH·)和羟自由基(·OH)二种不同自由基体系研究二氢杨梅素的活性清除能力。结果表明:在实验浓度范围内,二氢杨梅素清除DPPH·的能力高于芦丁,二氢杨梅素浓度达到50 mg/L时,其清除率大于Vc,达到72.58%,随着二氢杨梅素浓度的增加,其清除·OH的能力逐步提高,最高可达到55.05%。因此,梵净山野生藤茶中二氢杨梅素具有较强的抗氧化能力。 相似文献
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通过正交实验确定超声波提取藤茶中总黄酮的最佳工艺条件,用柱层析-重结晶法从藤茶中分离得到二氢杨梅素。选用L-酪氨酸、L-多巴为底物,分别测定二氢杨梅素对酪氨酸酶的单酚酶、二酚酶的抑制率。结果表明,提取的最佳工艺条件:提取溶剂是体积分数为60%的乙醇,料液比1∶30(g/mL),提取温度40℃,提取时间40 min,总黄酮得率为46.54%。柱层析-重结晶法分离纯化得到的二氢杨梅素得率为41.12%,纯度为99.12%。二氢杨梅素对单酚酶、二酚酶均有显著的抑制作用,抑制率分别可达95.87%,69.01%。 相似文献
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以藤茶为原料,水为溶剂,采用密闭式提取罐在微波加速反应系统(MARS5)中提取二氢杨梅素,研究提取温度对二氢杨梅素提取效率的影响。结果表明,在80℃以下,二氢杨梅素的提取率很低,80℃~110℃范围内,随着提取温度的提高,二氢杨梅素的提取率呈上升趋势,在110℃时达到最高。此后,随着提取温度的升高,二氢杨梅素的提取率呈下降趋势。HPLC分析结果表明,二氢杨梅素在高温水相体系发生了分解,在180℃下分解产物又进一步发生分解。所以,在本实验条件下110℃是二氢杨梅素的最佳提取温度。 相似文献
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本研究针对藤茶类保健食品建立了功效成分二氢杨梅素的超高效液相色谱-紫外检测方法.对提取条件进行了优化,确定了提取方式:以藤茶植物形式制作的保健食品采用65%乙醇加热回流提取、以藤茶粗提物配制的保健食品采用65%乙醇超声提取功效成分二氢杨梅素.对色谱条件进行了优化,确定了色谱条件:色谱柱为Acquity UPLCTM B... 相似文献
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微波辅助法大规模提取藤茶中的二氢杨梅素 总被引:4,自引:0,他引:4
研究了二氢杨梅素的微波辅助提取法和重结晶纯化法,提取实验中考虑了微波照射时间、加热时间和料液比等因素对提取率的影响,确定的最佳提取工艺条件为:微波照射时间为20 min;加热时间为50 min;料液比为1∶10,在此条件下二氢杨梅素的提取率为25.11%;纯化实验以水为结晶溶剂进行多次重结晶,结果表明可有效的除去二氢杨梅素的杂质,二氢杨梅素的含量由53.75%到95.75%。 相似文献
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二氢杨梅素的降血糖及保护肾脏损伤效果研究 总被引:1,自引:0,他引:1
以D-半乳糖为诱导剂,采用剂量递增全程腹腔注射法建立糖耐量异常动物模型。以二氢杨梅素为受试物,实验8周后,测定各实验组大鼠空腹及餐后2h血糖、胰岛素水平、尿微量白蛋白、尿素氮以及肾脏乳酸脱氢酶比活。与模型组相比,二氢杨梅素能显著降低餐后2h血糖及胰岛素水平(P<0.05),尿微量白蛋白含量及乳酸脱氢酶比活均明显降低(P<0.05),而尿素氮水平变化不明显(P>0.05)。尿微量白蛋白及乳酸脱氢酶可作为检测肾脏早期损伤的敏感指标。结果表明:二氢杨梅素可明显改善大鼠糖耐量异常状态,对肾脏早期损伤具有一定保护作用。 相似文献
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Yaping Wang Lin Chen Michael Adu-Frimpong Chunmei Wei Wen Weng Qilong Wang Xi-Ming Xu JiangNan Yu 《European Journal of Lipid Science and Technology》2021,123(6):2000369
Hyperlipidemia has become a common disease in modern society with its prevalence becoming relatively high in the world. A series of complications that accompany hyperlipidemia are seriously threatening individuals’ health. Dihydromyricetin (DMY) is a kind of polyphenol hydroxy (OH) dihydroflavonol extracted from the stems and leaves of Ampelopsis grossedentata. It has a variety of pharmacological activities. This study aims to develop a self-microemulsifying drug delivery system (SMEDDS) to improve the oral bioavailability of DMY, and to evaluate its hypolipidemic activity. The self-microemulsion drug delivery system is composed of