The Experts below are selected from a list of 1398 Experts worldwide ranked by ideXlab platform
N. M. Mandel - One of the best experts on this subject based on the ideXlab platform.
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Paecilomyces variotii central nervous system infection in a patient with cancer.
Mycoses, 2003Co-Authors: A. S. Kantarcıoğlu, G. Hatemi, G.s. De Hoog, Ayhan Yücel, N. M. MandelAbstract:Paecilomyces variotii was isolated from two subsequent cerebrospinal fluid (CSF) specimens of a cancer patient. Identification was confirmed through beta-tubulin and rDNA ITS sequencing. MICs were determined for seven antifungal agents; the isolate was found to be susceptible to amphotericin B (AMB), itraconazole (ITZ), ketaconazole (KTZ) and 5-fluorocytosine (5FC) but resistant to fluconazole (FLZ) and miconazole (MCZ). Despite antimycotic therapy, the infection proved to be fatal.
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Paecilomyces variotii central nervous system infection in a patient with cancer Fallbericht. ZNS-Infektion durch Paecilomyces variotii bei einem Krebspatienten
2003Co-Authors: G. Hatemi, G.s. De Hoog, N. M. MandelAbstract:Summary Paecilomyces variotii was isolated from two subsequent cerebrospinal fluid (CSF) specimens of a cancer patient. Identification was confirmed through b-tubulin and rDNA ITS sequencing. MICs were determined for seven antifungal agents; the isolate was found to be susceptible to amphotericin B (AMB), itraconazole (ITZ), ketaconazole (KTZ) and 5-fluorocytosine (5FC) but resistant to fluconazole (FLZ) and miconazole (MCZ). Despite antimycotic therapy, the infection proved to be fatal. Zusammenfassung Paecilomyces variotii wurde zweimal aus Liquorproben einer Krebspatientin isoliert. Die
Gabriela Alves Macedo - One of the best experts on this subject based on the ideXlab platform.
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detoxification of castor bean residues and the simultaneous production of tannase and phytase by solid state fermentation using Paecilomyces variotii
Bioresource Technology, 2011Co-Authors: Jose Valdo Madeira, Juliana Alves Macedo, Gabriela Alves MacedoAbstract:In this work, we introduce a biological detoxification method that converts toxic waste from castor beans into animal feed material. This method simultaneously induces the production of tannase and phytase by Paecilomyces variotii; both enzymes have high levels of activity and have the potential to be used in feedstuffs because they decrease overall anti-nutritional factors. The maximum tannase and phytase activities obtained were 2600 and 260 U/g after 48 and 72 h, respectively. SDS-PAGE electrophoresis of the fermented castor cake extracts revealed a reduction in ricin bands during fermentation, and the bands were no longer visible after 48 h. The cytotoxicity of the extracts was evaluated by MTT testing on RAW cells, and a progressive increase in cellular viability was obtained, reaching almost 100% after 72 h of fermentation.
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Immobilization of Paecilomyces variotii tannase and properties of the immobilized enzyme.
Journal of microencapsulation, 2011Co-Authors: Patrícia Fernanda Schons, Vania Battestin, Fernanda Cristina Rezende Lopes, Gabriela Alves MacedoAbstract:Tannase produced by Paecilomyces variotii was encapsulated in sodium alginate beads and used for the effective hydrolysis of tannic acid; the efficiency of hydrolysis was comparable to that of the free enzyme. The alginate beads retained 100% of their efficiency in the first three rounds of successive use and 60% in rounds 4 and 5. The response surface methodology showed that the best conditions to hydrolysis of tannic acid by immobilized tannase were: sodium alginate 5.2%, CaCl2 0.55 M and 9 h to curing time. The optimized process resulted in 2.4 times more hydrolysed tannic acid than that obtained before optimization. The optimum pH for the actions of both the encapsulated and the free enzymes was 5.5. The optimum temperature of the reaction was determined to be 40°C for the free enzyme and 60°C for the immobilized form. The immobilization process improved the stability at low pH.
