植物提取物对大豆疫霉菌抗菌活性的初步研究

采用Paper Disk法测定了云南省200种植物的提取物对大豆疫霉(Phytophthora sojae)的抑菌活性。结果表明,光叶合欢(Albizia lucidior)、白钩藤(Uncaria sessilifructus)及黄豆树(Albizia procera)的提取物在浓度为10μg/μL时有较好的抗菌活性,而在2.5μg/μL时只有黄豆树提取物显示出抗菌活性。并从黄豆树中分离出其抗菌的主要活性成分3-O-[α-L-arabinopyranosyl-(1→2)-β-D-fucopyranosyl-(1→6)-2-acetamidO-2-deoxy-β-D-glu-copyranosyl]echinocystic acid。     

77种植物提取物对植物病原菌的生长抑制作用

以稻瘟病菌(Pyricularia grisea),水稻恶苗病菌(Fusarium moniliforme),玉米大斑病菌(Exserohilum turci-cum)等12种植物病原菌为供试菌种,采用生长速率法对77种植物的95%乙醇提取物在200μg/mL下进行室内抑菌试验。结果表明有15种植物提取物对植物病原菌有抑制作用,其中华山姜、硬骨藤、龙舌兰、红蒜、大花哥纳香、海南草珊瑚对至少一种菌的抑制率在50%以上,版纳青梅、大果巴戟、华山姜等8种植物提取物对至少三种病原菌均有不同程度的抑制作用。红蒜提取物对百合炭疽病菌、海南草珊瑚提取物对番茄灰霉病菌,以及龙舌兰提取物对玉米大斑病菌的抑制率分别为61.4%、70.7%、76.6%,与阳性对照抑制率相比效果明显。     

博落回、虎杖和黄芩提取物对植物病原菌的抑制作用

研究了博落回(Macleaya cordata)、虎杖(Reynoutria japonica)和黄芩(Scutellaria baicalensis)提取物对三种植物病原细菌和六种病原真菌的抑制作用.结果显示:虎杖提取物对根癌土壤杆菌和番茄疮痂病菌表现出较强的抗细菌活性;博落回提取物表现出较强的抗真菌活性,对供试真菌的半抑制浓度(IC50)在0.04～0.76mg/mL之间.     

3种植物精油对霉菌的抑制作用

肉桂 ( Cinnamomum cassia Presl)别名连桂 ,属樟科樟属 ,常绿乔木 ,高 1 0～ 1 5m,多为栽培 ,主产于广西、广东等地 ,云南、福建等省亦有分布。人们可从其叶、枝或树皮、籽中提取精油 ,精油主要用于医药及食品香精[1 ] 。山苍子 [Litsea cubeba ( Lour.) Pers]别名山鸡椒、木姜子 ,属樟科木姜子属 ,落叶灌木和乔木 ,高 8～ 1 0 m,果期 7～ 8月份 ,我国长江以南各省都有分布。民间广泛使用水蒸汽蒸馏法 ,从其果实中提制精油 ,精油主要用于调配食品、化妆品香精 ,合成其它原料及维生素 [2 ]。丁子香 [Stzygium aromaticum( Linn.)Merr.et…     

烟草提取物对十一种植物病原真菌的抑制作用

采用菌丝生长速率法研究烟叶95%乙醇提取物和正己烷提取物对苹果腐烂病菌等11种植物病原真菌的抑菌活性,并通过液相色谱及气质联用色谱对烟叶提取物中多酚类、黄酮类、萜烯类等抑菌活性成分进行测定。实验结果表明,0.5 g/m L(工作浓度5 mg/m L)的两种溶剂提取物对11种病原真菌的菌丝生长均有抑制作用,其中对苹果腐烂病菌(V.mali)的抑制作用最强,且同浓度的正己烷提取物的抑菌活性优于95%乙醇提取物。根据不同材料提取物及几种纯物质溶液的抑菌特点,推测西柏三烯二醇可能是烟叶提取物中主要的抑菌活性物质。     