medium chain triglyceride (MCT, oil phase), Tween 80 (emulsifier), and PEG 200 (coemulsifier). The prepared DMY-SMEDDS has stable physical and chemical properties, small droplet size (15.49 ±0.15 nm), good polydispersity index (PDI = 0.160 ± 0.010), negative zeta potential (−17.37 ± 0.09 mV), and high encapsulation efficiency (98.04 ± 0.25%). The results of in vitro dissolution and in vivo pharmacokinetics show that the prepared DMY-SMEDDS significantly improve the solubility of DMY in aqueous medium, while its oral bioavailability is 2.34 times higher than that of free drug. In conclusion, the DMY-SMEDDS prepared in this study prospectively improves the solubility and oral bioavailability of DMY also enhance the therapeutic effect. Practical Applications : This study is relevant in the sense that SMEDDS may be used as a new strategy to improve the oral bioavailability of hydrophobic drugs. This novel nanocarrier could increase (by 2.34 times) the relative bioavailability of oral DMY-SMEDDS in rats comparative to dihydromyricetin (DMY) suspension. Thus, DMY-SMEDDS may prospectively be applied in food, nutraceutical, and pharmaceutical industries in view of its biocompatible excipients and good stability. 相似文献
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Dihydromyricetin (DMY), a natural product, was used as antioxidant in ethylene vinyl acetate copolymer (EVA) in our laboratory. Oxidation induction temperature (OIT) of EVA with the antioxidant of DMY and effect of pH on OIT was measured by means of differential scanning calorimeter (DSC). The mechanism on that antioxidation of DMY in EVA is produced on basis of determination of UV–Vis absorption, nuclear magnetic resonance (NMR) and the experiment of reacting the pyrogallic (PA) and DMY, respectively, with the DPPH. The result shows that the ortho‐trihydroxyl group (B ring) in DMY has mainly antioxidative activity and hydroxyl group of 7‐position (A ring) not only displayed reversibility to acidic or alkaline medium but also affected in some extent the antioxidative ability in EVA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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以显齿蛇葡萄叶为原料,采用微波破细胞进行预处理,然后,采用热水搅拌的方法提取显齿蛇葡萄中的二氢杨梅素.通过透射电镜对显齿蛇葡萄叶细胞微观构象进行观察,探讨不同微波照射条件对植物叶片微观结构的影响来解析微波强化提取机理.结果表明:在300 W和微波预处理时间5 min或微波功率达到600 W和处理时间为2 min 时,细胞壁出现褶皱并有部分破裂,之后随着照射功率的加大以及微波预处理时间的延长,细胞壁的破裂情况越来越明显.这就说明了细胞内的极性物质在吸收微波能后温度迅速上升,导致细胞内蒸汽压也随之迅速上升,超过了细胞壁膨胀的能力,最终使得细胞壁破裂,从而使细胞内的有效成分的提取分离变得容易.这就是微波辅助提取植物胞内有效成分的提取效率大为提高的原故. 相似文献