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Hydrolysis of epigallocatechin gallate using a tannase from Paecilomyces variotii
Food Chemistry, 2008Co-Authors: Vania Battestin, Gabriela Alves Macedo, V.p. De FreitasAbstract:Epigallocatechin (EGC) and gallic acid (GA) were prepared by the degalloylation of an epigallocatechin gallate (EGCG) extract from green tea. EGCG was entirely hydrolyzed using a tannase (from Paecilomyces variotii) at pH 6.0, incubating at 40 °C for 30 min. The antiradical properties and the reducing power of these samples were assessed using the DPPH and FRAP assays, respectively. This work established a relationship between the antioxidant effects of epigallocatechin gallate and the enzymatic reaction products (epigalocatechin and gallic acid). The enzymatic reaction products showed higher scavenging activity and antioxidant capacity when compared to epigallocatechin gallate.
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Purification and Biochemical Characterization of Tannase from a Newly Isolated Strain of Paecilomyces variotii
Food Biotechnology, 2007Co-Authors: Vania Battestin, Gabriela Alves MacedoAbstract:An extracellular tannase was isolated from Paecilomyces variotii and partially purified using ammonium sulphate precipitation followed by DEAE-Sepharose ion exchange chromatography. Paecilomyces variotii is a newly isolated strain obtained in Sao Paulo, Brazil, from the screening of 500 fungi evaluated for their production of tannase. The tannase was separated into two peaks. SDS-PAGE analysis indicated that the purified enzyme migrated as a single protein band corresponding to molecular mass of 87.3 kDa (major peak) and 71.5 kDa (minor peak). The peaks eluted very close together between 150 and 250 mM NaCl. DEAE-Sepharose column chromatography led to an overall purification of 19.3 fold. The Km was found to be 0.61 μmol and the Vmax = 0.55 U.mL−1. Temperatures from 40 to 65°C and pH values from 4.5 to 6.5 were optimum for tannase activity and stability. This tannase could find potential use in the food-processing industry.
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tannase production by Paecilomyces variotii
Bioresource Technology, 2007Co-Authors: Vania Battestin, Gabriela Alves MacedoAbstract:: Surface response methodology was applied to the optimization of the laboratory scale production of tannase using a lineage of Paecilomyces variotii. A preliminary study was conducted to evaluate the effects of variables, including temperature ( degrees C), residue (%) (coffee husk:wheat bran), tannic acid (%) and salt solutions (%) on the production of tannase during 3, 5 and 7 days of fermentation. Among these variables, temperature, residues and tannic acid had significant effects on tannase production. The variables were optimized using surface response methodology. The best conditions for tannase production were: temperature (29-34 degrees C); tannic acid (8.5-14%); % residue (coffee husk:wheat bran 50:50) and incubation time of 5 days. The supplementation of external nitrogen and carbon sources at 0.4%, 0.8% and 1.2% concentration on tannase production were studied in the optimized medium. Three different nitrogen sources included yeast extract, ammonia nitrate and sodium nitrate along with carbon source (starch) were studied. Only ammonia nitrate showed a significant effect on tannase production. After the optimization process, the tannase activity increased 8.6-fold.
Bin-gui Wang - One of the best experts on this subject based on the ideXlab platform.
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Oxepine-Containing Diketopiperazine Alkaloids from the Algal-Derived Endophytic Fungus Paecilomyces variotii EN-291
Helvetica Chimica Acta, 2015Co-Authors: Peng Zhang, Jia-ning Wang, Xiao-ming Li, Bin-gui WangAbstract:Two new oxepine-containing diketopiperazine-type alkaloids, varioloids A and B (1 and 2, resp.), were isolated from the algal-derived fungus Paecilomyces variotii EN-291. The structures and absolute configurations were determined by detailed interpretation of 1D- and 2D-NMR spectroscopic data and by analysis of acidic hydrolysates. Compounds 1 and 2 exhibited potent activity against the plant-pathogenic fungus Fusarium graminearum with MIC values of 8 and 4 mu g/ml, respectively.
