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1.
Two new anthraquinones have been isolated from the root bark of ventilago calyculata and their structures shown to be 2,4,8-trihydroxy-1-methoxy-3-methylanthraquinone and 2,4,8-trihydroxy-1,6-dimethoxy-3-methyl-anthraquinone.  相似文献   

2.
A new 3,4-dihydroxy-1-methoxy anthraquinone-2-corboxaldehyde (1) together with a known anthraquinone, damnacanthal (2), were isolated from the chloroform fraction of the aerial part (whole plant without root) of Saprosma fragrans. The isolated anthraquinones (1) and (2) were found to exhibit antifungal activity against Trichophyton mentagrophytes and Sporitrichum schenckii. Their structures were established by chemical and spectral analysis.  相似文献   

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Geosmithia fungi are little known symbionts of bark beetles. Secondary metabolites of lilac colored species G. lavendula and other nine Geosmithia species were investigated in order to elucidate their possible role in the interactions of the fungi with environment. Hydroxylated anthraquinones (yellow, orange, and red pigments), were found to be the most abundant compounds produced into the medium during the submerged cultivation. Three main compounds were identified as 1,3,6,8-tetrahydroxyanthraquinone (1), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone; 2), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (3). Compounds 2 and 3 (representing the majority of produced metabolites) inhibited the growth of G+-bacteria Staphylococcus aureus and Bacillus subtilis with minimum inhibitory concentration of 64–512 μg/mL. Anti-inflammatory activity detected as inhibition of cyclooxygenase-2 was found only for compound 3 at 1 and 10 μg/mL. Compound 2 interfered with the morphology, compound 3 with cell-cycle dynamics of adherent mammalian cell lines.  相似文献   

5.
Bioassay-directed fractionation of an antileukemic extract of Morinda parvifolia (Hong-Zhu-Teng) has led to the isolation and characterization of cytotoxic anthraquinones which include the new morindaparvin-B and the known lucidin-ω-methyl ether, lucidin-ω-methyl ether, digiferruginol, 1-hydroxy-6 or 7-hydroxymethylanthraquinone and 2-hydroxymethylanthraquinone in addition to the previously reported antileukemic morindaparvin-A and alizarin-1-methyl ether. 2-Hydroxymethylanthraquinone demonstrated significant activity (T/C = 150%) in the P-388 lymphocytic leukemia screen at 10 mg/kg/day. The structures of these compounds were determined by physicochemical data and spectral evidence.  相似文献   

6.
芦荟属植物叶内蒽醌类物质的组织化学定位研究   总被引:12,自引:1,他引:11  
蒽醌类物质是芦荟属(Aloe)植物叶内贮存的重要次生代谢物质,主要是芦荟素,高那特芦荟素,芦荟苦素和芦荟宁等。根据蒽醌类物质的理化性质,用2%-5%NaOH和5%Pb(CH3COO)2溶液对材料进行处理,再辅以荧光和超薄切片观察等多种方法,对芦荟叶内的4种主要蒽醌类物质进行了组织化学定位研究。结果表明,蒽醌类物质在芦荟叶内的贮藏是多位点的。芦荟素和高那特芦荟素主要位于韧皮部的大型薄壁组织细胞之中;而芦荟苦素和芦荟宁主要位于维管束鞘细胞以及贮水组织与同化薄壁组织之间的1圈薄壁组织细胞之中,贮水组织细胞中不贮存蒽醌类物质。  相似文献   

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Fungal pathogens     
《Current biology : CB》2020,30(19):R1163-R1169
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Ira F. Salkin 《CMAJ》1984,130(8):1068
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11.
Fungal glucoamylases   总被引:1,自引:0,他引:1  
Fungi are employed to produce industrially important glucoamylases. Most glucoamylases are glycosylated. Glycosylation enhances the enzyme stability. Glucoamylases contain both starch binding and catalytic binding domains, the former being responsible for activity on raw (insoluble) starch. Proteases may act on this domain causing the enzyme to lose its activity on insoluble starch. Optimal activity is observed at pH 4.5 to 6.5 and 50 to 70 degrees C. Glucoamylases contain up to 7 sub-sites with highly varying affinity. They can be produced by different methods including submerged, solid state and semi-solid state fermentation processes.  相似文献   

