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排序方式: 共有103条查询结果,搜索用时 2 毫秒
51.
目的研究云南省西双版纳采集的土样中黑黏座孢霉(Myrothecium roridumTode ex Fr.)发酵液的活性成分。方法通过硅胶柱色谱、制备薄层色谱、HPLC等手段进行分离纯化,并根据理化性质和光谱数据鉴定其化学结构。结果从黑黏座孢霉发酵液乙酸乙酯提取物中共分离得到2个化合物,经鉴定分别为黏液霉素A(verrucarin A)和黏液霉素J(verrucarin J),并利用稻瘟霉(Pyricu-laria oryzae)菌丝体形态变化作为活性指标,测定了它们的活性。结论黏液霉素A和J为首次从该菌种中分离得到。 相似文献
52.
Summary: The termination of storage life of most of the cereals is due to onset of attack by certain fungi. The grains may not be free from the infecting units and thus become a source to cause deleterious effects. Aspergillus flavus Link, Penicillium notatum Westling and Helminthosporium oryzae Breda de Haan isolated from the infected food stuff showed pronounced toxic effects on plants and animals. In the case of poultry, serious pathological changes are noted in the kidney, heart and liver when crude toxin preparations from Aspergillus flavus mixed with normal foodstuff was given. The toxins also inhibited germination of maize seeds and their growth. Attempts have been made during the course of the present study to isolate and identify the toxic compounds and determine their mode of action on plant and animal tissues.
Zusammenfassung: Die Lagerungsfähigkeit der meisten aus Getreide hergestellten Lebensmittel wird durch die schädliche Einwirkung bestimmter Pilze begrenzt. Getreide-körner können befallen sein und so die Ursache krankmachender Effekte werden. Aspergillus flavus Link, Penicillium notatum Westing und Helminthosporium oryzae Brede de Haan, die aus infizierten Nahrungsmitteln isoliert wurden, zeigten ausgepragte toxische Wirkung auf Pflanzen und Tiere. Bei Geflugel wurden nach Fütterung mit normalem Futter, dem ungereinigte Toxinextrakte aus Aspergillus flavus beigegeben waren, schwere pathologische Veranderungen an Niere, Herz und Leber beobachtet. Die Toxine hemmten auch die Auskeimung und das Wachstum von Maissamen. Im Rahmen dieser Untersuchung wurde der Versuch unternommen, die toxischen Verbindungen zu isolieren und zu identifizieren und ihre Wirkungsweise auf Pflanzen und Tiere zu bestimmen. 相似文献
Zusammenfassung: Die Lagerungsfähigkeit der meisten aus Getreide hergestellten Lebensmittel wird durch die schädliche Einwirkung bestimmter Pilze begrenzt. Getreide-körner können befallen sein und so die Ursache krankmachender Effekte werden. Aspergillus flavus Link, Penicillium notatum Westing und Helminthosporium oryzae Brede de Haan, die aus infizierten Nahrungsmitteln isoliert wurden, zeigten ausgepragte toxische Wirkung auf Pflanzen und Tiere. Bei Geflugel wurden nach Fütterung mit normalem Futter, dem ungereinigte Toxinextrakte aus Aspergillus flavus beigegeben waren, schwere pathologische Veranderungen an Niere, Herz und Leber beobachtet. Die Toxine hemmten auch die Auskeimung und das Wachstum von Maissamen. Im Rahmen dieser Untersuchung wurde der Versuch unternommen, die toxischen Verbindungen zu isolieren und zu identifizieren und ihre Wirkungsweise auf Pflanzen und Tiere zu bestimmen. 相似文献
53.
Significantly low level of small RNA accumulation derived from an encapsidated mycovirus with dsRNA genome 总被引:1,自引:0,他引:1
The role of RNA silencing as an antiviral defence has been well elucidated in plants and invertebrates, but not in filamentous fungi. We have previously determined the complete genome sequence of Magnaporthe oryzae virus 2 (MoV2), a dsRNA virus that infects the rice blast fungus Magnaporthe oryzae. In this study, we detected small interfering RNAs (siRNAs) from both positive- and negative-strand MoV2 viral RNA, suggesting that the RNA silencing machinery in M. oryzae functions against the mycovirus. Cloning and characterisation of MoV2 siRNAs indicated that, in MoV2, the ratio of virus-derived siRNAs to total small RNA is significantly lower than that in either plant viruses or Cryphonectria hypovirus 1 (CHV1), another mycovirus. Nevertheless, any MoV2-encoded proteins did not exhibit RNA silencing suppressor activity in both the plant and fungal systems. Our study suggests the existence of a novel viral strategy employed to evade host RNA silencing. 相似文献
54.
Rhizopus oryzae accumulates and degrades trehalose in response to environmental stress conditions such as heat, osmotic stress, nitrogen starvation and pH. When heat stress was applied to R. oryzae, the trehalose content of the cells was increased from 0.9 to 4.8 mg/g dw and when the stress was relieved it decreased back to 1.1 mg/g dw. Under osmotic stress and nitrogen starvation, trehalose content was increased by 3.5 and 3 fold, respectively. The decrease in external pH increased trehalose level up to 2.6 mg/g dw from 1.1 mg/g dw. Increased trehalose level decreased back to normal after pH stress was relieved. These results indicate that trehalose accumulates and acts as a stress protectant in R. oryzae. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
55.
