Consulta: subjectFacets:"Biotransformation"
Registros recuperados: 28
Data/hora: 14/06/2024 16:00:42

Effects of aroma quality on the biotransformation of natural 2-phenylethanol produced using ascorbic acid
Provedor de dados: 69
Autores: Tian,Xun; Ye,Rui; Wang,Jingwen; Chen,Yifei; Cai,Baoguo; Guan,Shimin; Rong,Shaofeng; Li,Qianqian.
Background Natural 2-phenylethanol (2-PE) is an important flavoring that emits the aroma of roses. During biotransformation, the aroma quality of natural 2-PE is affected by its main by-products, which include butanol, isobutyric acid, butyric acid, and isovaleric acid. Thus, controlling undesirable by-product formation can reduce the effect of odor on 2-PE aroma quality. Results 2-PE was produced through biotransformation using l-phenylalanine as a substrate and glucose as a carbon source. Ascorbic acid was added to the system to improve the redox reaction and suppress the generation of by-products. Principal component analysis of the aroma quality of 2-PE was performed using an electronic nose. Similarity analysis revealed that the effects of four...
Tipo: Journal article
Palavras-chave: Aroma quality; Ascorbic acid; Biotransformation; By-products; 2-Phenylethanol.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000400005

Bioconversion of (+)- and (-)-alpha-pinene to (+)- and (-)-verbenone by plant cell cultures of Psychotria brachyceras and Rauvolfia sellowii
Provedor de dados: 69
Autores: Limberger,Renata Pereira; Aleixo,Adriana Mendes; Fett-Neto,Arthur Germano; Henriques,Amélia T.
This work describes the bioconversion of (-)- and (+)-alpha-pinene (2,6,6-trimethyl-bicyclo[3.1.1]hept-2-ene), targeted at the production of (-)- and (+)-verbenone (4,6,6-trimethyl-bicyclo (3.1.1) hept-3-en-2-one), respectively, using Psychotria brachyceras and Rauvolfia sellowii cell suspension cultures. P. brachyceras showed selectivity to (-)-alpha-pinene with 80.9% conversion (relative integrated area gas chromatography-mass spectrometry (GC-MS)) of (-)-verbenone in 10-day-incubation, whereas R. sellowii was able to convert both pinene enantiomers (37.6% conversion of (-)-verbenone in 7-day-incubation and 32.2% conversion of (+)-verbenone in 10-day-incubation). In both systems trans-verbenol was formed as main product and then slowly biocatalyzed to...
Tipo: Journal article
Palavras-chave: Alpha-pinene; Biotransformation; Verbenol; Verbenone.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000400003

Comparative embryotoxicity and genotoxicity of the herbicide diuron and its metabolites in early life stages of Crassostrea gigas: implication of reactive oxygen species production
Provedor de dados: 5
Autores: Behrens, Daphne; Rouxel, Julien; Burgeot, Thierry; Akcha, Farida.
Herbicides are one of the major classes of pollutants contaminating coastal waters over the world. Among them, diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a phenylurea herbicide frequently detected in oyster-producing area, known to be toxic for this important exploited non-target species. With the aim to investigate the mechanisms by which diuron displays its toxicity in oyster, the implication of both biotransformation and oxygen reactive species (ROS) production was studied considering embryotoxicity and genotoxicity as endpoints. Comparative embryotoxicity and genotoxicity of diuron and its main metabolites (DCPMU, DCPU and 3,4-DCA) were thus studied on oyster larvae by the embryo-larval bioassay on D larvae and the comet assay on trochophore...
Tipo: Text
Palavras-chave: Oyster; Herbicide; Embryotoxicity; Genotoxicity; Oxidative stress; Biotransformation.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00324/43521/43053.pdf

