中药植物金线吊乌龟对植物病原真菌的抗菌活性

采用菌丝生长速率法测定了中药植物金线吊乌龟块根甲醇提取物对5种植物病原真菌的抗菌活性,结果表明:金线吊乌龟块根提取物对梨锈病菌、稻瘟病菌、水稻纹枯病菌和玉米炭疽病菌有很高的抑制活性,质量浓度为10g/L时,抑菌率分别为97.74%、100.00%、94.51%和84.40%;有效中浓度(EC50)分别为0.5879、0.3122、0.2807g/L和0.8353g/L。对柿角斑病菌的活性较低,在10g/L质量浓度下,抑菌率只有67.59%,EC50为1.3491g/L。金线吊乌龟块根提取物对甘蔗凤梨病菌孢子、柑橘疮痂病菌孢子和梨锈病菌孢子的萌发具有明显的抑制活性,质量浓度为10g/L时,抑制率分别为91.80%、97.00%和100.00%;对西瓜枯萎病菌孢子萌发的抑制效果比较差,抑制率仅为20.63%。按生物碱分离程序对金线吊乌龟块根提取物进行初步分离,结合活性跟踪,发现氯仿层生物碱是金线吊乌龟的主要抗菌活性成分。     

Dehydro-alpha-lapachone isolated from Catalpa ovata stems: activity against plant pathogenic fungi

The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1).     

伞形花内酯对植物病原真菌的抑制作用

[目的]研究伞形花内酯对桃褐腐病菌、棉花红腐病菌、草莓灰霉病菌、辣椒炭疽病菌的抑制活性,探究其对前两种病菌的抑菌机理。[方法]采用生长速率法测定伞形花内酯对4种植物病原真菌的抑制活性;采用二倍稀释法测定最小抑菌浓度和孢子萌发率;采用扫描电镜和透射电镜观察伞形花内酯对前两种病原菌超微结构的破坏。[结果]伞形花内酯对前两种植物病原菌具有较强的抑制作用,它们的MIC为250μg/mL和500μg/mL。后两种植物病原菌的MIC分别为1 000、2 000μg/mL。在伞形花内酯的作用下,菌丝外观出现变形、内容物外溢。菌丝内部出现空腔,细胞器降解,胞质凝集、出现流失,细胞结构遭到破坏,致使细胞死亡。[结论]伞形花内酯具有较强的抗菌活性,具有作为植物源杀菌剂的开发潜力。     

雷帕霉素对4种植物病原真菌的抑菌活性

采用菌丝生长速率法,测定了雷帕霉素对番茄灰霉病菌、油菜菌核病菌、水稻纹枯病菌和棉花枯萎病菌的抑菌活性,比较了嘧菌酯、丙烷脒及雷帕霉素对番茄灰霉病菌的抑菌效果,并通过电子显微镜观察了雷帕霉素对番茄灰霉病菌菌丝生长的影响。结果表明:雷帕霉素对供试4种植物病原真菌菌丝均表现出了极强的抑制活性,其中对油菜菌核病菌的抑制作用最强,EC50值为2.23×10-4μg/mL,对番茄灰霉病菌、水稻纹枯病菌和棉花枯萎病菌的EC50值分别为1.32×10-3、4.05×10-3及3.82×10-3μg/mL;雷帕霉素对番茄灰霉病菌菌丝的抑制活性显著高于嘧菌酯(EC50值为3.24μg/mL)和丙烷脒(EC50值为3.81μg/mL)。电镜观察发现,经雷帕霉素处理后,番茄灰霉病菌菌丝表现出提前衰老等症状。研究结果可为深入探讨雷帕霉素对植物病原真菌的作用机制奠定基础。     

Screening extracts of Achyranthes japonica and Rumex crispus for activity against various plant pathogenic fungi and control of powdery mildew

