连翘提取物的抑菌活性研究

目的研究连翘提取物的抑菌活性。方法老翘、青翘、连翘叶和连翘花用不同极性溶剂提取,得到提取物。以金色葡萄球菌、大肠杆菌和白色念球菌为代表菌种,用K-B纸片扩散法对提取物的抑菌活性进行了初步研究。结果老翘、青翘、连翘叶和连翘花不同提取物对供试菌均有一定的抑制活性,但抑菌活性与各组分浓度不呈简单的正比关系。结论连翘提取物对金色葡萄球菌、大肠杆菌和白色念球菌均有抑制作用,且连翘叶、青翘提取物的抑菌活性优于老翘和连翘花的提取物。     

青翘提取物的抑菌活性研究

目的 研究青翘提取物的抑菌活性.方法 以金色葡萄球菌、大肠杆菌和白色念球菌为代表菌种,用K-B纸片扩散法对青翘提取物的抑菌活性进行研究.结果 青翘不同提取物对供试菌均有一定的抑菌活性,其中醋酸乙酯提取物和正丁醇提取物具有较强的抑菌活性.提取物对金色葡萄球菌的抑菌活性与提取物浓度呈正比,对大肠杆菌和白色念球菌的抑菌活性与提取物浓度不呈简单的正比关系.结论 青翘不同提取物对金色葡萄球菌、大肠杆菌和白色念球菌均有抑制作用.     

大叶桉黄酮类化合物的分析及抑菌活性的研究

目的：分析大叶桉Eucalyptus robusta．Sm干燥叶中黄酮类化合物的含量，并研究其抗菌的生物活性。方法：采用紫外分光光度法测定含量，粗提物通过聚酰胺柱分离总黄酮Flavoinds，在平板培养基上比较黄酮类化合物与土霉素Oxytetracycline抑制大肠杆菌Escherichia—coil、金黄色葡萄球菌Staphylocccus aureus、蜡样芽孢杆菌Bacterium cactus的活性。结果：总黄酮含量为0．903％，提取率为4．306％，抑菌活性明显优于土霉素。结论：该植物叶作为类抗生素饲料添加剂的开发具有较高的实用及经济价值。     

商陆提取物抑菌活性评价研究

目的:探讨商陆的有效抑菌活性成分。方法:采用琼脂扩散法测定不同商陆提取物对临床常见的15株病原菌的抑菌圈;采用液体稀释法测定最小抑菌浓度。结果:商陆不同粗提物对病原菌有不同程度的抑制作用,商陆水煎液仅对不动杆菌、白假丝酵母、新生隐球菌有一定抑制作用,最小抑菌浓度分别为500.0,500.0,62.5mg.mL-1,抑菌作用不明显;多糖提取物仅对产气荚膜梭菌、痢疾志贺菌有一定抑制作用,最小抑菌浓度为60.0,7.5mg.mL-1;商陆皂苷30%乙醇提取物抑菌效果较明显、抗菌谱较广,对产气荚膜梭菌、大肠埃希菌、金黄色葡萄球菌、不动杆菌、铜绿假单胞菌、肺炎克雷伯菌、志贺菌、甲型副伤寒菌、枯草芽孢杆菌、普通变形杆菌、白假丝酵母均有抑菌作用,最小抑菌浓度范围为17.6～70.0mg.mL-1;商陆皂苷60%和90%乙醇提取物无抑菌活性。结论:商陆抑菌活性主要有效部位为极性较大的皂苷类提取物。     

大叶桉黄酮类化合物的分析及抑菌活性的研究

目的:分析大叶桉Eucalyptus robusta.Sm干燥叶中黄酮类化合物的含量,并研究其抗菌的生物活性.方法:采用紫外分光光度法测定含量,粗提物通过聚酰胺柱分离总黄酮Flavoinds,在平板培养基上比较黄酮类化合物与土霉素Oxytetracycline抑制大肠杆菌Escherichia-coil、金黄色葡萄球菌Staphylocccusaureus、蜡样芽孢杆菌Bacterium cactus的活性.结果:总黄酮含量为0.903%,提取率为4.306%,抑菌活性明显优于土霉素.结论:该植物叶作为类抗生素饲料添加剂的开发具有较高的实用及经济价值.     

海金沙提取物抑菌活性研究

目的:研究海金沙不同溶剂提取物的抑菌活性。方法:乙醇加热回流得到粗提物,并用不同极性溶剂萃取,分别用纸片法测试抑菌活性;对粗提物分别给予强酸、强碱、高温、紫外线处理,考察其稳定性。结果:海金沙的粗提取物对金黄色葡萄球菌、痢疾杆菌、大肠杆菌的最小抑菌浓度分别为0.80、.8、1.0 g/mL;乙醚和乙酸乙酯的萃取物具有最强的抑菌效果;强酸、高温、紫外线对其抑菌活性无影响;提取物对食物防腐具有一定作用。结论:海金沙具有良好的抑菌作用;抑菌活性物质主要分布于具有一定极性的乙醚和乙酸乙酯中,正丁醇:石油醚萃取对抑菌活性的贡献不大,但可作为纯化抑菌活性成分的方法;提取物对酸、高温、紫外线均有较好的稳定性,但在强碱条件下失去抑菌活性。     

