红薯叶茎大孔树脂分离物的抑菌作用

选用AB-8大孔树脂对红薯茎叶70%乙醇提取液进行分离,以不同浓度的乙醇溶液进行洗脱,研究各洗脱物对大肠杆菌、金黄色葡萄球菌、志贺杆菌、葡枝根霉和黑曲霉的抑制效果,以苯甲酸钠和丙酸钙为对照。结果表明,采用大孔树脂分离手段可以获得抑菌作用存在显著差异的红薯茎叶各提取物。红薯茎叶中不同极性的成分的抑菌作用不同。 更多还原     

韭菜汁分离成分的抑菌作用研究

用D-101大孔树脂吸附层析法对韭菜汁进行初步分离,对韭菜原汁及其分离成分进行平板法体外抑菌实验。结果表明：韭菜汁对大肠杆菌、绿脓杆菌、金黄色葡萄球菌、痢疾杆菌等4种供试菌都有抑制作用;大孔树脂分段分离成分中,蒸馏水洗脱成分对供试菌无抑菌能力,体积分数50%乙醇洗脱前段对4种供试菌均有较强的抑菌作用,体积分数95%乙醇洗脱段对大肠杆菌、金黄色葡萄球菌有抑制作用。     

挂绿竹竹叶提取物的抗菌作用

通过正交实验得出挂绿竹竹叶最佳抑菌提取液的提取条件为料液比1∶15、乙醇浓度60%、提取温度70℃,采用抑菌圈法测定了提取液对3种供试菌的抑菌作用.结果表明,提取液对大肠杆菌的抑制作用优于其对枯草杆菌和金黄色葡萄球菌;冷冻干燥法所得的提取液的抑菌效果优于自然风干法;提取液对枯草杆菌的最小抑菌浓度为0.063%,对金黄色葡萄球菌的为0.125%,对大肠杆菌的为0.063%.竹叶提取物与细菌作用时间越长其抑菌效果越好.     

丹参提取液体外抑菌活性研究

目的 研究丹参提取液的体外抑菌作用.方法 采用常量肉汤稀释法测定最低抑菌浓度(MIC),探讨其体外抑菌作用.采用杯碟法检测丹参不同提取方式、不同灭菌方式以及改变提取液pH值对金黄色葡萄球菌抑菌活性的影响.结果 丹参醇提液对大肠埃希菌、金黄色葡萄球菌、枯草芽胞杆菌、铜绿假单胞杆菌、短小芽胞杆菌均有抑菌作用,其95%醇提液对上述菌的MIC分别为20,20,40,80,80 mg/mL,对白色念珠菌无抑菌作用.丹参醇提液对大肠埃希菌、金黄色葡萄球菌抑菌活性较强;不同灭菌方式及改变提取液pH值对金黄色葡萄球菌抑菌活性无差异.结论 丹参提取液具有一定抑菌作用.     

丹参提取液体外抑菌活性研究

目的 研究丹参提取液的体外抑菌作用.方法 采用常量肉汤稀释法测定最低抑菌浓度(MIC),探讨其体外抑菌作用.采用杯碟法检测丹参不同提取方式、不同灭菌方式以及改变提取液pH值对金黄色葡萄球菌抑菌活性的影响.结果 丹参醇提液对大肠埃希菌、金黄色葡萄球菌、枯草芽胞杆菌、铜绿假单胞杆菌、短小芽胞杆菌均有抑菌作用,其95%醇提液对上述菌的MIC分别为20,20,40,80,80 mg/mL,对白色念珠菌无抑菌作用.丹参醇提液对大肠埃希菌、金黄色葡萄球菌抑菌活性较强;不同灭菌方式及改变提取液pH值对金黄色葡萄球菌抑菌活性无差异.结论 丹参提取液具有一定抑菌作用.     

多穗柯有效成分的提取及抑菌效果研究

目的:对多穗柯叶中的黄酮类化合物的提取和抑菌作用进行了研究。方法:采用不同提取溶剂提取多穗柯的活性成分;应用二倍稀释法对大肠埃希氏菌、普通变形杆菌、金黄色葡萄球菌、粪肠球菌、藤黄八叠球菌、枯草芽孢杆菌、白色念珠球菌等供试菌种进行抑菌实验,确定最佳的提取溶剂和确定抑菌的最低浓度。结果:发现多穗柯茶叶对其中的6种供试菌种均有不同程度的抑制作用,对白色念珠球菌没有抑菌作用。不同提取液中70%乙醇提取液的抑菌作用最为明显。MIC为0.03125g/mL。     