Methanol extracts of fresh materials of 183 plants were screened for in vivo antifungal activity against Magnaporthe grisea, Corticium sasaki, Botrytis cinerea, Phytophthora infestans, Puccinia recondita and Erysiphe graminis f sp hordei. Among them, 33 plant extracts showed disease-control efficacy of more than 90% against at least one of six plant diseases. The methanol extracts of Achyranthes japonica (whole plant) and Rumex crispus (roots) at concentrations greater than 11 g fresh weight of plant tissue per litre of aqueous Tween 20 solution effectively controlled the development of barley powdery mildew caused by E graminis f sp hordei in an in vivo assay using plant seedlings. At a concentration of 300 g fresh weight of plant tissue per litre of Tween 20 solution, the two extracts were as efficient as the fungicide fenarimol (30 mg litre(-1)) and more active than the fungicide polyoxin B (100 and 33 mg litre(-1)) against Sphaerotheca fuliginea on cucumber plants in glasshouse trials.     

短短芽胞杆菌对植物病原真菌的抑菌活性和抑菌机理

为探讨短短芽胞杆菌菌株011对植物病原真菌的防控效果,采用平皿打孔法测定菌株011粗提液对14种植物病原真菌的抑制作用,并以番茄早疫病为研究对象,研究了其抑菌机理。结果显示,菌株011粗提液对14种病原真菌均有抑菌活性,其中对番茄早疫病菌的抑菌活性最强,抑菌率达45.9%;菌株011粗提液能导致番茄早疫病菌菌丝生长异常,抑制孢子萌发;对番茄早疫病菌菌丝生长的EC50为71.4 mg/m L,对孢子萌发的EC50和MIC分别为0.12 mg/m L和0.8 mg/m L;该粗提液能引起番茄早疫病菌菌丝的脂质过氧化程度和细胞内过氧化氢含量上升,菌丝细胞膜的蛋白质合成量下降,当粗提液浓度高于50 mg/m L时,菌丝细胞膜的麦角甾醇合成量下降;该粗提液还能降低番茄早疫病菌胞外果胶酶和纤维素酶的活性。研究表明,菌株011粗提液可作为生防制剂应用于植物病原真菌的防治。     

2种昆虫病原线虫共生菌的代谢产物对苹果病原菌真菌的抑菌作用

嗜线虫致病杆菌(Xenorhabdus nematophila HB310)和发光杆菌(Photorhabdus luminescens HB140)是分别从小卷蛾斯氏线虫和异小杆线虫中分离到的2株昆虫病原线虫共生菌。为了明确这2种共生菌的抑菌活性,分别测定了其对苹果上6种主要病原真菌的抑菌活性。结果表明,这2种共生菌对6种苹果病原真菌均有不同程度的抑制作用。嗜线虫致病杆菌HB310菌株发酵液对苹果轮纹病病原菌抑制效果最好,抑制率达76.9%,对其他病原菌的抑制作用依次为苹果树腐烂病病原菌(74.1%)>苹果斑点落叶病病原菌(60.9%)>苹果灰霉病病原菌(46.7%)>苹果青霉病病原菌(44.5%)>苹果炭疽病病原菌(23.0%);发光杆菌HB140菌株发酵液对苹果灰霉病病原菌的抑制作用最好,抑制率达到86.7%,对其他病原菌的抑制作用依次为苹果树腐烂病病原菌(76.6%)>苹果轮纹病病原菌(58.8%)>苹果斑点落叶病病原菌(46.0%)>苹果青霉病病原菌(44.2%)>苹果炭疽病病原菌(39.9%)。2种共生菌发酵液对苹果轮纹病菌均有较强的抑制作用,其EC50分别为42.28和42.92 mL/L。     