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Oxepine‐Containing Diketopiperazine Alkaloids from the Algal‐Derived Endophytic Fungus Paecilomyces variotii EN‐291
Helvetica Chimica Acta, 2015Co-Authors: Peng Zhang, Jia-ning Wang, Bin-gui WangAbstract:Two new oxepine-containing diketopiperazine-type alkaloids, varioloids A and B (1 and 2, resp.), were isolated from the algal-derived fungus Paecilomyces variotii EN-291. The structures and absolute configurations were determined by detailed interpretation of 1D- and 2D-NMR spectroscopic data and by analysis of acidic hydrolysates. Compounds 1 and 2 exhibited potent activity against the plant-pathogenic fungus Fusarium graminearum with MIC values of 8 and 4 mu g/ml, respectively.
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Varioxepine A, a 3H‐Oxepine‐Containing Alkaloid with a New Oxa‐Cage from the Marine Algal‐Derived Endophytic Fungus Paecilomyces variotii.
ChemInform, 2015Co-Authors: Peng Zhang, Jia-ning Wang, Tibor Kurtán, Attila Mándi, Bin-gui WangAbstract:The alkaloid varioexpine A (I) is isolated from the marine fungus Paecilomyces variotii and its structure is characterized by NMR spectroscopy and X-ray analysis.
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prenylated indole alkaloids from the marine derived fungus Paecilomyces variotii
Chinese Chemical Letters, 2015Co-Authors: Peng Zhang, Jia-ning Wang, Bin-gui WangAbstract:Two new prenylated indole alkaloids, namely, dihydrocarneamide A (1) and iso-notoamide B (2), were isolated from the marine-derived endophytic fungus Paecilomyces variotii EN-291. The structures of these metabolites were determined based on comprehensive spectral analysis, together with chiral HPLC analysis of the acidic hydrolysates. Unlike other prenylated indole alkaloids such as asperparalines, notoamides, and versicolamides, compounds 1 and 2 are the rare examples of C-5 prenylation, forming the fused dimethyldihydropyran ring at C-5 and C-6 of the indole ring. The cytotoxic activity of the isolated compounds was evaluated. (C) 2014 Bin-Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. All rights reserved.
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varioxepine a a 3h oxepine containing alkaloid with a new oxa cage from the marine algal derived endophytic fungus Paecilomyces variotii
ChemInform, 2015Co-Authors: Peng Zhang, Jia-ning Wang, Tibor Kurtán, Attila Mándi, Bin-gui WangAbstract:The alkaloid varioexpine A (I) is isolated from the marine fungus Paecilomyces variotii and its structure is characterized by NMR spectroscopy and X-ray analysis.
Angela M. Huang - One of the best experts on this subject based on the ideXlab platform.
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Treatment of Paecilomyces variotii pneumonia with posaconazole: case report and literature review.
Mycoses, 2016Co-Authors: Ryan Feldman, Leslie R. Cockerham, Blake W. Buchan, Angela M. HuangAbstract:The fungi Paecilomyces variotii is a potential pathogen in immunocompromised and immunocompetent patients. Their rare association with clinical disease results in scarce literature regarding susceptibility and treatment. Here, we discuss a case involving successful treatment of probable P. variotii pneumonia with posaconazole after treatment failure with voriconazole. The current literature related to antifungal susceptibility profiles, microbiological identification methods and clinical management of infections caused by this organism is also reviewed.
Dimitrios P. Kontoyiannis - One of the best experts on this subject based on the ideXlab platform.
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Voriconazole-resistant disseminated Paecilomyces variotii infection in a neutropenic patient with leukaemia on voriconazole prophylaxis
The Journal of infection, 2005Co-Authors: Georgios Chamilos, Dimitrios P. KontoyiannisAbstract:Paecilomyces variotii, an emerging hyalohyphomycetes, has been reported to be susceptible in vitro to voriconazole. We describe a case of disseminated P. variotii infection in a neutropenic child with relapsed leukaemia who was on voriconazole prophylaxis. The P. variotii isolate was resistant to voriconazole in vitro. The patient responded to liposomal amphotericin B.