富硒平菇的体外抑菌作用研究

通过微波和水煎两种途径,采用水提和盐提两种不同的方法,获得平菇和富硒平菇子实体浸提液,在体外条件下对6种细菌进行抑菌作用研究。结果表明:平菇和富硒平菇对巨大芽孢杆菌、金黄色葡萄球菌、沙门氏菌有很好的抑菌作用;对铜绿假单孢菌也有一定的抑菌效果;对大肠杆菌、短杆菌抑菌效果不是很明显。微波提取法提取的提取液比水煎法提取的提取液抑菌效果要好。富硒平菇对于各试验菌的抑菌效果均比平菇要好。     

白骨壤提取物抑菌活性研究

以白骨壤叶为原料,以4种常见病原菌为供试菌种,采用生物活性追踪法研究了白骨壤叶提取物的抑菌活性。利用滤纸片扩散法对白骨壤叶不同溶剂提取物进行初步抑菌试验,确定出抑菌活性成分所在部位,并对有效部位的有效成分进行纯化、定性检测和抑菌试验。结果表明,95%乙醇提取液对4种病原菌都有较强的抑菌效果,石油醚稍有抑菌作用,水提液无抑菌作用。利用大孔吸附树脂对抑菌活性较强的乙醇提取液进行进一步分离,得到2个抑菌活性组分,它们对4种试验菌的抑菌效果与浓度呈正相关关系。纯化物对4种供试菌的抑菌大小顺序为大肠杆菌>根霉>枯草芽孢杆菌>金黄色葡萄球菌,初步的定性试验结果表明,有抑菌活性的纯化物中含有生物碱、黄酮、蒽醌等。     

牛蒡提取物抑菌活性的研究

对牛蒡根茎和皮的水、50% 乙醇以及无水乙醇提取物的抑菌作用及其稳定性进行初步研究,结果表明：各种提取液对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、黑曲霉以及面包酵母菌均有一定的抑制作用,50% 乙醇提取液抑菌效果好于水提取液和无水乙醇提取液,且各种提取液中牛蒡皮的抑菌效果好于牛蒡根茎提取液,抑菌活性由大到小依次为金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、黑曲霉菌、面包酵母。提取液在酸性条件下(pH3～5)抑菌效果较好,但高温(＞ 100℃)处理和紫外光长时间(≥ 5min)照射均可降低其抑菌活性。     

不同溶剂对竹叶提取物抑菌作用的影响

比较不同溶剂提取方法对淡竹和箬竹抑菌能力的影响,采用抑菌圈法测定淡竹和箬竹不同溶剂提取物对5种供试菌的抑菌作用。结果表明,淡竹、箬竹水提取物对白色假丝酵母菌、酿酒酵母菌、大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌有抑制作用,抑制作用效果不明显;淡竹、箬竹丙酮提取物对5种供试菌均表现抑制作用,淡竹丙酮提取物抑制效果为枯草芽孢杆菌>大肠杆菌>金黄色葡萄球菌=酿酒酵母菌>白色假丝酵母菌,箬竹抑菌效果是大肠杆菌>枯草芽孢杆菌>白色假丝酵母菌>金黄色葡萄球菌>酿酒酵母菌;淡竹、箬竹乙酸乙酯提取物对5种供试菌均表现出较强的抑菌作用,淡竹乙酸乙酯提取物平均抑菌圈直径为23.7mm,箬竹平均抑菌圈直径为22.8mm。两种竹叶水提取物抑菌效果较差,丙酮、乙酸乙酯能比较有效地从竹叶中提取具有抑菌活性的化学物质,其中乙酸乙酯的提取物抑菌效果最好,说明溶剂影响竹子提取物的抑菌能力。     

黄荆精油的提取和对5种储粮害虫的致毒作用

为明确不同提取方法对黄荆精油的提取效果和黄荆精油对主要储粮害虫的毒力差异,采用水蒸气蒸馏法、二氯甲烷提取法和超临界CO2萃取法,分别从泰山黄荆(Vitex negundo)叶片和种子中提取精油,研究了水蒸气蒸馏提取的黄荆叶片精油对绿豆象、谷蠹、玉米象、锯谷盗和赤拟谷盗的毒力及杀虫作用方式。结果表明:黄荆叶片或种子中的精油均以超临界CO2萃取的提取率最高,水蒸气蒸馏的提取率最低,叶片精油的提取率前者是后者的5.39倍,但对玉米象成虫的综合毒力后者却是前者的5.95倍。水蒸气蒸馏法从黄荆叶片中获得的精油对绿豆象、谷蠹、玉米象、锯谷盗和赤拟谷盗,不仅具有很高的触杀、驱避和综合杀虫毒效,且对种群有持续控制作用,作为储粮保护剂的开发价值大。     