从子囊菌炭球菌中分离的活性成分L-696,474和cytochalasin D对植物病原真菌的活性

在我国云南省高等真菌中寻找新的天然农用抗真菌活性物质时,发现炭球菌子实体甲醇提取物具有较强的离体抗真菌活性。采用生物活性追踪和化学分离相结合的方法,从中分离得到2个具有较强农用抗真菌活性化合物,经红外、质谱、氢谱和碳谱确定其为L-696,474和cytochalasin D。在离体和活体条件下分别测定了L-696,474和cytochalasin D对10种植物病原菌的菌丝抑制率和2种植物病原菌的孢子萌发率,并评价了其对小麦白粉病的治疗和保护作用。结果表明:小麦纹枯病菌、油菜菌核病菌对L-696,474最为敏感,浓度为10μg/mL时菌丝抑制率分别为83.5%和82.9%;小麦赤霉病菌、小麦全蚀病菌、油菜菌核病菌、小麦叶枯病菌和苹果炭疽病菌对cytochalasin D最为敏感,浓度为10μg/mL时菌丝抑制率分别为83.6%、82.4%、81.9%、80.5%和79.7%。L-696,474和cytochalasin D在200μg/mL时完全抑制苹果炭疽病的孢子萌发;在500μg/mL时对小麦白粉病10天后的治疗作用分别为74.3%和85.7%,保护作用为67.1%和79.5%。     

Inhibitory activity against plant pathogenic fungi of extracts from Myoporum bontioides A. Gray and indentification of active ingredients

BACKGROUND: In order to understand the bioactivity of Myoporum bontioides A. Gray against plant pathogens and determine its active ingredients, the inhibitory activities of methanol extracts from M. bontioides against Fusarium oxysporum f. sp. niveum (E. F. Smith) Snyder & Hansen, Pestalotia mangiferae P. Henn., Thielaviopsis paradoxa (De Seynes) v. Hohnel, Colletotrichum musae (Berk. & M. A. Curtis) v. Arx, Alternaria alternata (Fr.) Keissler, Mycosphaerella sentina (Fr.) Schroter and Sphaceloma fawcettii Jenk. were evaluated using a growth rate method, and the active ingredient was isolated by activity-directed isolation and identified by determination and analysis of IR, (1)H NMR, (13)C NMR and mass spectra and correlative physical constants. RESULTS: The results showed that the extracts from stems and leaves of M. bontioides exhibited inhibitory activity against the seven fungi, with > 58% inhibition at 10 g L(-1) after 72 h. The active compound was isolated and identified as (-)-epingaione, and showed inhibitory activity against the above seven fungi. The inhibitory activity against P. mangiferae was the highest, with an EC(50) value of 77 mg L(-1). The EC(50) values against the other six fungi were 147-245 mg L(-1). (-)-Epingaione also inhibited spore germination of F. oxysporum f. sp. niveum, T. paradoxa and S. fawcettii.CONCLUSION: (-)-Epingaione demonstrated broad-spectrum inhibitory activity against plant pathogenic fungi and is promising for exploitation as a fungicide.     

嗜线虫致病杆菌SN313的次生代谢产物及其抑制植物病原真菌活性研究

通过化学与生物活性筛选从土壤中分离得到一株菌株,利用16S rDNA方法将其鉴定为嗜线虫致病杆菌Xenorhabdus nematophila并命名为SN313。采用微生物发酵、液相萃取、柱层析及半制备高效液相色谱等技术,对SN313的发酵液进行分离纯化,得到3个化合物。利用质谱和核磁共振等波谱技术并依据文献数据确定了这3个化合物分别是N-(2-羟基苯基乙酰) 色胺 ( 1 )、吩嗪-1-羧酸 ( 2 ) 和环(脯氨酸-色氨酸) ( 3 ),其中化合物 1 是一个新的β-吲哚基乙胺类衍生物。通过微量稀释法测定了3个化合物对4种植物病原真菌的抑制活性。结果表明:化合物 1 对辣椒疫霉Phytophthoa capsici和番茄灰霉病菌Botrytis cinerea具有明显的抑制作用 (IC₅₀值分别为11.20 μg/mL和28.94 μg/mL);化合物 2 对番茄灰霉病菌、辣椒疫霉、水稻纹枯病菌Thanatephorus cucumeris和小麦根腐病菌Bipolaris sorokiniana有明显的抑制作用 (IC₅₀ < 40 μg/mL);化合物 3 对番茄灰霉病菌具有较好的抑制效果 (IC₅₀ = 41.58 μg/mL)。从土壤微生物中获取化合物 2 ,为生物农药申嗪霉素有效成分的天然获取提供了一种新的途径。     

