小羽贯众提取物抗菌活性的初步研究

目的：比较小羽贯众根状茎和叶提取物体外抑菌活性。方法：牛津杯法和96孔板法,通过测定抑菌圈大小、最小抑菌浓度（MIC）和最小杀菌浓度（MBC）,比较小羽贯众根状茎和叶提取物分别对10种常见细菌的抑制作用,以及不同产地抑菌效果的比较。结果：小羽贯众的根状茎和叶的提取物对10种常见的细菌均表现出较强的抑菌活性,肺炎克雷伯氏菌对提取物最敏感。结论：小羽贯众提取物作为一种天然的抗菌物质,具有广谱抗菌效果,有较高的应用潜力和开发前景。     

小羽贯众提取物抗菌活性的初步研究

目的:比较小羽贯众根状茎和叶提取物体外抑菌活性。方法:牛津杯法和96孔板法,通过测定抑菌圈大小、最小抑菌浓度(MIC)和最小杀菌浓度(MBC),比较小羽贯众根状茎和叶提取物分别对10种常见细菌的抑制作用,以及不同产地抑菌效果的比较。结果:小羽贯众的根状茎和叶的提取物对10种常见的细菌均表现出较强的抑菌活性,肺炎克雷伯氏菌对提取物最敏感。结论:小羽贯众提取物作为一种天然的抗菌物质,具有广谱抗菌效果,有较高的应用潜力和开发前景。     

野豌豆不同提取物抑菌活性比较

探讨野豌豆茎叶、花、种子及豆荚4个部位提取物的体外抑菌作用。采用连续倍比稀释法,观察野豌豆植株不同部位不同提取物对各供试菌种的体外抑菌作用。结果表明野豌豆各部位对供试菌种的最佳活性物质提取部位是花,其次是茎叶和子。3种提取方法中,最佳的提取方法是酸水提取法,其次是去离子水提取法。     

糙苏的药用价值与开发利用

1　植物学特性及其分布糙苏 (ＰｈｌｏｍｉｓｕｍｂｒｏｓａＴｕｒｃｚ)是唇形科 (Ｌａｂｉａｔａｅ)糙苏属中的一种多年生直立草本植物 ,茎高 5 0～10 0ｃｍ ,多分枝 ,疏被下向短硬毛。叶近圆形或卵圆形 ,全为茎生叶 ,长 5～ 12ｃｍ ,先端锐尖 ,基部浅心形或圆形 ,具柄 ;苞叶较小 ,卵形 ,具短柄。轮伞花序生于主茎和分枝之上 ,其下有被毛的条状钻形苞片 ;花萼筒状 ,长约 10ｍｍ ,花萼边缘被丛毛 ;花冠通常粉红色 ,长 1～ 2ｃｍ ,上唇边缘有不整齐的小齿 ,下唇 3圆裂 ,中裂片较大 ;雄蕊 4 ,内藏 ,花丝无毛 ,无附属器。果为小坚果 ,表面无毛…     

金荞麦的抑菌活性研究

采用试管稀释法和管碟法分别研究了金荞麦(Fagopyrum dibotrys )根状茎和茎叶不同溶剂提取物对6种细菌和13种真菌的体外抑菌作用。结果显示,金荞麦对细菌和真菌均有一定的抑制作用。对细菌的抑菌效果表明:各种提取物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、苏云芽孢杆菌、卡拉双球菌都有明显的抑菌作用,但是对5406放线菌只有根乙醇提取物和茎叶水提取物有一定的抑制效果。对真菌的抑菌效果表明:各种提取物对鞭毛菌、白色念珠菌、松赤枯病菌、玉米纹枯病菌、油菜菌核病菌、玉米弯胞杆菌、小麦赤霉病菌、绿色木霉都有明显的抑菌作用。     

金荞麦的抑菌活性研究

采用试管稀释法和管碟法分别研究了金荞麦(Fagopyrum dibotrys)根状茎和茎叶不同溶剂提取物对6种细菌和13种真菌的体外抑菌作用。结果显示,金荞麦对细菌和真菌均有一定的抑制作用。对细菌的抑菌效果表明:各种提取物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、苏云芽孢杆菌、卡拉双球菌都有明显的抑菌作用,但是对5406放线菌只有根乙醇提取物和茎叶水提取物有一定的抑制效果。对真菌的抑菌效果表明:各种提取物对鞭毛菌、白色念珠菌、松赤枯病菌、玉米纹枯病菌、油菜菌核病菌、玉米弯胞杆菌、小麦赤霉病菌、绿色木霉都有明显的抑菌作用。     

