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).     

昆虫病原线虫共生菌YL001细胞内代谢产物 抑菌作用研究初报

以生物活性跟踪法测定了菌株代号为YL001的昆虫病原线虫共生菌Xenorhabdus nematophilus细胞内代谢产物的不同溶剂提取物及其不同馏分的抑菌活性。结果表明,YL001细胞内代谢产物的乙醇提取物和甲醇提取物的抑菌活性均高于石油醚提取物、乙酸乙酯提取物和正丁醇提取物,前两种提取物对番茄灰霉病菌Botrytis cinerea和辣椒疫霉病菌Phytophthora capsici的72 h菌丝生长抑制作用最强,在0.4 mol/mL浓度时抑制率均达100％。乙醇提取物经硅胶柱层析分离,洗出液合并后收集得到8个馏分。测定了各馏分对番茄灰霉病菌菌丝生长的抑制作用,结果表明:馏分F6的抑菌活性最高,在0.5 mol/mL浓度时,96 h的菌丝生长抑制率可达96.09%;提取物的活性段主要集中在馏分F6、F7和F8。活体组织法测定结果表明,其乙醇提取物在10 mg/mL的剂量下对番茄灰霉病的保护效果为64.81%,治疗效果为62.03%。     

枯草芽胞杆菌NCD-2菌株抑菌蛋白的分离及鉴定

枯草芽胞杆菌NCD-2菌株对灰葡萄孢菌具有较强的抑菌活性,抑菌蛋白是其产生的抑菌物质之一。本研究为明确NCD-2菌株所产抑菌蛋白的作用方式和特性,采用牛津杯法测定抑菌蛋白的抑菌活性及其对病原菌菌丝生长的影响,采用混合培养法测定其对病原菌分生孢子萌发的影响,同时采用阴离子交换层析和非变性聚丙烯酰胺凝胶电泳技术对其进行分离纯化,并利用MALDI-TOF-MS进行鉴定。结果表明,NCD-2菌株产生的粗蛋白能够显著抑制灰葡萄孢菌分生孢子的萌发和菌丝生长,并导致病原菌菌丝分枝增多、局部膨大肿胀。通过分离纯化获得具抑菌活性的蛋白组分D1-3,经鉴定该蛋白的肽指纹图谱与leucyl aminopeptidase[Bacillus subtilis](WP_041057629.1)的氨基酸序列匹配率最高,达到65%,相对分子质量为53.936 k Da,功能分析表明组分D1-3可能是一种新的抑菌蛋白。     

来源于植物的短肽LD-1对番茄灰霉病的抑制作用及其抗病性研究

短肽LD-1是从牛心朴子草根中新分离的具有抗菌活性的多肽。本文以番茄灰霉病为供试菌株,研究了短肽LD-1对番茄灰霉病的抑制作用及其抗病性。结果表明:短肽LD-1对番茄灰霉病菌菌丝生长及孢子萌发具有较好的抑制作用。离体试验中,短肽LD-1对番茄灰霉病菌菌丝生长抑制作用的EC50在24、48、72h分别为28.3051、30.2134、32.7427mg/L,对孢子萌发的EC50为16.6919mg/L;活体试验中,短肽LD-1对番茄灰霉病具有较好的防治效果,90mg/L短肽LD-1对番茄灰霉病防治效果达到74.24%。短肽LD-1能导致病菌芽管发育畸形,不能正常发育。短肽LD-1对番茄种子的萌发和根系生长具有明显的促进效果,并且经短肽LD-1处理后的番茄须根发达,须根数目明显增多,促进了番茄的生长发育,提高了抗病性。     

硬毛棘豆根的抑菌活性成分研究

为明确硬毛棘豆Oxytropis hirta Bunge根的农用抑菌活性成分,用75％乙醇浸提硬毛棘豆根,得到粗提物;再分别以石油醚、乙酸乙酯与正丁醇为溶剂对粗提物进行萃取,得到不同溶剂萃取相;通过活性追踪法对抑菌活性好的乙酸乙酯相运用现代柱层析与波谱学技术进行了分离与结构鉴定,并对所分离的化合物进行了抑菌活性评价.结...     