Structure–biological activity relationships in triterpenic saponins: the relative activity of protobassic acid and its derivatives against plant pathogenic fungi

BACKGROUND: Triterpenic saponins from Sapindus mukorossi Gaertn. and Diploknema butyracea JF Gmelin were evaluated for in vitro antifungal activity against four phytopathogenic fungi. The study of the structure–antifungal activity relationships of protobassic acid saponins was widened by including semi‐synthetic derivatives. RESULTS: Diploknema butyracea saponins exhibited significant antifungal activity against three fungi (ED₅₀ 230–455 µg mL^?1), whereas S. mukorossi saponin was effective against two fungi (ED₅₀ 181–407 µg mL^?1). The n‐butanol extract after preparative HPLC separation provided two saponins from D. butyracea saponin mixture: 3‐O‐[β‐D ‐glucopyarnosyl‐β‐D ‐glucopyranosyl]‐16‐α‐hydroxyprotobassic acid‐28‐O‐[arabinopyranosyl‐glucopyranosyl‐xylopyranosyl]‐arabinopyranoside (MI‐I), and 3‐O‐β‐D ‐glucopyranosyl‐glucopyranosyl‐glucopyranosyl‐16‐α‐hydroxyprotobassic acid‐28‐O‐[arabinopyranosyl‐xylopyranosyl‐arabinopyranosyl]‐apiofuranoside (MI‐III). The single saponin extracted from S. mukorossi saponin mixture was identified as 3‐O‐[O‐acetyl‐β‐D ‐xylopyranosyl‐β‐D ‐arabinopyranosyl‐β‐D ‐rhamnopyranosyl] hederagenin‐28‐O[β‐D ‐glucopyranosyl‐β‐D ‐glucopyranosyl‐β‐D ‐rhamnopyranosyl] ester (SM‐I). Monodesmosides resulting from the partial degradation of hederagenin and hydroxyprotobassic acid bisdesmosides exhibited significant reduction in antifungal effect. Further removal of sugar moiety yielded complete loss in activity. The antifungal activity of the triterpenic saponins was associated with their aglycone moieties, and esterification of the hydroxyl group led to change in antifungal activity. CONCLUSION: Sapindus mukorossi saponin, which is effective against Rhizoctonia bataticola (Taub.) Briton Jones and Sclerotium rolfsii Sacc., can be exploited for the development of a natural fungicide. A sugar moiety is a prerequisite for the antifungal activity of triterpenic saponin. Copyright © 2010 Society of Chemical Industry     

Comparative antifungal activities and biochemical effects of monoterpenes on plant pathogenic fungi