Effects of short-term exposure to paralytic shellfish toxins on clearance rates and toxin uptake in five species of New Zealand bivalve
Provedor de dados: 5
Autores: Contreras, Andrea; Marsden, Islay D.; Munro, Murray H. G.
Algal blooms produced by toxic dinoflagellates have increased worldwide, resulting in economic losses to aquaculture and fisheries. Bivalve species differ in their ability to feed on toxin-producing dinoflagellates and this could result in differences in toxin accumulation among species. In New Zealand, the effects of paralytic shellfish poisoning (PSP) toxins on the physiology of bivalve molluscs are relatively unknown. We hypothesised that the feeding responses of five New Zealand bivalve species exposed to PSP-toxic dinoflagellates would be species-specific, affecting their accumulation of toxins. Each species was exposed to toxic and non-toxic species of Alexandrium spp. and clearance rate used as an index of sensitivity to PSP toxins. Clearance rates...
Tipo: Text
Palavras-chave: Biotransformation; Decarbamoylation; Dosinia anus; Epimerisation; Ostrea chilensis; Paphies donacina; Pecten novaezelandiae; Perna canaliculus.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00069/18007/16007.pdf

Dietary exposure of juvenile common sole (Solea solea L.) to polybrominated diphenyl ethers (PBDEs): Part 2. Formation, bioaccumulation and elimination of hydroxylated metabolites
Provedor de dados: 5
Autores: Munschy, Catherine; Moisan, Karine; Tixier, Celine; Pacepavicius, G.; Alaee, M.
The uptake, elimination and transformation of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L) exposed to spiked contaminated food over a three-month period, and then depurated over a five-month period. Methoxylated (MeO-) and hydroxylated (OH-) PBDEs were determined in fish plasma exposed to PBDEs and compared to those obtained in control fish. While all MeO- and some OH- congeners identified in fish plasma were found to originate from non-metabolic sources, several OH- congeners, i.e., OH-tetraBDEs and OH-pentaBDEs, were found to originate from fish metabolism. Among these, 4 '-OH-BDE-49 was identified as a BDE-47 metabolite. Congener 4 '-OH-BDE-101, identified here for the first time, may be...
Tipo: Text
Palavras-chave: Marine flatfish; PBDEs; Bioaccumulation; Biotransformation; Hydroxylated metabolites.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00017/12811/11295.pdf

Dietary exposure of juvenile common sole (Solea solea L.) to polybrominated diphenyl ethers (PBDEs): Part 1. Bioaccumulation and elimination kinetics of individual congeners and their debrominated metabolites
Provedor de dados: 5
Autores: Munschy, Catherine; Moisan, Karine; Tixier, Celine; Olivier, Nathalie; Gastineau, Olivier; Le Bayon, Nicolas; Buchet, Vincent.
The uptake and elimination of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L) exposed to spiked contaminated food over a three-month period, then depurated over a five-month period. The results show that all of the studied PBDEs accumulate in fish tissues, including the higher brominated congener BDE-209. Several additional PBDE congeners were identified in the tissues of exposed fish, revealing PBDE transformation, mainly via debromination. The identified congeners originating from PBDE debromination include BDE-49 and BDE-202 and a series of unidentified tetra-, penta-, and hepta- BDEs. Contaminant assimilation efficiencies (AEs) were related to their hydrophobicity (log K-ow) and influenced by...
Tipo: Text
Palavras-chave: Marine flatfish; PBDEs; Bioaccumulation; Biotransformation; Debromination.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00021/13188/11296.pdf

