溶剂及pH值对皂化后辣椒碱萃取效果的影响

为优化辣椒油树脂皂化液中辣椒碱的萃取纯化条件,以辣椒油树脂为原料,通过对皂化溶液选用不同的萃取溶剂(石油醚、正己烷、乙酸乙酯、乙醚)和调节不同pH值(6.50、7.50、8.50、9.50、10.50)来确定萃取辣椒碱的最佳工艺参数,并利用GC-MS法测定不同条件下苹取液中辣椒碱类化合物与杂质的组分及其相对含量.结果表...     

基于openCV的玉米株型骨架提取研究

作物株型形态参数,一直是作物栽培及育种中所关注的指标。以粮食作物玉米的株形图像为研究对象,基于Intel公司的开源计算机视觉库OpenCV,以Microsoft Visual Studio 2008为开发平台,综合运用图像处理与分析技术,提出了一种适应玉米株形骨架提取的简便算法,并开发了玉米株型骨架提取软件。实证检验表明,该软件能实现载入一张复杂背景的玉米株形图像,经过剪切、自适应窗口等前期处理及对原始彩色图像的灰度化处理、图像分割和噪声去除等一系列的预处理,最后采用基于C#版的OpenCV(EmguCV)的一个算法提取出玉米株形的简单骨架。     

鱼腥草中黄酮类化合物提取分离方法的研究进展

黄酮类化合物是具有广泛应用前景的天然药物。鱼腥草资源丰富,可作为黄酮类化合物的主要来源之一。阐述了鱼腥草黄酮类化合物的提取、分离方法,并对各提取分离方法的利弊进行了分析;提出了鱼腥草黄酮类化合物提取分离技术的发展前景。     

微波辅助法提取剑叶龙血树茎总黄酮的工艺研究

对微波辅助法提取剑叶龙血树茎中黄酮类物质进行了研究,通过单因素及L9(34)正交实验,得到提取最佳工艺为:温度50℃,微波功率420 W,乙醇浓度90%,料液比1:10,提取时间8 min,此条件下剑叶龙血树茎总黄酮提取率为1.20%。     

锡兰肉桂无水乙醇提取物的抑菌活性

采用菌丝生长速率法和组织测定法,测定锡兰肉桂无水乙醇提取物对胡椒瘟病菌、香蕉枯萎病菌、芒果炭疽病菌和芒果蒂腐病菌的抑菌活性以及20%锡兰肉桂微乳剂对胡椒瘟病的保护作用。结果表明,锡兰肉桂无水乙醇提取物对胡椒瘟病菌具有较好的抑菌活性,在浓度1.5 mg/mL时抑菌率为91.94%,EC50为0.687 5 mg/mL;对芒果炭疽病菌的抑菌率为63.75%,但对芒果蒂腐病菌无抑菌活性。20%锡兰肉桂微乳剂对胡椒瘟病表现出较好的保护效果,当稀释100倍和50倍时抑制率分别为72.79%和78.91%。     

Comparative chemistry and insect antifeedant action of traditional (Clevenger and Soxhlet) and supercritical extracts (CO2) of two cultivated wormwood (Artemisia absinthium L.) populations

A comparison between traditional extraction techniques (hydrodistillation and organic solvent extraction) and supercritical fluid extraction was made for two different populations and crops of Artemisia absinthium L., cultivated in the field and aeroponically. The composition of the extracts, volatile and non volatile oils, was analyzed by GC-MS and HPLC-DAD, respectively. The antifeedant and phytotoxic activity of the extracts was tested on insect pests (Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi) and plants (Lactuca sativa and Lolium perenne). The supercritical extracts exhibited stronger antifeedant effects than the traditional ones (up to 8 times more active) with moderate selective phytotoxic effects on L. perenne root growth (<50% inhibition).     

Effects of planting soybean in summer fallow on wheat grain yield,total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200 m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089 kg ha⁻¹ at the 108 kg N ha⁻¹ rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.     

梨果心与果皮中多酚提取工艺的研究

多酚具有抗氧化、抗衰老等生理功能。为充分开发利用梨加工产品的副产物——梨果心与果皮中富含的多酚,本试验以鸭梨果心、果皮为材料,采用正交试验方法,研究其多酚提取的最佳工艺条件。结果表明：温度和浸提时间对果心和果皮多酚的提取效果没有显著影响;果皮多酚的提取效果受料液比、提取次数和溶剂三个因素的影响较大;果心多酚的提取效果仅受料液比的影响较大。梨果心和果皮多酚的适宜提取工艺条件为：以80%乙醇为提取溶剂,料液比为1∶15（m∶V）,提取二次,其提取液中的多酚含量可分别达到530μg·g-1和488μg·g-1。     

纤维蛋白原的5种提取方法比较研究

为了确定纤维蛋白原的最佳提取方案。本研究主要采用反复冷沉淀法、经典冷沉淀法、冷乙醇法、硫酸铵沉淀法和聚乙二醇沉淀法对猪抗凝全血进行纤维蛋白原的提取;以单次血液处理量、制备流程耗时、纤维蛋白原的浓度,是否需要添加化学试剂和所得纤维蛋白原的纯度为考察指标,确定纤维蛋白原的最佳提取方案。结果表明：反复冷沉淀法与经典冷沉淀法相比可以明显提高提取的纤维蛋白原浓度,与化学法相比,全程均采用物理方法,无需添加任何化学制剂,不存在化学制剂回收问题,纤维蛋白原纯度较高,提取的纤维蛋白原浓度符合外用纤维蛋白原质量标准。对结果综合分析可知,反复冷沉淀法是最佳的纤维蛋白原的提取方法。     

草本纤维生物提取菌株分泌的关键酶研究

为研究草本纤维生物提取菌株分泌的关键酶种类和特性,采用经典的DNS法对草本纤维生物提取菌株分泌的果胶酶、甘露聚糖酶和木聚糖酶进行系统分析。结果表明,6 个草本纤维非纤维素降解菌株均能同步产果胶酶、甘露聚糖酶和木聚糖酶;在培养的第9~11 h,菌株CBXW-3 分泌的果胶酶活力最高达123 IU/mL,其次为菌株CBXW-1 的果胶酶活力105 IU/mL;菌株CBXW-4 的甘露聚糖酶活力最高达214.2 IU/mL,其次为菌株CBXW-1 的甘露聚糖酶活力162.1 IU/mL;菌株CBXW-4 的木聚糖酶活力最高为111.4 IU/mL,其次为菌株CBXW-6 的木聚糖酶活力87.6 IU/mL。由此得出,6 个目标菌株分泌的草本纤维非纤维素降解酶系种类丰富,酶活力高,可为阐明草本纤维生物提取机理和开发微生物资源的应用价值提供科学依据。