The antifungal activity of twelve monoterpenes, camphene, (R)-camphor, (R)-carvone, 1,8-cineole, cuminaldehyde, (S)-fenchone, geraniol, (S)-limonene, (R)-linalool, (1R,2S,5R)-menthol, myrcene and thymol was evaluated against four plant pathogenic fungi Rhizoctonia solani, Fusarium oxysporum, Penecillium digitatum and Asperigallus niger by using mycelial growth inhibitory technique. (S)-limonene and thymol were examined for their inhibitory effects on pectin methyl esterase (PME), cellulase and polyphenol oxidase (PPO) of tested fungi. Thymol was the most potent antifungal compound against the four test fungi with EC₅₀ values of 33.50, 50.35, 20.14 and 23.80 mg/L on R. solani, F. oxysporum, P. digitatum and A. niger, respectively. The antifungal activity of thymol was comparable to a reference fungicide, carbendazim. (S)-limonene and 1,8-cineole exhibited pronounced antifungal activity against the four tested fungi. The most effective antifungal compounds thymol and (S)-limonene showed strong inhibitory effect on the activity of PME and cellulase but revealed no inhibitory effect on PPO. The results showed that PME was more sensitive than cellulase to thymol and (S)-limonene. This is the first report on the inhibitory effects of monoterpenes thymol and (S)-limonene on PME, cellulase and PPO. The results indicated that monoterpenes may cause their antifungal activity by inhibiting PME and cellulase. The strong antifungal activity of thymol, (S)-limonene and 1,8-cineole reported in this study indicated that these compounds have a potential to be used as fungicides.     

Isolation and antifungal activity of kakuol, a propiophenone derivative from Asarum sieboldii rhizome

An antifungal substance active against Colletotrichum orbiculare (Berk & Mont) Arx was isolated from the methanol extracts of Asarum sieboldii (Miq) Maek rhizomes. High-resolution MS, NMR and UV spectral data confirmed that the antifungal substance is kakuol, 2-hydroxy-4,5-methylenedioxypropiophenone. Colletotrichum orbiculare was most sensitive to kakuol, with MIC of 10 microg ml(-1). Kakuol also completely inhibited the mycelial growth of Botrytis cinerea Pers ex Fr and Cladosporium cucumerinum Ellis & Arthur at 50 microg ml(-1) and 30 microg ml(-1), respectively. However, no antimicrobial activity was found against yeast and bacteria even at 100 microg ml(-1). Kakuol exhibited a protective activity against the development of anthracnose disease on cucumber plants. The control efficacy of kakuol against the anthracnose disease was in general somewhat less than that of the commercial fungicide chlorothalonil. This is the first report to demonstrate in vitro and in vivo antifungal activity of kakuol against C. orbiculare infection.     

In vitro and in vivo antifungal activity of synthetic pure isothiocyanates against Sclerotinia sclerotiorum

BACKGROUND: Isothiocyanates (ITCs) released by the enzymatic hydrolysis of glucosinolates in the Brassicaceae are potentially useful for controlling fungal pathogens. In vitro activity of pure ITCs against Sclerotinia sclerotiorum (Lib.) de Bary was studied by adding them to glass filters in petri dishes and dissolving them in the growing media. RESULTS: Methyl, allyl and benzyl ITCs were the most fungitoxic of the compounds in bioassays with S. sclerotiorum isolate Ss31. In the volatile phase, mycelial growth was completely inhibited by these three compounds. Aromatic ITCs were less toxic in the petri dishes but were more toxic than aliphatic ITCs when dissolved in the agar. Benzyl ITC exhibited the highest inhibitory effect on sclerotial germination, with an EC₅₀ value of 75.1 µmol L^?1. Butyl and benzyl ITCs reduced apothecial production of S. sclerotiorum by 92.5% at the highest concentration. In in vivo assay, only allyl and 2‐phenylethyl ITCs reduced disease incidence (by 76.7 and 70% respectively) at low concentrations. CONCLUSION: Sclerotinia sclerotiorum in the soil might be suppressed by the higher concentrations of allyl and benzyl ITCs released from decomposition of Brassica juncea, B. carinata, B. nigra and Sinapis spp. Copyright © 2011 Society of Chemical Industry     