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。     

5种植物精油抑菌活性及其化学成分研究

从植物精油中寻找新型抑菌剂是植物化学研究的一个方向。本试验提取了丁香、八角、孜然、薄荷和生姜5种药食兼用植物的精油,采用抑制菌丝生长法和96孔板法测试了5种精油对8种植物病原真菌和5种细菌的抑菌活性。结果表明5种植物精油对测试真菌有不同程度的抑制作用,丁香的抑制作用最强,对梨黑星病菌的抑制作用最强,其IC_(50)为93.44 mg/L;5种植物精油对测试细菌的抑菌作用较弱,孜然和生姜精油对青枯菌的抑制最强,最小抑菌浓度(MIC)也仅为125 mg/L。采用气相色谱-质谱联用仪(GC-MS)分析了各精油的主要化学成分,八角主要成分为茴香脑(53.16%),薄荷主要成分为长叶薄荷酮(15.85%),丁香主要成分为丁子香酚(82.68%),生姜主要成分为香叶醛(16.80%),孜然主要成分为茴香甲醛(46.06%)。本研究结果表明丁香具有开发为新型植物源抑菌剂的潜力。     

7种植物精油对番茄灰霉病的抑制效果

以番茄灰霉病菌为供试对象,系统测试了香茅油、柠檬草油、樟油、黄樟油、天然冬青油、山苍子油、肉桂油等7种植物精油的抑菌效果。结果表明:7种精油中,樟油和肉桂油对番茄灰霉病的抑制效果较好。离体活性测试中,樟油和肉桂油对番茄灰霉病菌菌丝生长抑制作用的EC50分别为126.6205mg/L和128.1587mg/L,对孢子萌发的EC₅₀分别为181.8763mg/L和228.5453mg/L;活体组织法测试表明,2种精油对番茄灰霉病具有较好的保护效果,在500mg/L浓度下,黄瓜子叶法防效均达100%,果实针刺法防效分别为52.42%和50.48%;盆栽试验表明两者在2000mg/L时,对番茄灰霉病的防效分别为59.65%和61.40%。     

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.     

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%。     

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.     

拮抗链霉菌B28 的分类鉴定及其生防作用研究

 An antagonistic Streptomyces strain B28, isolated from the soil collected in Tianmu mountain of Zhejiang Province, was identified as Streptomyces diastatochromogenes by morphological , physiological & biochemical characteristics and 16S rDNA sequence alignment. Antagonistic study indicated that its secondary metabolite toyocamycin had an antifungal activity on the mycelial growth of seven species of plant pathogenic fungi. The results showed that toyocamycin possessed marked inhibitory activity against Rhizoctonia solani and the EC50 value was 0. 58 μg / mL. The effective of toyocamycin against Botrytis cinerea and Fusarium oxysporum f. sp. cucumerinum was much higher than that against Colletotrichum gloeosporioides, the EC50 value of
toyocamycin in inhibiting B. cinerea, F. oxysporum and C. gloeosporioides were 13. 65 μg / mL, 12. 33 μg / mL, and 30. 15 μg / mL respectively.     

齐墩果酸肟醚类化合物的合成及杀菌活性

为了开发潜在的氨基葡萄糖-6-磷酸合成酶（GlmS）抑制剂和杀菌剂,设计并合成了30个齐墩果酸肟醚类化合物,其中29个为新化合物,其结构均经1H NMR、13C NMR和高分辨质谱确证。采用Elson-Morgan法和菌丝生长速率法,分别测定了目标化合物对GlmS的抑制活性和杀菌活性。结果表明:在0.35 mmol/L下,大部分目标化合物对GlmS表现出一定的抑制活性,其中,化合物A-01、A-02、A-04、C-04和C-05对GlmS的抑制率在30%左右;部分化合物在50 μg/mL下对油菜菌核病菌Sclerotinia sclerotiorum（Lib.）de Bary、番茄灰霉病菌Botrytis cinerea Pers. 和稻瘟病菌Pyricularia oryzae Cav. 具有较好的杀菌活性,其中,化合物A-01、A-02、A-04、A-05和B-02对油菜菌核病菌的抑制率在88%左右,具有进一步研究的价值。     