Contamination des crustacés décapodes par les composes organohalogénés : étude détaille de la bioaccumulation des PCB chez l'araignée de mer Maja brachydactyla
Provedor de dados: 5
Autores: Bodin, Nathalie.
Marine decapod crustaceans are macrobenthic opportunist species, of great commercial interest, and can accumulate pollutants. Worrying about consumers' safety, polychlorobiphenyls (PCBs), polybromodiphenyl Ethers (PBDEs) and dioxins (PCDD/Fs) were analyzed in four crustacean species from the coastal waters of Brittany and Normandy. As regards to regulations, the consumption of crustacean muscle doesn't raise any health problems. The second objective of this study was to evaluate the biological processes influencing PCB bioaccumulation in the spider crab Maja brachydactyla. From a quantitative point of view, organotropism, diet and age were the major factors acting on contamination. From a qualitative point of view, PCB fingerprints depended on sex, and to...
Tipo: Text
Palavras-chave: Food safety; Biotransformation; Biomagnification; Food webs; Stable isotopes; Decapod crustaceans; Bioaccumulation; Polychlorinated biphenyls; Organic contaminants; Sécurité sanitaire; Biotransformation; Bioamplification; Réseaux trophiques; Isotopes stables; Crustacés décapodes; Bioaccumulation; Contaminants organiques.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-1149.pdf

Biochemical and genetic alterations in the freshwater neotropical fish Prochilodus lineatus after acute exposure to Microcystis aeruginosa
Provedor de dados: 83
Autores: Garcia,Cylene Zambrozi; Martinez,Claudia B. R.
Microcystins are secondary metabolites produced by different species of cyanobacteria, such as Microcystis aeruginosa (MA). In this study, the biochemical and genetic effects of lyophilized MA were evaluated in the neotropical fish Prochilodus lineatus exposed to 1 or 2 mg L-1 lyophilized MA (treated group) or only water (control group) in static toxicity tests for 24 and 96 h. The gills and liver were used in the analysis of biotransformation enzymes and antioxidant defenses, blood and gill cells in genetic analysis and in brain and muscle it was determined the activity of acetylcholinesterase (AChE). The results showed the biotransformation pathway activation due to the increase in hepatic CYP1A and in branchial and hepatic glutathione S-transferase...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acetylcholinesterase; Antioxidants; Biotransformation; Cyanotoxin; DNA damage.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000300015

Integrated biomarker response index using a Neotropical fish to assess the water quality in agricultural areas
Provedor de dados: 83
Autores: Vieira,Carlos Eduardo Delfino; Almeida,Mayara da Silva; Galindo,Bruno Ambrssio; Pereira,Lindalva; Martinez,Claudia Bueno dos Reis.
Aquatic ecosystems in areas with intense agricultural activity are subject to pesticide contamination, which may compromise the health of the fish. In order to verify the quality of the water and the possible effects of pesticides on fish, a method that combines different biomarker responses into an index named "integrated biomarker response" (IBR) was applied using the biological alterations in the Neotropical fish Astyanax altiparanae. Fish were maintained in situ at five sites along a stream that runs in an agricultural area and in a stream within a forest fragment, considered a reference site. After seven days of exposure the following alterations were observed in fish confined at experimental sites: increased activity of glutathione-S-transferase...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Astyanax altiparanae; Biomonitoring; Biotransformation; Genotoxicity; Pesticides.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000100153

Screening of whole yeast free-cells and optimization of pH and temperature for fructooligosaccharides production
Provedor de dados: 3
Autores: Deffert, Flávia; Agustini, Bruna Carla; Picheth, Geraldo; Bonfim, Tania Maria Bordin.
Fructooligosaccharides are catalyzed by β–fructofuranosidase enzyme, produced by many microorganisms. However, in order to achieve a more profitable, low time-consuming process with lower cost, researchers have sought alternatives. This study aimed to select and identify yeasts able to produce fructooligosaccharides and evaluate the influence of pH and temperature on their synthesis. Yeast suspensions, solutions of 500 g L-1 sucrose and three values of pH (4.5, 5.5, and 6.5) and temperature (40, 50, and 60ºC) were tested. Yeast species were identified by molecular techniques. Among 141 yeast isolates from grapes, 65 were able to synthesize fructooligosaccharides. The maximum concentration of fructooligosaccharides was 4.8% (w v-1), and Saccharomyces...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 2.12.00.00-9 prebiotics; Biotransformation; Identification; PCR. Microbiologia.
Ano: 2017
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/34140