青翘石油醚提取物的抑菌活性研究

目的:研究青翘石油醚提取物的抑菌活性。方法:青翘石油醚提取物以石油醚-乙酸乙酯为流动相通过硅胶柱层析得到不同极性组分。以金色葡萄球菌、大肠杆菌和白色念球菌为代表菌种,用K-B纸片扩散法对不同极性组分的抑菌活性进行了初步研究。结果:青翘石油醚提取物各极性组分对供试菌均有一定的抑制活性,但抑菌活性与各组分浓度不成简单的正比关系。结论:青翘不同极性组分对金色葡萄球菌、大肠杆菌和白色念球菌均有抑制作用。     

中草药凤尾草两种提取物的抑菌活性研究

目的 研究中草药凤尾草两种提取物的抑菌活性.方法 以蒸馏水和70％乙醇为溶剂,制备中草药凤尾草水提物和醇提物,进一步制备药液培养基,接种大肠杆菌和金黄葡萄球菌,37℃恒温振荡培养,不同培养时间下测定培养液的OD值.结果 中草药凤尾草水提物和醇提物质量浓度分别≥62.5 mg/ml和≥31.25 mg/ml时对大肠杆菌有抑制作用,水提物和醇提物质量浓度≥31.25 mg/ml时对金黄葡萄球菌均有抑制作用.结论 中草药凤尾草两种提取物对两种致病菌均有抑制作用,对金黄葡萄球菌的抑制效果更明显,醇提物抑菌效果优于水提物.     

柑橘皮提取物体外抑菌活性的研究

分别用石油醚、氯仿和乙酸乙酯萃取经甲醇浸泡后得到的柑橘皮粗提物,然后用打孔法和最低抑菌浓度法（MIC）,判断3种提取物对人类常见的3种致病菌的抑菌性。结果表明：石油醚层提取物没有明显的抑菌效果,氯仿层和乙酸乙酯出提取物对金黄色葡萄球菌和绿脓杆菌的抑菌作用很强,其抑菌圈直径均大于15mm,属于高敏感,其MIC分别都为3.13mg/ml和6.25mg/ml;只有乙酸乙酯层提取物对大肠杆菌有抑制作用,其抑菌圈为16mm,MIC为25mg/ml。     

连翘叶茶提取物的抑菌活性研究

目的研究连翘叶茶提取物的抑菌活性。方法以金色葡萄球菌、大肠杆菌和白色念球菌为代表菌种,用K-B纸片扩散法对连翘叶茶提取物的抑菌活性进行初步研究。结果连翘叶不同提取物对供试菌均有一定的抑菌活性,其中乙酸乙酯提取物和正丁醇提取物具有较强的抑菌活性。提取物对金色葡萄球菌的抑菌活性与提取物浓度成正比,对大肠杆菌和白色念球菌的抑菌活性与提取物浓度不成正比关系。结论连翘叶不同提取物对金色葡萄球菌、大肠杆菌和白色念球菌均有抑制作用。     

大叶桉叶挥发性成分的提取及分析

大叶桉是华南地区民间常用中草药,其叶水煎剂具清热解毒、消炎止痛、防腐止痒的功效,其桉叶油可用于治疗流行性感冒、上呼吸道感染和皮肤疾病.目前国内种植的大叶桉叶挥发油的化学成分还未见文献报道.     

Antimicrobial activity of Streblus asper leaf extract

Bactericidal activity was found in the 50% ethanol (v/v) extract of Streblus asper leaves. The extract possessed a selective bactericidal activity towards Streptococcus, especially to Streptococcus mutans which has been shown to be strongly associated with dental caries. The extract had no effect on cultures of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, Staphylococcus coagulase positive, Staphylococcus coagulase negative, Serratia marcescens, Klebsiella pneumoniae, Enterobacter, Pseudomonas aeruginosa, Burkholderia pseudomeallei and Candida albicans. The minimum growth inhibitory concentration and the minimum bactericidal concentration of S. asper extract against 10(8) CFU/mL of S. mutans was 2 mg/mL. The active compound is partially polar, partially heat labile, precipitated by 80% ammonium sulphate, and possesses a molecular weight larger than 10 000 Da. The potential for using S. asper extract as a natural product for controlling dental caries is discussed.     

Antibacterial activity of Harungana madagascariensis leaf extracts

Aqueous extracts of the leaf of Harungana madagascariensis were analysed phytochemically and evaluated for antimicrobial activity against strains of Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa. Glycosides, tannins, saponins, flavonoids and alkaloids were detected in the plant material. B. subtilis, E. coli and S. typhi, but not Ps. aeruginosa, showed susceptibility at MICs of 2.0 and 15.6 mg/mL; and MBCs of 2.0-3.9 mg/mL and 15.6-31.3 mg/mL, respectively, for the cold and hot extracts. Staph. aureus showed susceptibility only to the hot extract. Concentrations of 2.5-10.0 mg/mL of the cold extract killed over 7 log(10) of the test bacterial population within 30-60 min of exposure. The hot extract needed higher concentrations and longer treatment to achieve similar levels of bacterial cell killing. The results provide a rationalization for the traditional use of H. madagascariensis leaf extracts for the treatment of gastrointestinal disorders.     

