超声波提取山楂叶总黄酮的工艺研究

[目的]为进一步开发利用山楂叶提供技术依据。[方法]对影响超声波提取山楂叶总黄酮的多个因子进行单因素和正交试验分析,并对超声波法和传统方法提取山楂叶总黄酮进行试验比较。[结果]70%乙醇超声波提取总黄酮得率最高。总黄酮得率在20~40min内,随提取时间的增加而明显增加,40~50 min内趋于平衡。总黄酮得率在料液比(g∶ml,下同)1∶16~1∶20时增加较快,1∶28时略有所下降。总黄酮得率在40~60℃时随着温度的升高而增大且50~60℃时增幅较大,超过60℃时随温度的升高而下降。影响总黄酮得率的主次因素依次为:乙醇浓度>超声时间>超声温度>料液比。[结论]超声波提取的最佳条件为:70%乙醇,料液比1(g)∶20(ml),温度70℃,时间50 min,2次,总黄酮的得率可高达98.87%;超声波提取总黄酮效果较好。     

酸枣仁黄酮对糖尿病大鼠肾损伤的保护作用

[目的]为了探讨酸枣仁黄酮对糖尿病大鼠肾损伤的保护作用及机制。[方法]采用腹腔注射链脲佐菌素制备糖尿病大鼠模型,连续灌胃给予酸枣仁黄酮28 d,收集大鼠尿液、血液及组织标本,检测大鼠体重、空腹血糖及肾功能、肾皮质中丙二醛(MDA)含量及超氧化物歧化酶(SOD)的活性;采用原位末端标记法(TUNEL),检测肾脏细胞凋亡。[结果]酸枣仁黄酮连续干预28 d后,与糖尿病模型组相比,大鼠体重及空腹血糖无明显变化(P>0.05),但肾功能指标明显改善,肾皮质MDA含量显著下降(P<0.05),SOD活性显著升高(P<0.05);肾脏凋亡细胞数显著减少(P<0.05,P<0.01)。[结论]糖尿病可引起肾脏高水平的氧化应激和过度的细胞凋亡。酸枣仁黄酮可通过抑制肾组织氧化应激及肾细胞凋亡而发挥肾保护作用。     

差示分光光度法在番石榴叶总黄酮提取工艺中的应用

[目的]建立番石榴叶总黄酮含量的测定方法,并对番石榴叶总黄酮提取工艺进行优化。[方法]以浓度2％的ZrOCl2·8H2O甲醇溶液为显色剂,测定波长为412nm,以芦丁为对照品绘制标准曲线,建立番石榴叶总黄酮含量的测定方法。在单因素试验的基础上,以总黄酮得率为主要考察指标,干膏收率为次要考察指标,考察料液比、乙醇浓度、提取时间和提取次数对提取效果的影响,并采用正交试验筛选出最佳提取条件。[结果]计算得线性回归方程为：Y=31．3850x-0．0255（R=0．9999）,表明在0～0．024mg／ml范围内,芦丁浓度与吸光度的线性关系良好。优化的提取工艺为：乙醇浓度40％,料液比1：20（g／ml）,提取时间1h,提取次数3次;在此条件下,番石榴叶总黄酮的提取率为3．30％,干膏得率为27．8％。[结论]差示分光光度法操作简单易行、快速、准确,适用于黄酮类化合物的含量测定。通过正交试验优选得到的番石榴叶总黄酮的提取工艺条件稳定可行,对番石榴叶总黄酮的合理开发利用提供理论依据。     

不同采收期对蓝莓抗氧化物质的影响

以蓝莓为材料,研究了不同采收期对蓝莓果实中一些重要抗氧化物质积累的影响。主要结果如下：在成熟后的7、14、21d北村和美登2种蓝莓主要活性物质花色素苷和总类黄酮含量均呈上升趋势;超氧化物歧化酶SOD活性呈上升趋势;过氧化物酶POD活性呈下降趋势。试验表明,蓝莓果实中主要活性物质含量及活性与不同采收时期有关,并且主要活性物质的含量及其活性的变化规律在两品种间一致。     

Dynamic changes of nutrient content in herbaceous peony seed

Herbaceous peony is a promising oilseed crop. ‘Hangshao’ and ‘Fenghuang Niepan’ are two cultivars with high yield and oil content. In this study, seed reserved nutrient of these two genotypes were investigated during seed development process. Results showed that ‘Hangshao’ and ‘Fenghuang Niepan’ matured approximately 85 ​d after flowering (DAF). The development process could be divided into four stages: seed formation and enlargement stage (S1), seed inclusion and enrichment stage (S2), crude fat rapid accumulation stage (S3) and dehydration and color transition stage (S4). During this process, 100-seed fresh weight (HFW) and 100-seed dry weight (HDW) increased, whereas water content (WC) decreased. HFW, HDW and WC for ‘Hangshao’ seed at 85 DAF were 28.56 g, 20.78 ​g and 37.50% respectively, whereas those for ‘Fenghuang Niepan’ seed were 27.2 ​g, 19.78 ​g, and 30.85% respectively. In terms of the primary metabolites measuring, soluble protein content was consistently low (only 2.24%–3.15%), while starch content was relatively high (5.60%–24.81%). They displayed a trend of gradual increasing in early stage, followed by rapid decline. Crude fat tended to accumulate continuously with a linear upward trend starting at 40 DAF, and its maximum level was reached at 85 DAF (27.57% for ‘Hangshao’ and 29.57% for ‘Fenghuang Niepan’). For the secondary metabolites determination, total phenols content was relatively steady, maintaining at 107.7–129.9 ​mg/g for both cultivars, while total flavonoids content varied within 25.33–65.33 ​mg/g for ‘Hangshao’ and 24.33–52.37 ​mg/g for ‘Fenghuang Niepan’. The maximum level for both cultivars occurred at 55 DAF. Furthermore, crude fat content was found to be highly correlated with WC by correlation analysis and linear regression model definition (P ​≤ ​0.01 and r ​= ​0.954). Thus, WC was recommended for evaluating crude fat in peony seed. These findings could provide scientific reference for high-yielding production practice for oleaginous peony plant.     