A New Acetylcholinesterase Inhibitor from Green Glycosylation of Trachyloban-19-oic Acid by Mucor plumbeus
Provedor de dados: 42
Autores: SANTOS,GABRIEL F. DOS; TAKAHASHI,JACQUELINE A.
ABSTRACT The in vitro metabolism of a widespread natural product, trachyloban-19-oic acid (1), by the fungal species Mucor plumbeus was studied in a sucrose-yeast liquid medium. Two products were isolated, and their structures were determined by spectroscopic means as 7β-hydroxytrachyloban-19-oic acid (5) and trachyloban-19-O-β-D-glucopyranosyl ester (6). To the best of our knowledge, compound 6 is herein reported by the first time in the literature. These compounds were assayed for acetylcholinesterase inhibition along with some related compounds. Compound 6 showed the highest acetylcholinesterase inhibitory activity at 10000 µg/mL among the tested compounds, a result (92.89%) comparable to the activity of the positive control, galanthamine (94.21%)....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acetylcholinesterase inhibitors; Biotransformation; Green glycosylation; Mucor plumbeus; Trachyloban-19-oic acid.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000501961

Biotransformation of sucrose into 5-hydroxy-2-hydroxymethyl-γ-pirone by Aspergillus flavus
Provedor de dados: 42
Autores: Ferreira,Nelson R.; Sarquis,Maria Inez M.; Alves,Cláudio N.; Santos,Alberdan S.
The sucrose hydrolysis and the preference of consumption of glucose instead of fructose were investigated for the production of 5-hydroxy-2-hydroxymethyl-γ-pyrone (HHMP) in the presence of Aspergillus flavus IOC 3974 cultivated in liquid Czapeck medium. Standardized 0.5g of pellets were transferred as inoculum into twelve conical flasks of 250 ml containing 100 ml of medium with different sucrose concentration, which was kept at 120 rpm and 28"C for 16 days without pH adjustment. Aliquots of 500μl of the broth culture were withdrawn at 24 h intervals and analyzed. The major yield of HHMP was 26g l-1 in 120g l-1 of sucrose. At these conditions, A. flavus produced an invertase capable of hydrolyzing 65% of total sucrose concentration in 24h, and an isomerase...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aspergillus flavus; Biotransformation; Kojic acid; Secondary metabolite; Fructose-isomerase.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000300004

Isolation and screening of microorganisms with potential for biotransformation of terpenic substrates
Provedor de dados: 52
Autores: Bier,Mário César Jucoski; Poletto,Sabrina; Soccol,Vanete Thomaz; Soccol,Carlos Ricardo; Medeiros,Adriane Bianchi Pedroni.
The objective of the present work was to isolate and select strains with potential to perform the biotransformation of terpenic substrates. Microorganisms obtained from a collection culture and also isolated from a natural source of terpene substrate were tested. Seventeen strains were selected by their resistance to terpenes in potato dextrose agar containing up to 1% of limonene or α-pinene and β-pinene (1:1). Subsequently, 10 strains were selected by their capacity of using these terpenes as sole carbon source in a mineral medium. The biotransformation capacity of these strains was tested and the products obtained were identified by GC-MS.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aroma; Flavour; Limonene; Β-pinene; Biotransformation.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000500020

Citotoxicity of Fipronil on Hepatocytes Isolated from Rat and Effects of Its Biotransformation
Provedor de dados: 52
Autores: Guelfi,Marieli; Maioli,Marcos Antonio; Tavares,Marco Aurélio; Mingatto,Fábio Erminio.
ABSTRACT The aim of this study was to characterize the mechanism of toxicity of fipronil on hepatocytes isolated from the rat and the effect of its biotransformation on the toxicological potential. The toxicity of fipronil was assessed by monitoring the oxygen consumption and mitochondrial membrane potential, intracellular ATP concentration, Ca2+ homeostasis and cell viability. The cell viability was evaluated by trypan blue exclusion in hepatocytes that were isolated from the normal rats and by the release of the enzymes alanine transaminase and aspartate transaminase in hepatocytes that were isolated from the normal rats or proadifen-pretreated rats. Fipronil reduced mitochondrial respiration in the cells that were energized with glutamate plus malate in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fipronil; Hepatotoxicity; Bioenergetics; Biotransformation; Calcium homeostasis.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132015000600843