12.
《Current biology : CB》2021,31(24):R1557-R1563
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13.
Recent advances in medicine have caused fungal endocarditis (FE) to be a more common disease entity. A list of fungi is expanding as potential pathogens in FE, with Candida species and Aspergillus species being the most common. The combination of valvular heart disease along with indwelling devices and antibiotic use are the major predisposing factors for yeast endocarditis, whereas the presence of immunosuppression along with valvulopathy predisposes for mold endocarditis. The expanding population of immunosuppresed patients and individuals with intravascular devices has led to increased incidence of FE. Better outcome of FE depends on fast and accurate diagnosis and subsequent treatment. Echocardiography the most valuable recent technique allowed for early diagnosis of FE and is probably responsible for the improved prognosis of patients with FE. Nonculture-based diagnostic tests may further improve the sensitivity, specificity, and rapidity of microbiologic diagnosis of FE. The availability of the newer triazoles and echinocandins, providing broad spectrum antifungal activities with favorable safety profile may assist in achieving cure and further improving the prognosis of this disease entity.  相似文献   

14.
Fungi are used in many industrial processes, such as the production of enzymes, vitamins, polysaccharides, polyhydric alcohols, pigments, lipids, and glycolipids. Some of these products are produced commercially while others are potentially valuable in biotechnology. Fungal secondary metabolites are extremely important to our health and nutrition and have tremendous economic impact. In addition to the multiple reaction sequences of fermentations, fungi are extremely useful in carrying out biotransformation processes. These are becoming essential to the fine-chemical industry in the production of single-isomer intermediates. Recombinant DNA technology, which includes yeasts and other fungi as hosts, has markedly increased markets for microbial enzymes. Molecular manipulations have been added to mutational techniques as a means of increasing titers and yields of microbial processes and in the discovery of new drugs. Today, fungal biology is a major participant in global industry. Moreover, the best is yet to come as genomes of additional species are sequenced at some level (cDNA, complete genomes, expressed sequence tags) and gene and protein arrays become available.  相似文献   

15.
Successful penetration of living plant tissue by fungal pathogens is preceded by an exchange of signals between both organisms. Recent mutational approaches revealed the importance of cAMP-dependent signalling pathways for fungal development and virulence on their hosts.  相似文献   

16.
There are now four well-established methods to examine the chromosomes of filamentous fungi: mapping genes to linkage groups by recombination analyses, light-microscopic observation of chromosomes in meiotic divisions, electron-microscopic observation of the synaptonemal complexes between homologous chromosomes in prophase of meiosis, and separation of chromosomes as individual bands by pulsed field gel electrophoresis. These techniques and their contributions are described in brief with special reference toNeurospora. A fifth technique will be used more and more in characterizing chromosomes at the molecular level as DNA sequencing is completed for a limited number of the fungi. However, only the molecular studies of chromosome structures as they relate to centromeres, telomeres or nucleolus organizer regions are discussed, as is the potential usefulness of DNA sequencing to identify the junctions of chromosome rearrangements.  相似文献   

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The Botanical Review -  相似文献   

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Fungal endophthalmitis occurs secondary to trauma, as a complication of intraocular surgery, or as an extension of an adjacent or distant focus of fungal infection. In the United States, Candida species are the most common pathogens isolated, followed by Aspergillus species. Candida infections show a predilection towards vitreous involvement, whereas Aspergillus infections usually manifest as hemorrhagic infarcts of the retinal or choroidal vessels or as infiltration of the subretinal and subretinal pigment epithelial spaces. Endogenous Aspergillus endophthalmitis is associated with a high mortality rate, underscoring the severity of systemic infection. The prognosis of fungal endophthalmitis depends on the virulence of the organism, extent of intraocular involvement, and the timing and mode of interventions. Prompt therapy following early diagnosis helps to reduce significant visual loss. Despite the introduction of new-generation triazoles and echinocandins into clinical practice, successful therapy is limited by the delay in diagnosis and a lack of broad-spectrum antifungals with good intravitreal penetration that lack systemic toxicity.  相似文献   

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