19种常见中药材醇提物的体外抗菌活性筛选

为考察19种中药材乙醇提取物的体外抗临床常见致病菌的活性,该文将中药粗粉用80%乙醇浸泡提取,提取液减压浓缩制备成浸膏,采用琼脂打孔法测定提取物抑菌圈,通过微量倍比稀释法测定最低抑菌浓度(MIC)和最低杀菌浓度(MBC/MFC)。结果表明:所筛选的19种中药材乙醇提取物对不同的菌株具有不同程度的抑制作用,14种中药材乙醇提取物抗SA、EC、PA和CA的抑菌圈范围在8～27 mm之间,其中地锦草、四块瓦、三颗针、马尾黄连和土大黄的提取物抗SA、EC的抑菌圈范围在10.3～26.6 mm之间。马尾黄连、孜然、地锦草、广西莪术、穿心莲、益母草、吴茱萸、土大黄、叶上花、土连翘、凤尾草和三颗针的醇提物对MRSA和铜绿假单胞菌耐药菌均具有显著的抗微生物活性,其MIC/MBC值在391～6 250μg·m L^-1之间;地锦草、三颗针抗MRSA的最低MIC值分别为391、781μg·m L^-1,抗PA耐药菌的最低MIC值均为1 562.5μg·m L^-1;马尾黄连、孜然和三颗针的醇提物对白色念珠菌耐药菌有中等抑制作用,杀菌效果不明显。该...     

类芽孢杆菌BD3526抑菌活性物质的初步分离及性质测定北大核心CSCD

本实验以一株类芽孢杆菌BD3526为研究对象,采用丙酮浸提菌体得到抑菌活性粗品,通过Sephadex LH-20对样品进行初步纯化,结果表明粗品对藤黄微球菌CGMCC1.1848的最低抑菌浓度(MIC)为12.5 mg/m L,对金黄色葡萄球菌CGMCC1.879和单增李斯特菌CGMCC1.9136的MIC为25 mg/m L;Sephadex LH-20纯化样品对藤黄微球CGMCC1.1848的MIC为1 mg/m L,对金黄色葡萄球菌CGMCC1.879和单增李斯特菌CGMCC1.9136的MIC为2 mg/m L。样品经链霉蛋白酶处理后,活性基本消失。经加热、酸碱、胰蛋白酶、胃蛋白酶、脂肪酶、蛋白酶K处理后,活性没有明显变化。因此,类芽孢杆菌BD3526产生的是一种细菌素类的抑菌物质,该抑菌物质在食品和医疗行业有广阔的应用前景。     

金樱子茎提取物体外抑菌活性研究

采用纸片扩散法和试管稀释法,研究金樱子茎不同溶剂粗提取物对临床常见病原细菌的抑菌活性。结果表明,金樱子茎水提取物对绿脓杆菌、痢疾杆菌、大肠杆菌、变形杆菌无抑菌活性;对伤寒杆菌的最低抑菌浓度（MIC）为20 mg（生药）/mL;对金黄色葡萄球菌的MIC为10 mg（生药）/mL。金樱子茎75%乙醇提取物对绿脓杆菌、伤寒杆菌、痢疾杆菌、大肠杆菌、变形杆菌无抑菌活性;对金黄色葡萄球菌MIC为10 mg（生药）/mL。金樱子茎乙酸乙酯、氯仿、石油醚提取物对绿脓杆菌、伤寒杆菌、痢疾杆菌、大肠杆菌、金黄色葡萄球菌、变形杆菌无抑菌活性。     

墨旱莲提取物抑菌活性初步研究

对药用植物墨旱莲Eclipta prostrata提取物的抑菌活性物质进行研究。结果表明：（1）通过不同部位提取物的抑菌试验,发现只有叶和根茎含有抑菌活性物质;（2）墨旱莲提取物对金黄色葡萄球菌、大肠杆菌、枯草杆菌、藤黄球菌的最低抑菌浓度分别为0.6、2.0、0.8、1.0 g/mL,最小杀菌浓度均为1.0 g/mL,对白色念珠菌有很强的抑菌作用,但对黑曲霉无效;（3）通过不同极性溶剂的抑菌试验表明,抑细菌活性物质易溶于石油醚、乙醚等非极性溶剂,具有最佳抑细菌效果的提取溶剂为偏碱性的65%乙醇溶液;（4）墨旱莲的抑菌活性物质可能为黄酮类物质。     

Essential oils of Phlomis leucophracta,Phlomis chimerae and Phlomis grandiflora var. grandiflora from Turkey

The essential oils of three species of Phlomis from Turkey, Phlomis leucophracta, Phlomis chimerae and Phlomis grandiflora var. grandiflora have been studied. The main constituents of P. leucophracta essential oil were β-caryophyllene (20.2%), α-pinene (19.2%) and limonene (11.0%). This species also contained three diterpene derivatives, 15-isopimaradiene, manoyl oxide and epi-13-manoyl oxide that summed 1.4%. In P. chimerae the principal compounds were β-caryophyllene (31.6%), α-pinene (11.0%), germacrene D (6.1%), limonene (5.5%) and linalool (4.7%). In P. grandiflora var. grandiflora, germacrene D (45.4%), β-caryophyllene (22.8%) and bicyclogermacrene (4.9%) were among the principal derivatives.     