Biotransformation of Benzaldehyde to L-Phenylacetylcarbinol (L-PAC) by Free Cells of Torulaspora delbrueckii in presence of Beta-Cyclodextrin
Provedor de dados: 52
Autores: Shukla,Vilas. B.; Kulkarni,Pushpa R.
Studies were carried out to explore the possibility of decreasing the toxic and inhibitory effects of the substrate benzaldehyde during its biotransformation to L-PAC by free cells of Torulaspora delbrueckii using beta -cyclodextrin (beta -CD). Use of various levels of benzaldehyde and acetaldehyde in presence of 2% of beta -CD showed that, in presence of beta -CD, the organism could tolerate higher levels of benzaldehyde and acetaldehyde. Semi-continuous feeding of benzaldehyde and acetaldehyde was found to increase the yield of L-PAC in comparison with one time feeding.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Benzaldehyde; Biotransformation; Cyclodextrin; L-phenylacetycarbinol; Torulaspora delbrueckii.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132002000300003

Biotransformation of the monoterpene, limonene, by Fusarium verticilloides
Provedor de dados: 52
Autores: Oliveira,Brás Heleno de; Strapasson,Rogério Antônio.
Limonene, the main constituent of the orange peel oil, was used as substrate for the biotransformation by the fungus Fusarium verticilloides. A hydroxylated derivative of limonene was isolated from the culture broth and characterized by spectroscopic methods. It was identified as perillyl alcohol, an important anti-cancer compound.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Limonene; Perillyl alcohol; Biotransformation; Fusarium verticilloides.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000100002

Production of allyl phenyl carbinol (APC) by biotrans-formation using Rhizopus arrhizus
Provedor de dados: 52
Autores: Shukla,Vilas B.; Kulkarni,Pushpa R.
The objective of the present work was to study the stereoselective synthesis of homo-allylic alcohol using stereoselective hydrolysis by Rhizopus arrhizus and also to study the stereoselective synthesis of allyl phenyl carbinol (APC) or 1-Phenyl-3-butene-1-o by combination of chemical synthesis and biotransformation from cheap raw materials such as benzaldehyde and allyl bromide. Stereospecific synthesis of allyl phenyl carbinol (APC) was achieved by acetate hydrolysis by R. arrhizus giving R (+) enantiomer. Maximum enantiomeric excess of APC was obtained at 16 h where as maximum yield of it was obtained at 48 h of biotransformation.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Allyl Phenyl Carbinol; Biotransformation; Rhizopus arrhizus.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000300001

Enzymatic systems involved in D-limonene biooxidation
Provedor de dados: 52
Autores: Menéndez,Pilar; García,Carlos; Rodríguez,Paula; Moyna,Patrick; Heinzen,Horacio.
The biooxidation of limonene by an Aspergillus strain resulted in the production of perillyl alcohol and short chain fatty acids. Addition of ketoconazole, a known inhibitor of cytochrome P450 oxydase, eliminated the production of free acids, but did not affect biotransformation to perillyl alcohol.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Limonene; Biotransformation; Perillyl alcohol; Cytochrome oxydase; Inhibitors.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132002000200001

