共查询到20条相似文献，搜索用时 531 毫秒
1.
目的:基于体外实验和分子对接研究枫杨抑菌活性及机制。方法:以枫杨果、树皮、叶为研究对象,分别研究其水提物和醇提物(70%乙醇)对金黄色葡萄球菌、大肠杆菌、绿脓杆菌、伤寒沙门菌、化脓性链球菌、表皮葡萄球菌的抑菌活性,确定抑菌谱和最小抑菌浓度(MIC)。利用活性追踪方法,通过硅胶吸附色谱、薄层色谱等手段,分离单体化合物,并进行抑菌活性研究,选择PBP5、FabI、FabH、Fts Z 4个抑菌关键蛋白靶点,利用Systems Dock Web Site软件进行分子对接,研究其抑菌机制。结果:实验发现枫杨果的醇提物抑菌效果最好,对伤寒沙门菌最小抑菌浓度为7.81 mg/mL,首次从枫杨果中分离得到β-谷甾醇、β-胡萝卜苷、齐敦果酸,三个化合物对于PBP5、FabH、FtsZ蛋白靶点Docking score均大于7,结果活性很好。结论:枫杨果醇提物抑菌谱广、抑菌能力强,其可能是通过抑制革兰氏阳性菌细胞壁肽聚糖的合成,以及细菌脂肪酸的生物合成,干扰其生物膜的形成从而抑制细菌的生长和繁殖,从而起到广谱的抗菌效果。 相似文献
2.
3.
《科技通报》2016,(3)
目的:对鱼腥草内生真菌YX-2进行菌种鉴定,并对其抑菌代谢产物进行初步研究。方法:采用形态学观察结合ITS r DNA基因序列分析鉴定菌株;用石油醚、乙酸乙酯及正丁醇对其发酵液进行萃取,并对发酵萃取物的抑菌活性进行初步研究。结果:形态和分子鉴定结果表明内生真菌YX-2归属于镰刀菌属的尖孢镰刀菌(Fusarium oxysporum);抑菌实验表明乙酸乙酯提取物和正丁醇提取物具有较强的抑菌作用,石油醚相几乎无抑菌效果,且乙酸乙酯相优于正丁醇相,乙酸乙酯相对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌的最小抑菌浓度分别为50.00 mg/m L、50.00 mg/m L和25.00 mg/m L。结论:鱼腥草内生真菌YX-2为镰刀菌属的尖孢镰刀菌,其代谢产物抑菌效果明显,可进一步进行分离鉴定,获得单体化合物,为进一步药物开发提供前期研究和物质基础。 相似文献
4.
5.
6.
目的：观察仙人掌提取物对各种不同细菌的抑菌作用。方法：以药敏试验管碟法检测三种不同浓度仙人掌提取物（250mg/ml；200mg/ml；100mg/ml）对10种细菌的抑菌效果。结果：三种不同浓度仙人掌提取物对金黄色葡萄球菌、宋内志贺菌、鲍氏志贺菌均有明显抑制作用。 相似文献
7.
天然植物型抑菌剂的配制及抗菌性能评价 总被引：1，自引：0，他引：1
《科技风》2017,(23)
本研究的研究目的:对于天然植物型抑菌剂的配制方法及抗菌性能进行研究。研究方法:选择几种天然植物,从这些植物中提取抑菌剂,然后就这些抑菌剂的抗菌性能进行评价,选择的是豆蔻、肉桂、贯叶连翘、甘草及迭迭香等几种香辛料,然后采用无水乙醇进行提取,测定提取液对于大肠杆菌,金黄色葡萄球菌,鼠伤寒沙门氏菌等的最小抑制浓度。研究结果:经过分析表明,豆蔻提取液的MIC浓度为0.5%,肉桂的相对较少为0.2%,其他香辛料的MIC浓度均为0.5%,经过大量的实验表明,所选择的香辛料,除了豆蔻之外,其他香辛料所配置的天然植物型抑菌剂对于本研究所选择的菌种都有明显的抑菌效果,并且抑菌效率高达95%以上。 相似文献
8.