Quinoa flavonoids and their bioaccessibility during in vitro gastrointestinal digestion

This research evaluated the effect of in vitro gastrointestinal digestion on the bioaccessibility of flavonoid compounds present in quinoa products (seeds, sprouts, and flakes) and changes in their antioxidant activity. Flavonoids that were present after treatment with gastric and intestinal enzymes were characterized using HPLC-ESI-MS³, and the antioxidant activity was measured using two different antioxidant assays. Seven out of eleven flavonoid compounds were found intact after in vitro digestion, and their concentration were significantly increased after in vitro gastrointestinal digestion. The increase in flavonoids led to an approximately 2-fold increase in the antioxidant activity. The main class of flavonoid compounds identified in quinoa were flavonols, mainly quercetin and kaempferol glycosides. The results suggest that flavonoid compounds from quinoa products, which are associated with health benefits, are bioaccessible after efficient extraction by the digestive enzymes, and are available for further absorption in the intestine.     

薄荷叶中黄酮类物质的提取及其抗氧化活性研究

[目的]优化薄荷（Mentha haplocalyx Briq.）叶总黄酮提取工艺,并研究其抗氧化活性,为薄荷叶总黄酮的提取利用提供依据。[方法]在单因素试验基础上,以黄酮提取率为指标,采用L9（34）正交试验,对超声波辅助提取,薄荷叶中的黄酮类物质的工艺进行优选。并研究薄荷叶水提液和乙醇提取液对.OH的清除作用。[结果]薄荷叶中总黄酮的最佳工艺为：以体积分数40%乙醇为溶剂,料液比1∶30（W/V）,超声波功率400 W,提取温度50℃,提取时间40 min,此优化条件下,薄荷叶总黄酮得率达6.58%。薄荷叶水提液对.OH有较强的清除作用,且随着总黄酮含量的增加逐渐增大,最高消除率达到44.23%;薄荷叶乙醇提液对.OH的清除作用随着黄酮含量的增加先缓慢上升后持续快速下降,总体上低于薄荷叶水提液对.OH的清除作用。[结论]利用超声波协同乙醇提取薄荷叶中黄酮类物质的方法简单,可操作性强。薄荷叶中黄酮类物质对.OH有较强的清除作用,可以开发利用。     

石参中黄酮类化合物含量的测定及抗氧化活性的研究

[目的]测定石参中总黄酮含量并对其抗氧化性进行研究。[方法]采用超声波提取技术用体积分数为80％的乙醇提取石参中的总黄酮,分光光度法测定石参中的总黄酮类含量,研究石参中黄酮类化合物对超氧自由基、羟基自由基的清除作用。[结果]石参中总黄酮含量为0．7425％,石参中黄酮类化合物对自由基清除作用随着黄酮浓度的增大而表现出明显的量效关系。总黄酮浓度为9．791×10^-4mg／ml时对超氧自由基的清除率最高,为48．91％;浓度为0．0099mg／ml时对羟基自由基的清除率最高,达到83．76％。[结论]石参总黄酮对超氧自由基、羟基自由基均具有一定的清除作用。     

超声波辅助提取蚕沙中类黄酮的研究

采用超声波辅助法提取蚕沙中的类黄酮,通过单因素试验考察乙醇浓度、提取温度、处理时间对类黄酮提取率的影响。结果表明,超声波辅助提取蚕沙中类黄酮的最佳工艺条件为：乙醇浓度30％,超声波提取时间35min,提取温度70℃,此条件下蚕沙中类黄酮的提取率为2．358％。     

“促孕灌注液”中黄酮对不孕大鼠模型促排卵作用机制

为了探讨促孕灌注液中黄酮对不孕大鼠促排卵的可能机制,阐明其促进卵泡发育和促排卵的作用环节;将32只不孕模型大鼠分为克罗米芬组、黄酮组、模型组,正常大鼠10只为对照组,分别测定各组大鼠子宫及卵巢增量、卵泡发育情况、血清中促黄体素和促卵泡生成素的含量。研究结果表明,促孕灌注液中黄酮能明显增加大鼠卵巢、子宫质量,有利于卵泡的发育和排卵;能明显增加卵巢各级卵泡总数和子宫内膜厚度;能明显提高大鼠血清促卵泡刺激素FSH和促黄体生成素LH的水平,以改善大鼠内分泌机能,促进卵泡的发育和排卵。所以促孕灌注液中黄酮可以有效促进不孕大鼠的排卵作用。