Effects of pregnancy and protein-energy malnutrition on monooxygenase O-dealkylation activity in rat liver microsomes
Provedor de dados: 56
Autores: Kuriyama,S.N.; De-Oliveira,A.C.A.X.; Fidalgo-Neto,A.A.; Paumgartten,F.J.R.
Xenobiotic metabolism is influenced by a variety of physiological and environmental factors including pregnancy and nutritional status of the individual. Pregnancy has generally been reported to cause a depression of hepatic monooxygenase activities. Low-protein diets and protein-energy malnutrition have also been associated with a reduced activity of monooxygenases in nonpregnant animals. We investigated the combined effects of pregnancy and protein-energy malnutrition on liver monooxygenase O-dealkylation activity. On pregnancy day 0 rats were assigned at random to a group fed ad libitum (well-nourished, WN) or to a malnourished group (MN) which received half of the WN food intake (12 g/day). WN and MN rats were killed on days 0 (nonpregnant), 11 or 20...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Cytochrome P450; Monooxygenases; Xenobiotic metabolism; Undernutrition; Gestation; Biotransformation.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000100014

Whole cells in enantioselective reduction of benzyl acetoacetate
Provedor de dados: 58
Autores: Ribeiro,Joyce Benzaquem; Ramos,Aline de Souza; Lopes,Raquel de Oliveira; Silva,Gabriela Veloso Vieira da; Souza,Rodrigo Octavio Mendonça Alves de.
The β-ketoester benzyl acetoacetate was enantioselectively reduced to benzyl (S)-3-hydroxybutanoate by seven microorganism species. The best result using free cells was obtained with the yeast Hansenula sp., which furnished 97% ee and 85% of conversion within 24 h. After immobilization in calcium alginate spheres, K.marxianus showed to be more stable after 2 cycles of reaction.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biotransformation; Chiral reduction; Β-ketoester; Kluyveromyces marxianus; Immobilization.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000300023

Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2
Provedor de dados: 58
Autores: Khanolkar,Dnyanada S.; Naik,Milind Mohan; Dubey,Santosh Kumar.
A bacterial isolate capable of utilizing tributyltin chloride (TBTCl) as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME) analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM). Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: TBTCl; Morphological alteration; Biotransformation; DBTCl2; Bioremediation.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400014

Biotransformation of a cage-like diels-alder adduct and derivatives by Mucor ramosissimus samutsevitsch
Provedor de dados: 58
Autores: Ito,Felicia Megumi; Mena,Ana Elisa Maciel; Marques,Maria Rita; Lima,Dênis Pires de; Beatriz,Adilson.
The present study aimed to evaluate the ability for biotransformation of the Diels-Alder adduct tricyclo[6.2.1.0(2,7)]undeca-4,9-dien-3,6-dione (1) and two synthetic derivatives by the saprobe fungus Mucor ramosissimus Samutsevitsch. Products from oxidation, isomerization and, regioselective and enantioselective reduction were achieved.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mucor ramosissimus; Biotransformation; Diels-Alder adduct.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000300019

Optimization of diterpenes bioconversion process by the fungus Cephalosporium aphidicola
Provedor de dados: 58
Autores: Takahashi,Jacqueline Aparecida; Barroso,Henrique de Almeida; Oliveira,Alaíde Braga de.
Parameters for a more efficient biotransformation of diterpene-like compounds by the fungus Cephalosporium aphidicola were established by carrying out microscale feedings at several conditions. Experiments were guided by thin layer chromatography and gas chromatography analysis. It was observed that the substrate should be added in ethanol at concentrations between 15 to 30 mg per 100 ml of medium. The extraction of the product showed to be more efficient when carried out from both mycelia and broth and using ethylacetate as the extracting solvent. The experiment should be stopped six days after feeding the substrate to the fungus for the best product yield.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cephalosporium aphidicola; Biotransformation; Diterpene.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822000000200003