Biological evaluation of neopeptins isolated from a Streptomyces strain

BACKGROUND: Microbial secondary metabolites are a rich source of antifungal agents and have merit as alternatives to synthetic fungicides. To develop disease control agents against powdery mildew, the lipopeptide antibiotic neopeptins were identified from the culture broth of a Streptomyces sp., and in vivo control efficacy of the compounds was evaluated on cucumber plants under glasshouse conditions. RESULTS: The Streptomyces sp. KNF2047 antagonistic against powdery mildew development in cucumber plants was isolated from a soil sample. Antifungal compounds were purified from the culture broth and identified as neopeptin A and B. In vitro microtitre assays revealed the inhibitory activities of the compounds in the range 128-512 microg mL(-1) against the mycelial growth of Alternaria mali, Botrytis cinerea, Cladosporium cucumerinum, Colletotrichum lagenarium, Didimella bryoniae and Magnaporthe grisea. Although neither compound showed remarkable in vitro antifungal activity against other plant pathogenic fungi, a mixture of neopeptins (484 mg of neopeptin A and 290 mg of neopeptin B per gram of partially purified powder) showed potent protective and curative activity against cucumber powdery mildew in vivo. The disease control activity of the neopeptins at a concentration of 2.4 mg L(-1) was 92.1%, which was similar to that of the commercial fungicide fenarimol (89.3% at 63 mg L(-1)) and that of the commercial biocontrol agent Actinovate (67.4% at 2 x 10(7) cfu L(-1)). CONCLUSION: Neopeptin mixtures isolated from Streptomyces sp. KNF2047 showed potent disease control activity against powdery mildew development on cucumber plants. .     

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。     

肉桂精油对4种重要果蔬病原真菌的生物活性研究

为进一步明确肉桂精油的农用抑菌活性,采用菌丝生长速率法、孢子萌发法和活体组织法系统测试了其对番茄灰霉病菌、苹果青霉病菌、番茄茎枯病菌和黄瓜镰刀菌4种重要果蔬病原真菌的抑菌活性。结果表明,肉桂精油对番茄灰霉病菌的抑制效果较好。离体活性测试中,肉桂精油对4种供试菌菌丝生长的抑制中浓度（EC50）分别为272.17、324.78、316.24、326.95 mg/L;对4种供试菌孢子萌发的EC50分别为196.01、273.52、390.44、311.23 mg/L。果实针刺法试验结果表明,在10 g/L处理剂量下,肉桂精油对番茄灰霉病的治疗作用和保护作用分别为64.16%和34.90%（3 d）,保护作用与对照药剂1 g/L腐霉利无显著差异。     

黄瓜炭疽病菌代谢物中抑菌活性成分研究

采用大孔吸附树脂提取和硅胶柱层析分离技术,从黄瓜炭疽病菌Colletotrichum orbiculare代谢物中获得一个抗真菌化合物,采用高分辨质谱、核磁共振波谱和红外光谱等技术鉴定了其化学结构,并评价了其对番茄灰霉病菌、西瓜枯萎病菌、烟草赤星病菌、苹果炭疽病菌和玉米弯孢病菌的孢子萌发和菌丝生长的抑制作用。结果表明:该化合物为间二羟基苯甲酸大环内酯类抗生素——根赤壳菌素;其对所有供试真菌的孢子萌发均未表现出明显的抑制活性,但对番茄灰霉病菌Botrytis cinerea的菌丝生长表现出很强的抑制作用。     