索骨丹提取物抗氧化及对乳腺癌细胞的抑制作用

探讨索骨丹提取物的抗氧化作用及体外对乳腺癌细胞生长的影响.通过自氧化方法测定索骨丹提取物对超氧阴离子的清除能力;用MTT法测定索骨丹对乳腺癌细胞的影响.结果显示,索骨丹水提取物、索骨丹鞣质及蒽醌在浓度0.5～3.0 mg·mL1范围内对超氧阴离子的抑制作用随浓度的增加而增强;索骨丹乙酸乙酯提取物对乳腺癌细胞的生长在经过48h和72h作用后最大抑制率分别为57.9％和67.7％.结果表明,索骨丹提取物具有强的抗氧化活性,并对乳腺癌细胞的生长繁殖有较强的抑制作用.     

黄柏果实提取物对植物病原真菌的抑制作用

在室内测定了芸香科植物黄柏(Phellodendron chinese Schneid.)果实乙醇粗提物及其4个不同极性溶剂的萃取部分在浓度为1 mg/mL时对小麦纹枯病菌(Rhizoctonia cerealis)、稻纹枯病菌(Rhizoctonia solani)、番茄镰刀菌萎焉病菌(Fusarium oxysporum f. sp.lycopersici)、黄瓜枯萎病菌(Fusarium oxysporum f.sp.cucumerinum)、棉花枯萎病菌(Fusarium vasinfectum)、棉花黄萎病菌(Verticillium dahliae)、小麦赤霉病菌(Fusarium graminearum)、玉米小斑病菌(Bipolaris maydis)、西瓜枯萎病菌(Fusarium oxysporum f.sp.niverum)、梨黑星病菌(Venturia piri-na)、稻瘟病菌(Magnaporthe grisea)等11种植物病原真菌的抑制作用.乙酸乙酯部分和正丁醇部分对植物病原菌均表现出较强的抑制活性,其中乙酸乙酯部分对两种丝核菌小麦纹枯病菌和稻纹枯病菌的生长抑制作用最强,抑制率分别为100.00%和89.36%;正丁醇部分对两者的抑制率分别为97.32%和61.32%.实验结果表明,黄柏果实中的抗真菌活性成分主要存在于乙醇粗提物中的乙酸乙酯和正丁醇萃取部分中.     

虎杖提取物对弹性蛋白酶的抑制作用研究

本文主要研究了虎杖提取物对弹性蛋白酶的抑制作用。实验利用热水浸渍法提取虎杖得到粗提取物1(CE1),聚酰胺柱层析后得到粗提取物2(CE2),并进行一系列的定性及定量分析。分别用紫外分光光度法和荧光光谱法研究了提取物对弹性蛋白酶的抑制作用和荧光猝灭作用。实验结果表明CE1和CE2中均含有虎杖苷,含量分别为41.01%和69.57%。CE1、CE2和虎杖苷对弹性蛋白酶有一定的抑制作用,当浓度为2.0 mg/mL时,它们对弹性蛋白酶的抑制率分别为53.56%、61.27%和82.53%。CE1、CE2和虎杖苷对弹性蛋白酶均有明显的内源荧光猝灭作用,当浓度为0.1 mg/mL时,荧光猝灭率分别为70.38%、72.90%和75.99%。     

6种植物提取物对酪氨酸酶活性的影响

近年来,中草药美容由于疗效显著、毒副作用小而风靡全球。与此同时,中外众多研究者从中国古代治疗皮肤病的方剂中筛选出多种中药,以现代实验手段探讨它们的作用机理,从而更有效地指导美容用品的研制开发,植物药对酪氨酸酶活性的影响便是其中的研究课题之一。已有证据表明,酪氨酸酶在黑色素生成过程中起着极为关键的作用,用药物调节酪氨酸酶的活性,能医治相关的皮肤病[1]。Ｙｕｋｉｍｉｔｓｕ等[2]选用26种在古方中用于皮肤增白的中药进行了酪氨酸酶活性的抑制性试验;雷铁池等[3]用计算机从古今中医治疗色素增加性皮肤病方剂中精选69首进…     

