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351.
用DPPH自由基清除法、羟基自由基清除法、铁离子鳌合能力和还原能力等方法对4种野生珍稀食用菌美味牛肝菌、羊肚菌、松茸和印度块菌的粗多糖进行了抗氧化活性评价。结果显示,4种真菌粗多糖均不同程度地具有抗氧化活性。印度块菌对DPPH自由基的清除活性和铁离子螯合能力最高,其EC50值分别为0.86 mg.mL-1和0.63 mg.mL-1;羊肚菌对羟基自由基的清除活性最高,其EC50值为0.38 mg.mL-1;美味牛肝菌的还原力最高,其EC50值为0.85 mg.mL-1;松茸清除DPPH及羟基自由基的能力最低,铁离子螯合能力也较低。 相似文献
352.
孜然提取物对几种病菌生物活性的初步研究 总被引:22,自引:0,他引:22
以孜然种子丙酮提取物为材料,测定了其对几种病菌的生物活性。结果表明,在供试质量浓度为0.05g/mL时,粗提物对所有供试真菌菌丝生长抑制率均大于75%;在供试质量浓度为0.1g/mL时,对稻瘟病菌孢子萌发抑制率大于90%;在供试质量浓度为0.04g/mL时,盆栽试验显示其对白菜黑斑病、稻瘟病及黄瓜霜霉病的保护作用均达60%以上,对稻瘟病治疗作用达89.5%以上。孜然作为植物源杀菌剂值得进一步研究。 相似文献
353.
Sulfated polysaccharides and their lower molecular weight oligosaccharide derivatives from marine macroalgae have been shown to possess a variety of biological activities. The present paper will review the recent progress in research on the structural chemistry and the bioactivities of these marine algal biomaterials. In particular, it will provide an update on the structural chemistry of the major sulfated polysaccharides synthesized by seaweeds including the galactans (e.g., agarans and carrageenans), ulvans, and fucans. It will then review the recent findings on the anticoagulant/antithrombotic, antiviral, immuno-inflammatory, antilipidemic and antioxidant activities of sulfated polysaccharides and their potential for therapeutic application. 相似文献
354.
In the search for bioactive natural products, our lab screens hydrophobic extracts from marine fungal strains. While hydrophilic active substances were recently identified from marine macro-organisms, there was a lack of reported metabolites in the marine fungi area. As such, we decided to develop a general procedure for screening of hydrophobic metabolites. The aim of this study was to compare different processes of fermentation and extraction, using six representative marine fungal strains, in order to define the optimized method for production. The parameters studied were (a) which polar solvent to select, (b) which fermentation method to choose between solid and liquid cultures, (c) which raw material, the mycelium or its medium, to extract and (d) which extraction process to apply. The biochemical analysis and biological evaluations of obtained extracts led to the conclusion that the culture of marine fungi by agar surface fermentation followed by the separate extraction of the mycelium and its medium by a cryo-crushing and an enzymatic digestion with agarase, respectively, was the best procedure when screening for hydrophilic bioactive metabolites. During this development, several bioactivities were detected, confirming the potential of hydrophilic crude extracts in the search for bioactive natural products. 相似文献
355.
Camila Spereta Bertanha Ana Helena Januário Tavane Aparecida Alvarenga Letícia Pereira Pimenta Márcio Luis Andrade e Silva Wilson Roberto Cunha Patrícia Mendon?a Pauletti 《Marine drugs》2014,12(6):3608-3633
Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinones. A compilation of the 13C-NMR spectral data of these compounds is also presented. 相似文献
356.
植物源农药印楝素微胶囊化工艺及防虫效果 总被引:2,自引:0,他引:2
该试验采用界面聚合法,对植物源农药印楝素进行微胶囊化,并通过正交试验优化微胶囊制备的工艺条件,旨在提高印楝素的稳定性,延长其田间防虫持效期.结果表明:壁材采用3∶4(m∶m)的甲苯-2,4-二异氰酸酯(TDD与六亚甲基四胺,芯材与壁材的配比为30∶7(m∶m),溶剂采用3∶2(m∶m)的乙酸乙酯和二甲苯混合溶剂比效适宜,微胶囊中印楝素的包埋率为(83.16±1.22)%.所制得的印楝素微胶囊剂通过盆栽试验表明,对昆虫具有较好的防治效果和较长的持效期. 相似文献
357.
358.
359.
为寻找高活性的新农药化合物,以3-取代氨基-1-芳基丙酮-1-肟与氨基甲酸酯反应,设计并合成了19个氨基甲酸苯丙酮肟酯衍生物,其结构均经核磁共振氢谱和元素分析确证。初步的生物活性测定结果表明,化合物具有一定的生物活性,其中 c11 在浓度为500 mg/L时,对蚜虫Aphis craccivora的致死率达到90%以上; c16和c17 在1 000 mg/L时,对朱砂叶螨Tetranychus cinabarinus 的致死率达到100%。 相似文献
360.
Similar to other marine holobionts, fish are colonized by complex microbial communities that promote their health and growth. Fish-associated microbiota is emerging as a promising source of bioactive metabolites. Pleuronectes platessa (European plaice, plaice), a flatfish with commercial importance, is common in the Baltic Sea. Here we used a culture-dependent survey followed by molecular identification to identify microbiota associated with the gills and the gastrointestinal tract (GIT) of P. platessa, then profiled their antimicrobial activity and metabolome. Altogether, 66 strains (59 bacteria and 7 fungi) were isolated, with Proteobacteria being the most abundant phylum. Gill-associated microbiota accounted for higher number of isolates and was dominated by the Proteobacteria (family Moraxellaceae) and Actinobacteria (family Nocardiaceae), whereas Gram-negative bacterial families Vibrionaceae and Shewanellaceae represented the largest group associated with the GIT. The EtOAc extracts of the solid and liquid media cultures of 21 bacteria and 2 fungi representing the diversity of cultivable plaice-associated microbiota was profiled for their antimicrobial activity against three fish pathogens, human bacterial pathogen panel (ESKAPE) and two human fungal pathogens. More than half of all tested microorganisms, particularly those originating from the GIT epithelium, exhibited antagonistic effect against fish pathogens (Lactococcus garvieae, Vibrio ichthyoenteri) and/or human pathogens (Enterococcus faecium, methicillin-resistant Staphylococcus aureus). Proteobacteria represented the most active isolates. Notably, the solid media extracts displayed higher activity against fish pathogens, while liquid culture extracts were more active against human pathogens. Untargeted metabolomics approach using feature-based molecular networking showed the high chemical diversity of the liquid extracts that contained undescribed clusters. This study highlights plaice-associated microbiota as a potential source of antimicrobials for the control of human and the aquaculture-associated infections. This is the first study reporting diversity, bioactivity and chemical profile of culture-dependent microbiota of plaice. 相似文献