Selection of filamentous fungi of the Beauveria genus able to metabolize quercetin like mammalian cells
Provedor de dados: 58
Autores: Costa,Eula Maria de M. B.; Pimenta,Fabiana Cristina; Luz,Wolf Christian; Oliveira,Valéria de.
Microbial biotransformations constitute an important alternative as models for drug metabolism study in mammalians and have been used for the industrial synthesis of chemicals with pharmaceutical purposes. Several microorganisms with unique biotransformation ability have been found by intensive screening and put in commercial applications. Ten isolates of Beauveria sp genus filamentous fungi, isolated from soil in the central Brazil, and Beauveria bassiana ATCC 7159 were evaluated for their capability of quercetin biotransformation. Biotransformation processes were carried out for 24 up to 96 hours and monitored by mass spectrometry analyses of the culture broth. All strains were able to metabolize quercetin, forming mammalian metabolites. The results were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Beauveria bassiana; Biotransformation; Quercetin.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000200036

Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites
Provedor de dados: 58
Autores: Mercimek,Hatice Aysun; Dincer,Sadik; Guzeldag,Gulcihan; Ozsavli,Aysenur; Matyar,Fatih; Arkut,Afet; Kayis,Fikret; Ozdenefe,Melis Sumengen.
Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitroexperiments. Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L−1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL−1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pseudomonas sp; Biotransformation; Nitroaromatic explosives; TNT.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000100103

Biotransformation of poly (epsilon-caprolactone) and poly (vinyl chloride) blend
Provedor de dados: 58
Autores: Campos,Adriana de; Franchetti,Sandra Mara Martins; Agnelli,José Augusto Marcondes.
Poly (caprolactone) is a famous biodegradable polymer and miscible with PVC, a commercial synthetic polymer, thermal susceptible and non-biodegradable. This blend is important concerning its mechanical properties and biodegradability. In this work, we testified the biomodification of blend films of PVC/PCL by UV-Vis. spectroscopy. The results show us that there is an interaction between the PVC/PCL film and the microrganisms.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biotreatment; UV-Vis; PVC/PCL blend; Biotransformation.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000500038

Twenty-six years of HIV science: an overview of anti-HIV drugs metabolism
Provedor de dados: 60
Autores: Andrade,Carolina Horta; Freitas,Lenis Medeiros de; Oliveira,Valéria de.
From the identification of HIV as the agent causing AIDS, to the development of effective antiretroviral drugs, the scientific achievements in HIV research over the past twenty-six years have been formidable. Currently, there are twenty-five anti-HIV compounds which have been formally approved for clinical use in the treatment of AIDS. These compounds fall into six categories: nucleoside reverse transcriptase inhibitors (NRTIs), nucleotide reverse transcriptase inhibitors (NtRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), cell entry inhibitors or fusion inhibitors (FIs), co-receptor inhibitors (CRIs), and integrase inhibitors (INIs). Metabolism by the host organism is one of the most important determinants of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: AIDS/treatment; Drugs/anti-HIV; Drugs/metabolism; Antiretroviral drugs; Biotransformation.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502011000200003

Microbial biotransformation of beclomethasone dipropionate by Aspergillus niger
Provedor de dados: 60
Autores: Ahmad,Saeed; Khaliq,Farhan Hameed; Madni,Asadullah; Shahid,Muhammad Nabeel; Pervaiz,Irfan.
In the present research, the steroidal anti-asthmatic drug beclomethasone dipropionate was subjected to microbial biotransformation by Aspergillus niger. Beclomethasone dipropionate was transformed into various metabolites first time from microbial transformation. New drug metabolites produced can act as new potential drug molecules and can replace the old drugs in terms of safety, efficacy, and least resistance. They were purified by preparative thin layer chromatography technique, and their structures were elucidated using modern spectroscopic techniques, such as 13C NMR, 1H NMR, HMQC, HMQC, COSY, and NOESY, and mass spectrometry, such as EI-MS. Four metabolites were purified: (i) beclomethasone 17-monopropionate, (ii) beclomethasone 21-monopropionate,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anti-asthmatics; Aspergillus niger/use in biotransformation; Beclomethasone dipropionate/microbial biotransformation; Steroids/microbial transformation; Biotransformation.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502014000400903