三种中药提取物对黄嘌呤氧化酶的抑制作用

分别用水、60%乙醇和95%乙醇为提取溶剂,对泽泻、青风藤和白芷进行提取,通过测定黄嘌呤氧化酶(XOD)-黄嘌呤反应体系终产物尿酸的吸光度,得出各提取物对XOD的抑制率,并判断其抑制机制。实验结果显示,在一定浓度范围内,泽泻和青风藤两种醇提物对XOD的抑制率较高,泽泻60%乙醇提取物抑制率最高达86%,青风藤95%乙醇提取物抑制率最高为71.2%,白芷水提取物对XOD抑制率较高,最高为72.7%。结果表明,三种中药的提取物均具有较强的体外抑制XOD活性的作用。     

Large-Scale Screening of the Plant Extracts for Antifungal Activity against the Plant Pathogenic Fungi

Plants produce chemicals of immense diversity that provide great opportunities for development of new antifungal compounds. In search for environment-friendly alternatives to the fungicide of current use, we screened plant extracts obtained from more than eight hundred plant materials collected in Korea for their antifungal activity against the model plant pathogenic fungus, Magnaporthe oryzae. This initial screening identified antifungal activities from the eleven plant extract samples, among which nine showed reproducibility in the follow-up screening. These nine samples were able to suppress not only M. oryzae but also other fungal pathogens. Interestingly, the plant extracts obtained from Actinostemma lobatum comprised five out of eight samples, and were the most effective in their antifungal activity. We found that butanol fraction of the A. lobatum extract is the most potent. Identification and characterization of antifungal substances in the A. lobatum extracts would provide the promising lead compounds for new fungicide.     

银杏外种皮提取物对病原菌﹙Cylindrocladium colhounii﹚的抑制作用

采用菌丝生长抑制法,研究了银杏外种皮3种不同提取物对病原菌（Cylindrocladium colhounii）的抑制作用并测定了这些提取物的MIC/MBC。结果表明,在相同实验天数内,抑菌效果（最小抑菌率）由高到低依次为银杏外种皮乙醇提取物（37.4%）、石油醚提取物（23.7%）和新鲜外种皮汁液（18.4%）。当提取物的浓度提升到一定程度时,三者的抑菌率均可达到100%;三种提取物的MIC/MBC分别为：86.25/86.25,172.5/276,293.25/345 mg·mL^-1。可见银杏外种皮具有明显抑制该病原菌生长的作用,且抑菌成分在乙醇中的溶解度较大。这为进一步研究该抑菌成分乃至生物农药的开发奠定了基础。     

三种苔藓植物提取物对植物病原菌的抑菌性研究

以立枯丝核菌(Rhizoctoniasolani)、棉花枯萎病菌(Fusariumoxysporum)、苹果轮纹病菌(Physalosporapiricolanosa)、草莓灰霉病菌(Botrytiscinerea)四种植物病原菌为供试病原菌,对大镰刀藓Drepanocladusexannulatus、锐尖匍灯藓Plagiomniumacutum和疣小金发藓Pogonatumurnigerum三种藓类醇提液进行抑菌活性筛选,结果表明,大镰刀藓提取液对立枯丝核菌有较好的抑制作用,对立枯丝核菌的EC50为0.878mg/mL;而锐尖匍灯藓的提取液对立枯丝核菌的生长却有促进作用。     

In Vitro Activity of Carbenicillin Against Gram-negative Bacilli

The activity of a new semisynthetic penicillin, carbenicillin, was determined against 241 strains of gram-negative bacilli with the tube-dilution technique. Of 143 strains of Pseudomonas sp., 99 had a minimal inhibitory concentration of 200 to 300 mug/ml. The majority of strains of Escherichia coli and Proteus spp. were sensitive to this antibiotic, with minimal inhibitory concentrations of 25 mug/ml or less. Strains of Klebsiella sp. were quite resistant to carbenicillin. The size of inoculum had no significant effect on the minimal inhibitory concentration for Pseudomonas sp.     