拟康宁木霉T-51菌株发酵液对灰葡萄孢的抑菌活性

拟康宁木霉菌株T-51是从土壤中分离得到的一株优秀生防菌株,在前期的研究与应用中表现出对番茄灰霉病的良好防效。本文研究了T-51菌株的PDB发酵液对灰葡萄孢的抑菌活性,结果表明T-51发酵液在0.5%的低浓度下的抑菌率达到52.1%,与高浓度(10%)发酵液的抑菌率(59.7%)没有显著差异。当发酵液浓度下降为0.05%时失去抑菌活性。T-51摇培至第5天时的发酵液的抑菌活性稳定。T-51发酵液中的抑菌物质对高温不敏感,沸水浴处理10 min后抑菌活性没有明显降低。T-51发酵液pH为3.3,呈酸性,当调节pH至7时,发酵液抑菌活性从57.89%下降到46.61%。T-51发酵液能够显著抑制灰葡萄孢侵染番茄叶片后产生的病斑大小,接种后叶片病斑直径比对照减小53.9%。     

冬青卫矛内生放线菌Streptomyces flavofuscus G1 发酵液中抑菌活性成分研究

从冬青卫矛内生放线菌Streptomyces flavofuscus G1的发酵液中分离得到化合物G13和G19。经核磁共振波谱及质谱分析,并结合相关文献,两个化合物分别被鉴定为phencomycin(G13)和4'-deacetyl-(-)-griseusin A(G19)。抑菌活性测定结果表明:G19对水稻白叶枯病菌Xanthomonas oryzae pv.oryzae、铜绿假单孢菌Pseudomonas aeruginosa(1.203 1)、蜡状芽孢杆菌Bacillus cereus(1.184 6)及金黄色葡萄球菌Staphyloccocus aureus(1.008 9)等供试病原细菌具有强烈的抑制作用,其最低抑菌浓度(MIC)值均为1.56μg/m L;对苹果树腐烂病菌Valsa mali和小麦赤霉病菌Fusarium graminearum菌丝生长亦有明显的抑制作用,其IC50值分别为14.70和24.35μg/m L。而G13对植物病原真菌油菜菌核病菌Sclerotinia sclerotiorum和苹果树腐烂病菌V.mali菌丝生长有强烈的抑制作用,其IC50值分别为5.21和4.82μg/m L。     

含单萜酚结构酰胺类杂合分子的设计与合成及抑菌活性

为寻找具有良好抑菌活性的酰胺类化合物,本研究将天然单萜酚类化合物香芹酚和百里香酚与琥珀酸脱氢酶抑制剂(SDHI)药效团拼合,设计并合成了30个酰胺类杂合分子,其结构经核磁共振氢谱(1H NMR)、碳谱(13C NMR)及高分辨质谱(HRMS)等确认。采用菌丝生长速率法测定了目标化合物对5种植物病原真菌的抑菌活性。结果表明,目标化合物对茄链格孢菌Alternaria solani和灰葡萄孢Botrytis cinerea的抑菌活性较好,其中 7e (N-(4-羟基-5-异丙基-2-甲基苯)-3-甲基噻吩-2-酰胺)的活性最高,对茄链格孢菌和灰葡萄孢的EC₅₀值分别为3.28和15.06 μg/mL,且 7e 与啶酰菌胺之间没有交互抗性。琥珀酸脱氢酶(SDH)活性测定表明, 7e 对灰葡萄孢敏感、抗性和B-P225F突变菌株的SDH均具有较强的抑制活性。分子对接研究表明, 7e 与野生型和突变型灰葡萄孢琥珀酸脱氢酶(BcSDH)之间具有较强的亲和力;推测 7e 是潜在的新型SDHI,其与啶酰菌胺之间对菌株SDH抑制活性的差异和与野生型和突变型BcSDH之间结合模式的差异,可能是二者之间没有交互抗性的原因。