Antimicrobial activity of extracts of three major plants from the Chihuahuan desert

Dilution methods were employed to determine the effect of ethanolic extracts of Agave lecheguilla Torr. (Agavaceae), Baccharis glutinosa Pers. (Compositae) and Larrea tridentata (DC.) Cov. (Zygophyllaceae) on growth of yeasts, molds and bacteria. The three extracts analyzed showed good antimicrobial activity against more than one organism. The minimal inhibitory concentration of the extracts was also determined.     

Antimicrobial activity of Polygonum equisetiforme extracts and flavonoids

Methanol, hexane, aqueous and petroleum ether extracts of the whole plant Polygonum equisetiforme did not show any activity against ten bacterial and four fungal species. The butanol crude extract and all the pooled groups of this exhibited variable patterns of antimicrobial activity. Quercetin (a flavonol) has been isolated and identified as the major constituent. The antifungal and antibacterial activity of quercetin was compared with the antibacterial drugs gentamycin, streptomycin and ampicillin and the antifungal drug miconazole nitrate. The antifungal activity of quercetin was limited to Candida tropicalis and it had a narrow antibacterial spectrum of activity. However, its activities against Enterobacter aerogenes and Escherichia coli were low grade compared with ampicillin, stretomycin and gentamycin. Quercetin-3-O-rhamnoside, quercetin-3-O-glucuronide, quercetin-3-O-arabinoside and isorhamnetin were also isolated in very low yield. They have not been reported previously in this species.     

马齿苋不同提取部位抗氧化活性的比较

目的:研究马齿苋不同提取部位的体外抗氧化活性。方法:采用苯酚-硫酸比色法测定马齿苋提取物中多糖含量,紫外分光光度法测定马齿苋提取物中总黄酮含量;在体外化学模拟条件下,采用Fenton反应法和模拟机体中黄嘌呤与黄嘌呤氧化酶反应系统分别测定马齿苋多糖、总黄酮对羟自由基和超氧阴离子自由基的清除能力。结果:用紫外分光光度法测得马齿苋多糖提取物中多糖百分含量为39.6%,黄酮提取物中总黄酮百分含量为10.51%;多糖剂量为4.53 mg/ml对O2.-的抑制率只有2.4%,与多糖比较,黄酮对O2.-和OH.均有良好的清除能力,在剂量为0.59 mg/ml时清除O2.-可达43.7%,剂量在0.59 mg/ml～4.92 mg/ml对O2.-有良好的清除作用;而两者对OH.的清除能力明显强于O2.-,多糖在剂量为0.04 mg/ml～0.49 mg/ml,对OH.的抑制率为37.0%～90.7%,黄酮提取物剂量在0.02 mg/ml～0.18 mg/ml时对OH.的抑制率为32.0%～90.2%,且均呈良好的量效关系。结论:在两种测定方法中马齿苋总黄酮的抗氧化能力明显强于多糖,表明总黄酮是马齿苋抗氧化活性的主要成分。     

Antimicrobial activity of extracts from the cell cultures of some Turkish medicinal plants

Twenty‐four callus, and eleven cell suspension, cultures were established from Turkish medicinal plants, and crude extracts prepared from them tested against microorganisms to assess their antimicrobial activities in vitro. Of the extracts tested, those belonging to the cell cultures of five of the plant species showed antibacterial activity against mainly three bacteria and a yeast. No activity was observed against herpes simplex viruses, HSV‐I and II, but an extract from Hypericum capitatum showed a slight antiretroviral activity against HIV‐I. Copyright © 1999 John Wiley & Sons, Ltd.     

蒙古黄芪中不同提取部位抗氧化活性的研究

目的:研究蒙古黄芪中不同提取部位的抗氧化活性.方法:采用生物化学发光法对蒙古黄芪的总黄酮、总皂苷以及总多糖于1.25×10~(-3)～25×10~(-3)g·L~(-1)的浓度检测其抗氧化能力.结果:蒙古黄芪的不同提物部位对3种自由基均有清除作用,而且都呈明显的量效关系.其中,总黄酮清除自由基的能力最强,不同纯度的总黄酮(55.48%TFA,0.59%TFA和0.36%TFA)清除超氧阴离子的IC_(50)分别为0.654 2,4.654 4,6.055 2 g·L~(-1),清除羟基离子的IC50分别为0.060 5,0.254 4,0.4930 g·L~(-1),清除过氧化氢的IC_(500分别为0.010 4,0.156 0,0.224 0 g·L~(-1).结论:蒙古黄芪对过氧化氢、羟基离子的清除能力明显强于超氧阴离子.总黄酮是蒙古黄芪抗氧化活性的主要成分,总皂苷和总多糖的抗氧化能力较弱.总黄酮清除自由基的能力随纯度的增高而增高,相反,总皂苷、总多糖清除自由基的能力随纯度的增高而下降.