共查询到20条相似文献,搜索用时 109 毫秒
1.
花生壳提取物的体外抗氧化活性研究 总被引:4,自引:1,他引:3
为研究花生壳提取物的体外抗氧化活性,测定了花生壳提取物的还原能力、抗脂质过氧化作用、抑制油脂过氧化作用以及清除超氧阴离子自由基、羟基自由基、DPPH自由基的能力,并与抗坏血酸进行了比较.结果表明,花生壳提取物具有较好的总抗氧化活性和总还原性,能抑制脂质过氧化和油脂过氧化作用以及清除自由基.它对DPPH自由基、羟基自由基、超氧阴离子自由基的IC50分别为27.82μg/ml、183μg/ml、89μg/ml.研究表明,花生壳提取物具有较强的综合抗氧化能力,是一种很有开发价值的天然抗氧化剂. 相似文献
2.
3.
4.
使用乙醇—乙酸(1∶1)回流提取方法,获得麻疯树枝叶中的香豆素类化合物,并使用液相色谱—质谱法(LC-MS)对提取物进行定性及定量分析,通过滤纸片法探究了麻疯树中的香豆素类化合物对两种细菌的体外抑菌效果,并通过肉汤微量稀释法和生长曲线法测定麻疯树提取物(Jatropha curcas Extraction,JE)对金黄色葡萄球菌和大肠杆菌的最小抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果表明:提取的香豆素类化合物中,主要成分为佛手柑内酯(Bergapten),相对含量为18.66%,在麻疯树化学成分研究中首次发现;同时还发现黄芩素(Baicalein)和野漆树苷(Rhoifolin),相对含量为2.76%和0.16%;麻疯树香豆素类化合物对金黄色葡萄球菌和大肠杆菌均有明显抑制效果;JE对金黄色葡萄球菌和大肠杆菌的MIC分别为1.56 mg/mL和3.125 mg/mL,对二者的MBC均为6.25mg/mL。 相似文献
5.
6.
《资源开发与市场》2017,(4)
利用麻疯树油脂及其叶乙醇提取物作为原料,采用正交试验方法,考察氢氧化钠浓度、皂化温度、搅拌时间对皂基总游离碱含量的影响,确定最佳皂化条件,并制得含有和不含有麻疯树叶乙醇提取物的两种皂基。配制浓度梯度为10mg/mL、15mg/mL、20mg/mL、30mg/mL的皂液,利用滤纸片法考察这两种皂基对金黄色葡萄球菌、大肠杆菌、白色念珠菌的抑菌效果。以配制浓度为50mg/mL的皂液进行家兔皮肤刺激性试验,考察对皮肤的刺激效果。结果显示:氢氧化钠浓度为12%、皂化温度为40℃、搅拌时间为15min时的条件最佳,且总游离碱含量最低为0.30%。两种皂液对白色念珠菌无抑菌效果,对金黄色葡萄球菌和大肠杆菌有明显的抑菌效果。随着浓度增加,抑菌效果呈现增强的趋势,有无麻疯树叶乙醇提取物在抑菌效果上没有明显差异。皮肤刺激性试验表明,这两种皂液对家兔皮肤有轻微刺激性,但含有麻疯树叶乙醇提取物的皂液对家兔皮肤刺激性较弱。 相似文献
7.
8种中药提取物对植物病原真菌的抑制活性 总被引:1,自引:0,他引:1
研究目的是改良植物源杀菌剂的筛选思路,降低植物源农药的毒残留,寻找效果较持久的植物源杀菌剂.通过筛选提取常见且具有强抗逆性的植株如柳、盐肤木等植物叶中活性抑菌成分,寻找低毒持效的杀菌剂.从试验数据分析得出,在粗提物质量浓度为50mg/mL时,连翘、盐肤木对3种供试植物病原菌抑制效果显著,抑制率均在65%以上,柳叶、马尾松针、臭椿、茵陈蒿的粗提物对至少两种植物病原菌的菌丝生长速率抑制率在50%以上;香槐和枫杨叶活性较低,仅对其中一种病原菌活性达到50%;柳叶、马尾松针、臭椿叶对两种病原菌气生菌丝的生长状况具有明显的抑制作用;盐肤木粗提物的抑制作用具有较好的延续性,因此连翘、盐肤木作为植物源杀菌剂具有深入研究的价值. 相似文献
8.
9.