Evaluation of the Antiviral Activity of Extracts from Plants Grown in the Qinling Region of China Against Infection by Tobacco mosaic virus (TMV)

To investigate their antiviral potential, extracts from 126 plants grown in the Qinling region of China belonging to 103 plant species of 36 families were evaluated for antiviral activity against Tobacco mosaic virus. The activity of each plant extract on infection and replication was determined by local lesion and leaf‐disc methods. Extracts from nine species [Lactuca tatarica (Linn.) C. A. Mey, Rubus flosculosus Focke, Thermopsis lanceolata R. Br, Cotinus coggygria Scop Pulsatilla chinensis (Bunge) Regel, Thlaspi rvense Linn, Rodgersia podophylla A. Gray, Achnatherum splendens (Trin.) Nevski and Rhodiola eurycarpa (Frod.) S. H. Fu] strongly inhibited both infection and viral replication.     

60Co-r射线辐照对几种植物提取物有效成份的影响

以贯叶连翘,银杏,枳实,红车轴草,当归,灵芝,茶提取物为研究对象,采用^60Co-r辐照新技术,研究了10kGy辐照剂量对它们有效成份的影响。结果表明：辐照对贯叶连翘,银杏,枳实,红车轴草,当归,灵芝几种提取物的有效成份无明显影响;辐照后绿茶提取物中儿茶素含量较对照下降5．29％,普洱茶提取物中茶多酚含量较对照增加9．45％。     

In Vitro and In Vivo Activity of Hamycin Against Blastomyces dermatitidis

Clinical responses of patients with blastomycosis to treatment with hamycin have been variable. An explanation for this was sought in a series of studies in which in vitro and in vivo susceptibilities to hamycin of five strains of Blastomyces dermatitidis were compared. Minimal inhibitory concentrations of hamycin for the five strains indicated uniformly high levels of in vitro susceptibility (0.008 to 0.016 μg/ml). In vivo activity was measured in infected mice treated intraperitoneally for a period of 28 days with doses of the drug ranging from 0.001 to 0.030 mg per mouse. Significant differences in response to treatment among the five strains were noted (P < 0.001), and protective doses were found to vary from 0.001 to >0.030 mg per mouse per day. Further observations of infected mice after treatment revealed marked rates of relapsing infection, and several strains caused death. Persistent inapparent infections were also detected on culture of selected organs. Toxicity due to hamycin alone was not observed. These results suggest that variations in clinical responses to hamycin therapy in treatment of blastomycosis reflect differences in pathogenesis and host response in vivo to the infecting organism rather than differences in susceptibility of B. dermatitidis to hamycin.     

In Vitro Protein-Synthesizing Activity of Vesicular Stomatitis Virus-Infected Cell Extracts

Crude cytoplasmic extracts from vesicular stomatitis virus (VSV)-infected HeLa cells incorporate radioactive amino acids into hot trichloroacetic acid-precipitable material linearly for 10 to 20 min. The material synthesized in vitro corresponds in molecular weight to four of the five VSV structural proteins. However, synthesis of the viral glycoprotein (G) is significantly reduced, whereas the relative amounts of viral structural proteins L and NS synthesized are increased compared with the ratio of the proteins found in the virion. Fractionation of a VSV-infected crude cytoplasmic extract into a cytoplasmic pellet (20,000 x g for 30 min) and a cytoplasmic supernatant results in a significant reduction in protein synthesizing activity of both fractions, although both contain polysomes. The products synthesized by a cytoplasmic supernatant-directed system included all the VSV structural proteins except the glycoprotein, whereas in an in vitro system directed by the cytoplasmic pellet there is a marked reduction in synthesis of the nucleoprotein (N) and also a small relative increase in synthesis of the glycoprotein. Addition of uninfected, preincubated HeLa or L-cell S10 or a HeLa ribosomal fraction to the VSV-infected cytoplasmic pellet results in a 30- to 60-fold stimulation of (35)S-methionine incorporation. However, these uninfected extracts do not stimulate (35)S-methionine incorporation by the infected crude cytoplasmic extract or the cytoplasmic supernatant. The products synthesized by the stimulated cytoplasmic pellet now include sizeable amounts of the glycoprotein in addition to the other VSV structural proteins.