Chemical Composition and Phytotoxic Activity of Artemisia selengensis Turcz. Volatiles

The chemical profile and allelopathic action of the volatiles produced by Artemisia selengensis were studied. Artemisia selengensis was found to release volatile chemicals to the environment to influence other plants’ growth, which suppressed the root length of Amaranthus retroflexus and Poa annua by 50.46 % and 87.83 % under 80 g/1.5 L treatment, respectively. GC/MS analysis led to the identification of 41 compounds (by hydrodistillation, HD) and 48 compounds (by headspace solid-phase microextraction, HS-SPME), with eucalyptol (15.45 % by HD and 28.09 % by HS-SPME) being detected as the most abundant constituent. The essential oil (EO) of A. selengensis completely inhibited the seed germination of A. retroflexus and P. annua at 1 mg/mL and 0.5 mg/mL, respectively. However, eucalyptol displayed much weaker activity compared with the EO, indicating that other less abundant constituents might contribute significantly to the EO's activity. Our study is the first report on the phytotoxicity of A. selengensis EO, suggesting that A. selengensis might release allelopathic volatile agents into the environment that negatively affect other plants’ development so as to facilitate its own dominance; the potential value of utilizing A. selengensis EO as an environmentally friendly herbicide is also discussed.     

Iridoid glucosides from Phlomis tuberosa L. and Phlomis herba-ventis L

A new iridoid glucoside, 5-desoxysesamoside, was isolated from Phlomis tuberosa L. (Lamiaceae) together with three known iridoid glucosides sesamoside, shanziside methyl ester and lamalbid. Lamiide was found in P. herba-ventis ssp. pungens in high concentrations.     

Antimicrobial Activity of Aflatoxins

Antimicrobial activity of a crude aflatoxin preparation and of aflatoxin B(1) was studied. They were found inactive against common gram-positive and gram-negative bacteria at a concentration of 100 mug/ml. Both samples of aflatoxin did, however, exhibit antimicrobial activity, though narrow and limited, against various strains of Streptomyces and Nocardia. The antibiotic action of aflatoxin B(1) was confirmed by bioautogram after thin-layer chromatography. Among seven strains of microorganisms, including aflatoxin-sensitive and -resistant strains, N. asteroides IFM 8 was found to reduce aflatoxin B(1), in addition to other minor fluorescent components in the crude preparation.     

Synthetic Antimicrobial Peptides: I. Antimicrobial Activity of Amphiphilic and Nonamphiphilic Cationic Peptides

Comparative antimicrobial properties of three artificial cationic synthetic antimicrobial peptides (SAMP): (RAhaR)₄AhaβA (where R is Arg, Aha is 6-aminohexanoic acid, βA is beta-alanine), (KFF)₃K and R₉F₂ with various amphiphilic properties have been studied relative to pathogenic strains of microorganisms: Gram-negative bacteria Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, and Salmonella enterica, Gram-positive bacteria Staphylococcus aureus, and pathogenic yeast fungus Candida albicans. The selectivity index (SI) values of the peptide preparations were calculated as the ratio of the 50% cytotoxic concentration (TC₅₀) towards eukaryotic host cells to the MIC₅₀ values of the testing antimicrobial peptides. The studied SAMPs appeared to be the most active against the pathogenic yeast fungus C. albicans and the bacterial strains St. aureus and P. aeruginosa. The SI values in these cases exceed 40. Some assumed molecular interactions of the studied SAMPs on the microbial cells have been considered, and possible pathways to increase their antimicrobial activity have been suggested. The proposed SAMPs can serve as a basis for the design and synthesis of new promising synthetic antimicrobial agents.     

Antimicrobial Activity of Sodium n-Alkylsalicylates

The activities are reported of sodium salts of several n-alkylsalicylic acids against Staphylococcus aureus, Pseudomonas aeruginosa, Mycobacterium phlei, and Candida albicans. The acids had alkyl substituents of 1 to 18 carbon atoms in the 3, 4, or 5 positions relative to the carboxyl group of salicylic acid. Generally, the antimicrobial properties were typical of anionic surface-active agents although the salicylates are more potent than most of these, particularly against S. aureus.     

Antimicrobial Activity of Several Bis-Methanethiolsulfonates

We determined the inhibitory end point of a series of bis-methanethiolsulfonates, CH(3)SO(2)S(CH(2))(n)SSO(2)CH(3) (n = 2 to 6), and correlated the structures with antimicrobial activity. Eleven microorganisms were used in the evaluation, and the maximal activity occurred when the methylene chain length was five or six. The effect of CH(3)SO(2)S(CH(2))(5)SSO(2)CH(3) (PMTS) on respiration of Aerobacter aerogenes and Staphylococcus aureus was studied at various stages of their growth cycles. The effect on viability was correlated with that of respiration in the case of A. aerogenes. Respiratory inhibition caused by PMTS varied with the growth phase of both organisms, being most pronounced when the cells tested were taken during the period of transition from the log to stationary phase. The lethal effect on A. aerogenes was also greatest at this time. During the period of increased sensitivity, the antimicrobial activity of PMTS appears to be closely related to cell respiration. The delayed rate of kill otherwise observed may reflect an impairment of protein metabolism through reaction with sensitive SH groups.     

Phlomis Russeliana Lag. undPhl. Samia L.

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