试验结果表明,在试验海藻糖浓度范围内(5%-25%),15%的浓度有利于盐生杜氏藻的生长和分裂,最大细胞密度为4.50× 105 cell/mL,对照组(CK)仅为3.53×1O5 cell/mL.海藻糖浓度为15%时,β-胡萝卜素含量最高,为78.3 mg/g,对照组仅为56.70mg/g;海藻糖浓度为10%时,叶绿素a的含量最高,为24.19mg/g.海藻糖可降低铜胁迫对盐生杜氏藻生长的影响. 相似文献
10.
在碱性溶液(pH10.4—11.1)中,钙离子与紫尿酸铵生成橙红色的稳定络合物,在500nm处有最大吸收,钙浓度在2.5—25μg/50ml范围内符合比尔定律,表观摩尔吸光系数为1.2×10~4L·mol~(-1)·cm~(-1),桑德尔灵敏度为0.003μg/cm~2。本法快速、准确、可靠,回收率为94—104%。 相似文献
11.
12.
13.
采用树脂负载零价纳米铁(NZVI-resin)作为铁源,活化过硫酸钠,产生硫酸根自由基氧化降解偶氮染料甲基橙。考察了温度、NZVI-resin加入量、pH值及过硫酸钠的浓度等因素对甲基橙降解率的影响,并对其降解动力学规律作了初步探讨。结果表明:降解反应遵循准一级反应动力学,在pH=3.0、Fe0=0.2 g.L-1、Na2S2O8=1.33 g.L-1的条件下,30 mg.L-1的甲基橙溶液降解率为99.7%。 相似文献
14.
ABSTRACT: A one-dimensional model for heat and oxygen transport is frequently used for the estimation of primary productivity. Such a model employs free oxygen and temperature measurements at discrete time and depth intervals. In this method the eddy diffusion coefficients of heat and oxygen are assumed to be interchangeable. This method was applied to hourly data for 24-hour periods in a small temperature stratified lake. Primary productivity was simultaneously measured with the light and dark bottle method. The application of the free oxygen method resulted in unrealistic estimates of productivity. Some consideration is given to the origin of the failure in the application of this method. 相似文献
15.
16.
Karsten Klint Jensen 《Journal of Agricultural and Environmental Ethics》2007,20(6):515-532
Is it legitimate for a business to concentrate on profits under respect for the law and ethical custom? On the one hand, there seems to be good reasons for claiming that a corporation has a duty to act for the benefit of all its stakeholders. On the other hand, this seems to dissolve the notion of a private business; but then again, a private business would appear to be exempted from ethical responsibility. This is what Kenneth Goodpaster has called the stakeholder paradox: either we have ethics without business or we have business without ethics. Through a different route, I reach the same solution to this paradox as Goodpaster, namely that a corporation is the instrument of the shareholders only, but that shareholders still have an obligation to act ethically responsibly. To this, I add discussion of Friedman’s claim that this responsibility consists in increasing profits. I show that most of his arguments fail. Only pragmatic considerations allow to a certain extent that some of the ethical responsibility is left over to democratic regulation. 相似文献
17.
建立中-韩自由贸易试验区是党中央、国务院做出的重大决策,是深入贯彻党的十八大精神,在新形势下全面深化改革、扩大开放战略的重大举措。辽宁省环保产业发展起步较早,尽管近年来在全国的位次有所下滑,但在产品门类、技术、人才、关联产业以及园区化、集群化的发展模式上仍具有一定优势。面对中-韩自由贸易试验区对环境服务业战略转型的机遇和挑战,辽宁省应明确提出环保产业发展战略和目标定位,要强化政府的主导作用,加强不同环境服务分类影响研究,实施国内环境服务企业的"走出去"战略,加快环境服务业发展和战略转型的法规和政策体系建设,制定针对国内环境服务企业的扶持战略,解决战略转型的保障问题。本文以自贸区贸易效应为理论依据,根据辽宁省环保产业发展现状,探索在新时期如何利用辽宁省的区位优势不断创造市场空间,加快政府职能转变,积极推进环保产业贸易和投资便利化,强化资本、技术、人才等要素构建,加强园区建设,培育领军企业。 相似文献
18.
19.
Under steady state conditions of flow, the seepage toward a single gravity well is governed by the Laplace Equation which may be written in terms of either the hydraulic head, the pressure head or the velocity potential. Although this equation is linear, the principle of superposition cannot be applied to sum up the individual effects in the case of a multiple gravity well system due to the variation of the flow domain under the effect of one or several wells. A method is presented allowing the use of the superposition principle in a restricted form. The superposition of the decrements of the base pressure heads than the initial heads before pumping is valid. Also the decrements in the areas of the pressure head diagrams across specific vertical sections than the original areas can be summed up together. 相似文献
20.