Differential cDNA screening was used to identify genes expressed during the colonisation of rice leaves by the pathogenic
fungus Magnaporthe grisea. This led to the identification of a gene, called UEP1, which encodes a ubiquitin extension protein. UEP1 was highly expressed 48 h after initial fungal infection of rice leaves when M. grisea is proliferating in the leaf epidermis but not yet causing disease symptoms. UEP1 appeared to be down-regulated after this time despite further extensive growth of the fungus throughout the leaf tissue.
To investigate the potential role of ubiquitin in fungal pathogenesis we subsequently isolated UEP3 and PUB4, encoding a second ubiquitin extension protein and a polyubiquitin respectively. UEP1 was expressed abundantly during active growth of M. grisea in axenic culture but was down-regulated by starvation-stress. UEP3 showed a similar pattern of expression to UEP1 during the growth of M. grisea in culture and after environmental stress, but was not highly expressed during plant colonisation. PUB4 was highly expressed after environmental stress, but was not highly expressed during plant colonisation. UEP1 was found to be present in a much-higher copy number per haploid genome compared to UEP3 and PUB4. The restricted high-level expression of UEP1 suggests that M. grisea undergoes rapid ribosomal biogenesis and protein turnover during initial plant-tissue colonisation, which is regulated by
a specific UEP1-encoded component of the M. grisea ubiquitin gene family.
Received: 23 December 1997 / 17 March 1998 相似文献
56.
从13株米曲霉菌株中筛选到一株产氨基酰化酶活力较高的米曲霉(Aspergillus oryzae)W0607,以米曲霉w0607为生产菌固态发酵生产氨基酰化酶,较适的培养基组成和培养条件为;麸皮7.0g,豆饼粉3.0g,蛋白胨0.3g,水11mL,PH值6.5,发酵温度28℃,发酵周期约48h.在此条件下,米曲霉W0607的氨基酰化酶产率为400u/g左右. 相似文献
57.
目的从海洋真菌的代谢产物中寻找新的具有抗真菌活性的化合物。方法以稻瘟霉生物模型筛选海洋真菌,获得编号09-1-1-1的活性菌株,从其发酵液中分离活性代谢产物。结果从发酵液中分离到2个化合物,鉴定其结构为3a,12c-二氢-8-羟基-6-甲氧基-7H-呋喃[3′,2′∶4,5]呋喃[2,3-c]呫吨-7-酮(Ⅰ,sterig-matocystin)和1,3,6,8-四羟基-2-(1-羟己基)-9,10-蒽二酮(Ⅱ,averantin)。结论稻瘟霉生物模型用于筛选海洋真菌活性代谢产物成本低、快速又方便。化合物Ⅱ对109稻瘟霉菌丝的生长最小抑制浓度为1.6μg.mL-1。 相似文献
58.
Ping Shen San-Long Wang Xi-Kui Liu Chong-Ren Yang Bing Cai Xin-Sheng Yao 《Journal of Asian natural products research》2013,15(3):211-215
From the fresh rhizomes of Dioscorea deltoidea Wall var. orbiculata , a novel ergostanol saponin, orbiculatoside A ( 1 ), was isolated and identified as 3- O - g - d -glucopyranosyl-ergost-5-ene-3 g , 26-diol-26- O - g - d -glucopyranosyl(1 M 3)-[ g - d -glucopyranosyl(1 M 2)- g - d -glucupyranosyl(1 M 6)]- g - d -glucopyranoside by various NMR techniques in combination with chemical methods. The new saponin showed strong activity against Pyricularia oryzae , with a MMDC (minimum morphological deformation concentration) value of 28.04 w mol/l and was cytotoxic to cancer cell line K562, HCT-15, A549, HT1080, and A2780a in vitro . 相似文献
59.
Benedikt Stöcker Sonja Grundmann Pia Mosters Paul Nitzsche Randolf Brehler 《Archives of environmental & occupational health》2016,71(5):259-267
Aerogen lactase exposure carries a risk for the development of allergic asthma and rhinitis; only a few occupationally affected patients have been reported. The authors report the results of allergy testing with employees of a lactase tablets manufacturing plant. The survey involved 13 workers, including a questionnaire, spirometry, basophil activation test (BAT), and skin prick tests (SPTs) with lactase and a panel of common aeroallergens. Furthermore, lactase-specific immunoglobulin E (IgE) antibodies were analyzed. Sensitization to lactase could be proven for 9 workers by SPT and BAT; specific IgE antibodies could be detected in serum samples of all sensitized. However, IgE levels ≥0.35 kU/L were only found in 4 sera. These data confirm that occupational exposure to lactase can induce IgE-mediated respiratory sensitization resulting in allergic diseases. Protective measures should thus be obligatory when working with lactase. 相似文献
60.
一种新强心苷类化合物的结构鉴定及其活性研究 总被引:6,自引:0,他引:6
目的 从弯蕊开口箭(Tupistra wattii Hook.f.)中寻找抗癌活性先导化合物。方法 使用稻瘟霉活性筛选体系进行活性追踪分离,并通过波谱分析,特别是二维核磁手段结合化学方法对分离得到的化合物进行结构鉴定。结果 从弯蕊开口箭中分离得到3个具有很强细胞毒活性的强心苷,其中化合物2wattosideF是一个新化合物,并且它的细胞毒活性在3个强心苷中最强,其IC50值为0.011μmol/L。结论 wattoside F是一个具有很强细胞毒活性的新的强心苷类化合物。 相似文献