以抑菌率为度量指标,通过方差分析进行抑菌比较。结果表明：38种树林抑菌率变化于7.03%-73.66%之间。油松对金黄色葡萄球菌、刺玫蔷薇对表皮葡萄球菌、复叶槭对肺炎球菌、山皂角对猪霍乱沙门氏菌、接骨木对痢疾志贺氏菌的抑菌效果较好,表现出明显的特异性。 相似文献
10.
农药敌草快的生态毒性研究 总被引：1，自引：0，他引：1
《科技通报》2015,(11)
根据《化学农药环境安全评价试验准则》(GB/T 31270-2014)对10%除草剂敌草快进行了生态毒性研究;采用寇氏法对该农药对蜜蜂、家蚕、鸟类、鱼类、天敌赤眼蜂、蚯蚓、溞类和藻类的半数效应浓度/剂量进行了统计分析。并对其毒性做了评价。结果表明,敌草快对蜜蜂、蚯蚓和鱼类低毒,对家蚕、鸟类和溞类中毒,对藻类高毒。 相似文献
11.
12.
基于生态敏感条件的中国资源型城市去产能空间格局优化 总被引：1，自引：0，他引：1
“十三五”规划及供给侧改革背景下,资源型城市面临极大的去产能和生态保护压力。为促进矿业生态协调发展,本文基于SPSS和GIS刻画了中国212个资源型城市的矿业产能格局、生态敏感区格局及其空间耦合关系,在此基础上构建多目标优化模型,提出去产能空间格局优化方案。研究表明：①中国矿业产能分布显著集中,47.29%的产能集中于22个资源型城市;②资源型城市整体生态敏感性高,综合生态敏感区面积占比高达50.91%;③76.49%的矿业产能分布于II级和III级生态敏感区,矿业产能与生态敏感区分布不存在根本冲突;④30%的去产能目标假设下,到2020年预计削减矿业产能19.83亿t,生态避让效应达43.15%,125个资源型城市亟需去产能。其中煤炭、综合型、黑色金属和有色金属资源型城市产能削减量分别为9.55亿t、3.42亿t、2.39亿和2.43亿t;⑤建议按先南后北、先县级市后地级市原则分阶段有序调整矿业产能空间格局,科学合理推进全国资源型城市转型发展。 相似文献
13.
Savita P. Rao Patti Ratnakar P. Suryanarayana Murthy Antonino Catanzaro 《Indian journal of clinical biochemistry : IJCB》1995,10(2):77-84
The activity of a calmodulin antagonist, trifluoperazine (TFP), was testedin vitro againstMycobacterium avium (ATCC 25291). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of this compound forM. avium were 20 and 30 μg/ml, respectively. TFP was also found to completely inhibit the growth of 10 isolates ofM. avium (5 patient isolates and 5 environmental isolates) at 30 μg/ml. At near neutral pH (6.8), the MIC of TFP was found to be 20 μg/ml. However, at pH 5.5 (intracellular pH of macrophages), there was a decrease in the inhibitory activity of the compound against this organism. Interestingly, 99.6% ofM. avium within human monocyte-derived macrophages were killed at a drug concentration of 30 μg/ml, which correlates well with the MBC of TFP againstM. avium in vitro. Although the MIC for TFP appears to be higher than that forMycobacterium tuberculosis H37Rv, our studies suggest that calmodulin antagonists might be useful as drugs against infection due toM. avium. It is suggested that administration of TFP in combination with other known drugs may enhance the overall bactericidal effect. 相似文献
14.
我国抗菌植物资源研究与开发利用 总被引：3，自引：0，他引：3
我国是一个抗菌植物资源大国，资源十分丰富。抗菌植物资源的研究是对该项资源更合理、经济、有效地开发利用的措施、原则、方法的综合性研究。根据大量抗菌植物调查研究数据，本文概述了该项研究及应用的最新进展、面临的问题及采取的对策，并对其资源保护和进一步开发利提出了建议。 相似文献
15.