曲酸及氯曲酸衍生物的合成及抑菌活性

以曲酸为原料,设计合成了16个曲酸衍生物(QI-01~QI-16)和10个氯曲酸衍生物(QII-01~QII-10),通过核磁共振氢谱及元素分析对其结构进行了表征。初步抑菌活性测定结果表明:所有供试化合物对苹果炭疽病菌Glomerella cingulata和番茄灰霉病菌Botrytis cinerea的菌丝生长均有不同程度的抑制作用,其中化合物QI-07和QI-11对苹果炭疽病菌活性最高,50μg/mL时的抑制率分别为79.3%和86.2%;化合物QII-04、QII-08和QII-09对番茄灰霉病菌活性最高,50μg/mL时的抑制率分别为70.0%、70.0%和76.7%。     

Synthesis of D-glucosamine quaternary ammonium derivatives and evaluation of their antifungal activity together with aminodeoxyglucose derivatives against two wood fungi Coriolus versicolor and Poria placenta: structure-activity relationships

BACKGROUND: Structure–activity relationships are often reported in scientific studies. These may be employed in searching for new acceptable biocides to use against harmful microorganisms, because the biocides used hitherto encounter various problems, including lack of efficiency, high toxicity and persistence. Nowadays, scientists are trying to find new, environmentally acceptable biocides to replace these earlier biocides. Different compounds from renewable materials have been studied and have shown pronounced antifungal activity against wood fungi. These include aminopolysaccharide derivatives and different quaternary ammonium polymers. A biological study carried out with these products indicated a possible relationship between amino groups and differences in biological activity observed. RESULTS: In this study, an amino group was successively fixed to different carbon atoms of glucose, and glucosamine was also modified by both N‐alkylation and quaternisation. The impact of the amino group position on antifungal activity against two wood decay fungi was investigated. The amino group at the anomeric position showed the highest antifungal activity against both Coriolus versicolor Quel. and Poria placenta (Fr.) Cooke. Furthermore, the positive impact of both N‐alkylation and quaternisation on the growth of both strains was demonstrated. CONCLUSION: The anomeric position of the amino group and the N‐alkylation and quaternisation of amino sugars considerably increase the antifungal activity of these compounds. Copyright © 2010 Society of Chemical Industry     

Isolation and in vitro and in vivo activity against Phytophthora capsici and Colletotrichum orbiculare of phenazine-1-carboxylic acid from Pseudomonas aeruginosa strain GC-B26

The bacterial strain GC-B26, which showed strong antifungal and anti-oomycete activity against some plant pathogens, was isolated from a grassland soil in Korea. Based on morphological, physiological and biochemical characteristics, GC-B26 was identical to Pseudomonas aeruginosa (Schroeter) Migula. The antibiotic G26A, active against Phytophthora capsici Leonian and Colletotrichum orbiculare (Berk & Mont) van Arx, was isolated from the culture filtrates of Ps aeruginosa strain GC-B26 using various chromatographic procedures. The EI mass and UV spectral results indicated that G26A is an analogue of phenazines, having molecular formula C13H8N2O2 (M+, m/z 224.0664). On the basis of NMR spectral data, G26A was confirmed as phenazine-1-carboxylic acid. C orbiculare, P capsici and Pythium ultimum Trow were most sensitive to G26A, with MIC values of approximately 5 microg ml(-1). However, no antimicrobial activity was found against yeasts and bacteria, even at a concentration of over 100 microg ml(-1). Treatment with the antibiotic gave highly significant protective activity against the development of Phytophthora disease on pepper and anthracnose on cucumber plants. The disease control efficacy was only slightly less than that of the commercial fungicides metalaxyl and chlorothalonil.     

黄粉虫抗菌肽抑制植物病原真菌的适宜诱导处理

对饥饿后黄粉虫幼虫通过饲细菌、针刺饲真菌或放线菌法产生诱导免疫反应;研磨、冷冻离心法获得抗菌肽提取物.采用抑菌圈法测定其对24种植物病原真菌抑菌活性,统计分析抑菌活性处于前3名处理的频次.结果表明,初步得到了抑制植物病原真菌的黄粉虫抗菌肽适宜诱导处理.诱导处理方法对开发包括黄粉虫在内的昆虫抗菌肽是非常重要的.