黄荆叶提取液抑菌作用的研究

用黄荆叶的乙醇提取物对 6种细菌、2种酵母菌、3种霉菌三大类微生物进行抑菌实验 ,得出其最低抑菌浓度 (MIC)。由结果推断出黄荆叶提取物不失为一种良好的天然抗菌剂 ,可添加于食品和药物中     

Antioxidant and antimicrobial properties of various solvent extracts from Impatiens balsamina L. stems

The antioxidant and antimicrobial activities as well as the quantity of phenolic substances of Impatiens balsamina L. stem extracts obtained with various solvent were determined in this study. All of the extracts possessed moderate antioxidant potential in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and reducing power assays. Antimicrobial activity was estimated using the cylinder-plate and agar dilution methods against four bacterial and six fungal strains. The extracts showed good antimicrobial activity especially antifungal activity against all of the tested microorganisms. The total phenolic and flavonoid contents ranged from 2.88 to 13.63 mg gallic acid equivalents/g dried extract and 0.98 to 7.87 mg quercetin equivalents/g dried extract, respectively. The results presented here indicate that the I. balsamina stem extracts have antioxidant and antimicrobial properties and are therefore a potential source of antioxidant and antimicrobial agents for the food and pharmaceutical industries. PRACTICAL APPLICATION: Our work indicates that the I. balsamina stem may be a good candidate as natural antioxidant and antimicrobial agents. It can be applied in food industry for preservation.     

Inhibition of Propionibacterium acnes lipase by extracts of Indian medicinal plants

Lipases play an important role in pathogenesis of acne by hydrolysing sebum triglycerides and releasing irritating free fatty acids in the pilosebaceous follicles. Lipase is a strong chemotactic and proinflammatory antigen. Therefore, lipase has generated a high interest as a pharmacological target for antiacne drugs. The aim of this study was to identify inhibitory effects of plant extracts on the lipase activity of Propionibacterium acnes. Colorimetric microassay was used to determine lipase activity. Extracts from Terminalia chebula and Embelia ribes showed lower IC(50) value (1 μg mL(-1) ) for lipase inhibition as compared to Vitex negundo and Picrorhiza kurroa (19 and 47 μg mL(-1) , respectively). The active component responsible for lipase inhibition was isolated. This study reports for the first time the novel antilipase activity of chebulagic acid (IC(50) : 60 μmol L(-1) ) with minimum inhibitory concentration value of 12.5 μg mL(-1) against P. acnes. The inhibitory potential of plant extracts was further confirmed by plate assay. The organism was grown in the presence of subinhibitory concentrations of extracts from P. kurroa, V. negundo, T. chebula, E. ribes and antibiotics such as clindamycin and tetracycline. Extract from T. chebula showed significant inhibition of lipase activity and number of P. acnes.     

Antimicrobial Activities of Cynara scolymus L. Leaf, Head, and Stem Extracts

ABSTRACT: Successive chloroform, ethanol, and ethyl acetate partitions of extracts from Cynara scolymus L. leaf, head, and stem were tested for their antimicrobial activity against 15 microbial species, including 7 foodborne bacterial pathogens, Bacillus subtilis, Staphylococcus aureus, Agrobacterium tumefaciens, Micrococcus luteus, Escherichia coli, Salmonella typhimurium , and Pseudomonas aeruginosa , 4 yeasts, Candida albicans, Candida lusitaniae, Saccharomyces cerevisiae , and Saccharomyces carlsbergensis , and 4 molds, Aspergillus niger, Penicillium oxalicum, Mucor mucedo , and Cladosporium cucumerinum using the disk diffusion assay technique. The leaf extract was found to be most effective against all of the tested organisms, followed by the head and stem extracts, and the ethanol fraction showed the most significant antimicrobial activity against all of the tests among 3 soluble fractions of extract, followed by the chloroform and ethyl acetate fractions. The minimum inhibitory concentrations (MICs) of extracts determined by the agar and broth dilution method ranged from 1.25 to 10.0 mg/mL. The MIC of ethanol fraction of leaf extracts was the lowest by comparison with the other 2 extracts. The MIC for fungi was at or below 2.5 mg/mL and for bacteria was at or above 2.5 mg/mL.     