采用连续二倍梯度琼脂稀释法研究龙脷叶水提物和的50%、70%、95%乙醇提取物的抑菌活性,并对抑菌作用强的提取物以石油醚、乙酸乙酯、正丁醇依次萃取,测定不同极性部位的最低抑菌浓度(MIC)。结果表明,龙脷叶50%乙醇提取物的正丁醇部位对六种试验菌株明显抑制:对金黄色葡萄球菌(Staphylococcus aureus)、金黄色葡萄球菌耐药株(Methicillin resistant Staphylococcus aureus)和大肠杆菌(Escherichia coli)的MIC为15.60m g·mL-1;对铜绿假单胞菌(Pseudomonas aeruginosa)、伤寒沙门氏菌(Salmonella typhi.)和乙型副伤寒沙门氏菌(Bacillus paratyphosus B)的MIC为7.81m g·mL-1。可为进一步研究龙脷叶抑菌活性成分提供依据。 相似文献
16.
N.I. Ioakimidis 《Journal of The Franklin Institute》1984,317(1):27-33
The shape of a caustic and its initial curve about a crack in fracture mechanics for plane elastic media is defined by a pair of equations, the first of which does not in general possess a closed-form solution, being of fifth or higher degree and, frequently, transcendental. A closed-form solution of this equation is obtained on this basis and after an appropriate modification of the method of Burniston and Siewert. An application to the problem of a straight crack under tensile loading at infinity is made and the diameters of the caustic and its initial curve are evaluated analytically and numerically with excellent accuracy after the solution of an equation of fifth degree in closed-form. 相似文献
17.
P. Ratnakar P. Suryanarayana Murthy 《Indian journal of clinical biochemistry : IJCB》1995,10(1):34-38
Allicin was prepared from the ethanol extract of garlic without the use of heat. It inhibited the growth ofMycobacterium tuberculosis H37Rv andM. tuberculosis TRC-C 1193 resistant to isoniazid completely when grown as surface cultures as well as shake cultures. The minimum inhibitory concentration (MIC) was 70 μg/ml for both organisms. Further purification of allicin over silica gel-G columns gave a chloroform elutable fraction called CEF-allicin which inhibited the growth of both the susceptible and the isoniazid resistant strains ofM. tuberculosis. Its MIC is 25 μg/ml and is the lowest reported so far when compared with very high inhibitory concentration of 1 to 3mg/ml reported by other workers. It completely inhibited the synthesis of lipids and DNA from14C-acetate and3H-thymidine respectively and almost completely that of proteins and glycine derived carbohydrates from14C-glycine ofM. tuberculosis within 6 hr of exposure to CEF-allicin. 相似文献
18.
19.
P. Ratnakar P. Suryanarayana Murthy 《Indian journal of clinical biochemistry : IJCB》1996,11(1):37-41
Water extract of garlic (Allium sativum) inhibited the growth ofMycobacterium tuberculosis H37Rv andM. tuberculosis TRC-C1193 susceptible and resistant to isoniazid respectively. The minimum inhibitory concentration (MIC) was slightly above 80 but less than 160 μg/ml and slightly above 100 but less than 200 μg/ml for the susceptible and resistant strains respectively. Gel filtration in Sephadex G-100 columns showed that two protein fractions (43 & 38 kD) possessed antitubercular activity with much lower MICs of 20–40 μg/ml and 30–60 μg/ml for susceptible strain. Water extract, when added to actively growingM. tuberculosis in their mid log phase prevented their further growth. The water extract of garlic inhibited the incorporation of14C glycine into whole cells by 81% in 6 hrs. indicating that the primary mechanism of action is by inhibition of protein synthesis. 相似文献
20.
对难选镍钼多金属矿进行了湿法工艺浸出试验研究。对纯碱用量、片碱用量、浸出液固比、浸出时间、浸出温度等条件进行了试验研究,确定了各个因素最佳条件:在碱性条件下、液固比为3∶1、温度90℃条件下浸出时间3h后,钼的浸出率达96%。 相似文献