金佛手果叶黄酮提取工艺的优化

以乙醇为浸提剂,通过单因素和多因素实验,采用响应面试验设计方法对金佛手果叶多酚最佳提取工艺进行了研究,结果表明：黄酮最佳提取条件是乙醇浓度85%,提取时间171min,提取温度81℃,此时1g金佛手果、叶粉黄酮得率分别是0.404和1.292g/100g。可靠性验证实验表明,上述提取方法的优化条件是可靠的。     

Interaction of vitamin C and flavonoids in elderberry (Sambucus nigra L.) during juice processing

A field experiment and two oxidation experiments in the laboratory were carried out. The content of the major anthocyanins, cyanidin-3-glucoside (Cy-3-G) and cyanidin-3-sambubioside (Cy-3-Sa), in the fresh fruits from the 13 cultivars were from 361 to 1266 and from 269 to 656 mg/100 g, respectively. The two minor anthocyanins, cyanidin-3-sambu-bioside-5-glucoside (Cy-3-Sa-5-G) and cyanidin-3,5-diglucoside (Cy-3.5-dG), occurred in concentrations between 5 and 47 mg/100 g. The content of ascorbic acid and quercetin in the fresh fruits of the cultivars varied from 6 to 25, and from 29 to 60 mg/100 g, respectively. Purging of the elderberry juice with N2 and/or addition of ascorbic acid reduced the oxidative degradation rate of the two major anthocyanins and quercetin. Ascorbic acid protected the anthocyanins, but not quercetin from oxidative degradation. Mixing of fruits with air during processing and even a low content of oxygen in the juice before tapping must be avoided by appropriate steps during processing. Improvement of the nutritional value of the elderberry juice and increased protection of anthocyanins against oxidative degradation may potentially be obtained by selection of cultivars with a high content of ascorbic acid.     

响应面法优化紫茉莉籽黄酮提取及其抗氧化活性研究

[目的]研究旨在采用响应面法优化紫茉莉籽黄酮的提取工艺条件,并对紫茉莉籽黄酮提取物进行体外抗氧化活性评价。[方法]在单因素实验的基础上,运用Box-Behnken响应面设计法,分析料液比、乙醇体积分数、提取时间3个自变量及其交互作用对总黄酮得率的影响,确定最佳提取工艺。通过紫茉莉籽总黄酮对DPPH自由基的清除作用来研究其抗氧化活性。[结果]结果表明,紫茉莉籽黄酮最佳提取工艺条件：乙醇体积分数75%、料液比1:35（g·mL-1）、提取时间2h,在该条件下,紫茉莉籽总黄酮得率达1.736%。紫茉莉籽黄酮对DPPH自由基具有较强的清除作用。[结论]因此,响应面法所获得的分析结果可靠,且该法高效、简单,可用作紫茉莉籽黄酮的提取;紫茉莉籽黄酮具有明显的抗氧化活性。     

黄芩黄酮浸提过程动力学模型适用性分

为考察一级一项和一级两项动力学模型对黄芩黄酮浸提过程的模拟效果,通过不同浸提温度下的黄芩黄酮浸提过程试验,采用最小二乘法回归分别计算两动力学模型的参数.结果表明:两模型对黄芩黄酮浸提过程的拟合效果都较为理想(R2>0.9800,RSD小于1.00%);但一级两项模型的快速、慢速浸提速率常数等参数随温度变化的趋势未能反映相应的物理意义.因此,一级一项动力学模型更适用于黄芩黄酮浸提过程的模拟.     

3个香蕉品种黄酮含量与果实发育成熟的关系

为了明确香蕉果实发育及成熟过程中黄酮含量变化规律,对巴西香蕉、粉蕉和皇帝蕉果实采前发育和采后成熟过程中的黄酮含量进行测定。结果表明:3个香蕉品种在果实发育成熟过程中果皮中黄酮含量均显著高于果肉中黄酮含量。从抽蕾、断蕾到采收,3个品种果皮中的黄酮含量逐渐降低,表现出与发育负相关。采前巴西蕉和黄帝蕉果肉中黄酮含量也是逐渐降低,但粉蕉果肉中黄酮含量呈先升后降的趋势。在采后成熟过程中,3个香蕉品种果皮果肉中的黄酮含量逐渐升高。且用外源乙烯和1-MCP处理后发现,香蕉果皮和果肉中的黄酮含量明显受外源乙烯诱导而增加,受1-MCP的抑制而减少,表现出与成熟正相关。     