芳香植物荆条叶、枝的挥发性成分分析

同时蒸馏萃取方法分别制备北京地区野生芳香植物荆条叶、枝2个部位的精油,气-质联机分析,采用计算机质谱库检索结合气相色谱保留指数二维定性的方法,共鉴定出75种化合物,其中β-甲基紫罗兰酮、对伞花-8-醇、反,反-金合欢醇、2-戊基呋喃、愈创木酚、β-大马烯酮、顺-桧烯水合物、顺-对薄菏烷-2-烯-1-醇、糠醛、苯甲醛、苯乙醛等33种组分在荆条植物化学成分研究中首次报道。荆条叶、枝的挥发性化学组成相似,多数为单萜及倍半萜类化合物。荆条叶、枝的主要挥发性成分为β-丁香烯(叶38·8%、枝31·8%),香桧烯(叶9·8%、枝5·1%)和β-金合欢烯(叶5·7%、枝5·5%)。     

Antimicrobial and antioxidant activities of Indian gooseberry and galangal extracts

The antimicrobial and antioxidant activities of Indian gooseberry (Phyllanthus emblica Linn.) and galangal (Alpinia galanga) extracts were investigated. Two different methods (disc diffusion and agar dilution methods) were employed to evaluate the antimicrobial activities of plant extracts against Staphylococcus aureus. The minimum inhibitory concentration (MIC) values of Indian gooseberry and galangal extracts were found to be 13.97 and 0.78 mg/ml and the minimum biocidal concentration (MBC) values were 13.97 and 2.34 mg/ml, respectively. The antioxidant activities of Indian gooseberry and galangal extracts, which were evaluated by the β-carotene bleaching method, were 86.4% and 70.3%, respectively. The total phenolic contents of Indian gooseberry and galangal extracts, as determined by the Folin-Ciocalteu method, were 290.4±0.7 and 40.9±0.2 mg/g plant extract (in GAE), respectively. The GC-MS analysis showed that the main compounds of galangal extract are 1,8-cineole (20.95%), β-bisabolene (13.16%), β-caryophyllene (17.95%) and β-selinene (10.56%). On the other hand, the use of high-performance liquid chromatography (HPLC) with UV detection indicated many compounds within the Indian gooseberry extract.     

山胡椒提取物的抑菌活性及其稳定性

为了解山胡椒提取物的抑菌活性和稳定性,通过抑菌实验和稳定性实验,研究了山胡椒水提物、75%乙醇提取物和乙酸乙酯提取物对5种常见食源性污染菌的抑制作用,并探讨了热处理、pH值及紫外照射对山胡椒75%乙醇提取物及乙酸乙酯提取物抑菌稳定性的影响。结果表明,3种提取物对供试菌的抑菌效果大小顺序为:乙酸乙酯提取物>75%乙醇提取物>水提物。稳定性实验表明,山胡椒提取物的热稳定性良好;pH值和紫外照射对山胡椒提取物抑菌活性有一定影响,最适pH值为5～7;紫外照射不超过10 min时抑菌活性稳定,超过30 min后抑菌活性减弱,甚至消失。     

Antimicrobial, antioxidant and phytochemical investigations of sea buckthorn (Hippophaë rhamnoides L.) leaf, stem, root and seed

The antimicrobial and antioxidant activities of crude ethanolic extract from Hippophaë rhamnoides L. (Elaeagnaceae) leaf, stem, root and seed, and their respective fractions, obtained by liquid-liquid extraction (LLE) using hexane (HF), ethyl acetate (EAF) and water (WF), were investigated. The crude extract was obtained by Pressurised Liquid Extraction (PLE), using ethanol at 100 bar and 60 °C. Antimicrobial activity was tested against food-borne and clinical microorganisms. Antioxidant activity was measured using the DPPH-radical scavenging and the ferric reducing antioxidant power (FRAP) assays. The phytochemical contents were examined by colorimetric methods. The results showed that crude extracts were active against Gram − and + strains, and that seed and root extracts were better radical scavengers than leaf and stem extracts. For all organs, the two activities tested were found to be higher in WF. These activities were correlated with the presence of phenolic compounds in active fractions. High Performance Thin Layer Chromatography (HPTLC) fingerprints confirmed presence of phenolic compounds in active extracts and fractions.     

荆条蜜酒发酵工艺的研究

以荆条蜜为原料,通过单因素及正交试验设计,确定荆条蜂蜜酒的最佳发酵工艺参数：发酵菌种为安琪葡萄酒高活性干酵母BV818、起始糖度23%、接种量0.25%、起始pH4.00、发酵温度28℃,在此工艺条件下,产品酒精度为12.4%vol,感官评分达93分;壳聚糖季铵盐用量为0.3g/L,室温条件下静置36h时,酒体透光率达98.61%。蜂蜜酒蜜香纯正,风味良好。