不同光质对龙眼胚性愈伤组织类黄酮含量的影响

以龙眼胚性愈伤组织为材料,研究不同继代培养基、培养时间和光质对龙眼胚性愈伤组织生长和类黄酮含量的影响。参照前人的研究结果,龙眼胚性愈伤组织分别在含2,4-D和Ag NO3的继代培养基上交替继代培养,测定其在黑暗条件下15、20、25、30、35 d的类黄酮含量,分析其含量变化;在此基础上,分别于红光、蓝光、白光、黄光4种不同的光质下培养愈伤组织,研究不同光质对龙眼胚性愈伤组织类黄酮含量积累的影响。研究结果表明:在黑暗条件下,龙眼胚性愈伤组织在含Ag NO3培养基上培养25 d时类黄酮含量最高为1.857 0%;在不同光质处理下,光质影响类黄酮含量从高到低依次为:蓝光(8.802 3%)红光(4.659 4%)白光(4.272 4%)黄光(2.816 9%)黑暗(1.857 0%)。     

Growth response and active constituents of Cynara cardunculus plants to the number of leaves harvests

Cardoon (Cynara cardunculus) is a highly promising medicinal plant that has been used to treat several diseases, but there remains a great need for research into both the agriculture and chemical composition of the plant. For this study, cardoon was cultivated for two successive seasons (2009/2010 and 2010/2011) at the experimental farm of the Faculty of Agriculture, Cairo University. Specifically, the study investigated the effect of numerous harvests of leaves (one, two, three and four harvests/cuts) on both the growth and the active constituents of C. cardunculus plants. Both the fresh and the dry weight of the harvested leaves were measured and the active constituents, such as carbohydrate, flavonoid, polyphenol and chlorogenic acid content, were measured. It was found that as the number of harvests increased (up to three harvests) the values of these parameters also increased in both seasons.     

银杏叶有效成分的研究与资源的开发利用

银杏树是我国特产经济植物,含有多种有效成分,在医疗和保健等领域有着广泛的用途。本文对银杏的有效化学成分、影响银杏有效成分的因素、银杏的医用和保健效能及银杏中有效成分的提取与测定技术等进行分析与综述。     

Dynamic feature of flavonoids content in different organs of larch （Larix gmelinii）

Flavonoids in plants is very important in its ecological role and economic value. The dynamic features of flavonoids content in different organs of larch (Larix gmelinii) at different light and temperature conditions were investigated in this study. Results showed that the order of flavonoids content in different organs from high to low was 7.78% (stem bark)>2.79% (leaves) >1.72% (branches) >1.19% (stem xylem)and different organs had a great seasonal variation in flavonoids content, but the change of flavonoids content at different temperature was not obvious in different organs., The content of flavonoids in barck had, a positive correlation with temperature (R ²=0.75), but that in other organs had slight variation with the change of temperature. For all the tested organs, the flavonoids content in summer and autumn was approximately 3–4 times higher than in spring and winter. This is attributed to the great stress from environmental physical variables such as UV radiation, high temperature that induce the accumulation of flavonoids. The flavonoid content of sun leaves was evidently higher than that of shade leaves, and leaves at upper part of canopy had a higher flavonoids content compared with that at other parts. This result indicates that sun radiation could improve flavonoids production in leaves (R ²=0.76). The flavonoids may actively evolve in plant defenses to environmental stress, protecting larch from the damage of high temperature and radiation, and its main function is different in different organs. Foundation item: This paper is supported by the National Natural Science Foundation of China (30300271) and the Key Project of Chinese Ministry of Education (104191). Biography: WANG Wen-jie (1974-), male, Lecturer in Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Zhu Hong     

观赏植物花色基因工程的研究进展

介绍了观赏植物花色素的种类、显色影响因素、类黄酮类色素和类胡萝卜素的生物合成途径以及利用基因工程改变花色的国内外进展．同时简单阐述了花卉基因工程中存在的问题和应用前景。