• MeSH
• endotoxiny analýza   MeSH
• lipopolysacharidy MeSH
• Listeria patogenita   MeSH
• peptidy MeSH

• Klíčová slova
• fenol,

• NLK Obory
• environmentální vědy
• chemie, klinická chemie
• NLK Publikační typ
• publikace WHO

• MeSH
• fenoly MeSH
• ionty MeSH
• kovy MeSH
• měď MeSH
• Poliovirus MeSH
• RNA virová MeSH

• MeSH
• fenoly normy   MeSH
• vystavení vlivu životního prostředí MeSH

• Konspekt
• Veřejné zdraví a hygiena
• NLK Obory
• environmentální vědy
• NLK Publikační typ
• publikace WHO

• MeSH
• aminopyrin analýza   MeSH
• fenoly MeSH
• spektrofotometrie MeSH
• tablety MeSH

OBJECTIVE: Comamonas testosteroni Pb50 is a microorganism that possesses high tolerance for phenol and shows strong phenol degrading activity. This bacterial strain is capable of utilizing phenol as the sole carbon and energy source. Although examples are known in which the C. testosteroni utilizes phenol for growth or metabolism, much less information are known on the nature of the phenol-oxidizing enzymes in this microorganism. Therefore, the occurrence and cellular location of phenol hydroxylase (EC 1.14.13.7), the enzyme participating in the first step of phenol degradation, catalyzing its hydroxylation to catechol in a bacterial Comamonas testosteroni Pb50 strain grown in the presence of phenol as a sole carbon and energy source are the aims of this study. METHODS: Combination of fractionation with polyethylene glycol 6000 and gel permeation chromatography on columns of Sepharose 4B and Sephacryl S-300 was used for isolation of phenol hydroxylase detectable in the medium in which C. testosteroni was cultivated. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel chromatography on Sephacryl S-300 were used to evaluate the molecular mass of the enzyme. The enzyme activity was followed by HPLC (phenol consumption and/or catechol formation). RESULTS: Whereas low activity of phenol hydroxylase was detected in cytosol isolated from C. testosteroni, more than 16-fold higher activity of this enzyme was found in the medium in which C. testosteroni was cultivated. The presence of phenol hydroxylase extracellular activity suggests that this microorganism may secrete the enzyme into the extracellular medium. Using the procedure consisting of fractionation with polyethylene glycol 6000 and gel permeation chromatography on columns of Sepharose 4B and Sephacryl S-300, the enzyme was isolated from the medium to homogeneity. The formation of catechol mediated by purified phenol hydroxylase is strictly dependent on the presence of NADPH, which indicates that this enzyme is the NADPH-dependent phenol hydroxylase. The enzyme is a homotetramer having a molecular mass of 240 000, consisting of four subunits having a molecular mass of 60 000. The optimum pH of the enzyme for the phenol oxidation is pH 7.6. CONCLUSION: The results are the first report showing isolation and partial characterization of extracellular NADPH-dependent phenol hydroxylase of a bacterial C. testosteroni Pb50 strain capable of oxidizing phenol to catechol. The data demonstrate the progress in resolving the enzymes responsible for the first step of phenol degradation by bacteria.

• MeSH
• časové faktory MeSH
• Comamonas testosteroni enzymologie   genetika   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• extracelulární prostor enzymologie   genetika   MeSH
• fenol metabolismus   MeSH
• katalýza MeSH
• katecholy metabolismus   MeSH
• klonování DNA MeSH
• koncentrace vodíkových iontů MeSH
• NADP metabolismus   MeSH
• oxidace-redukce MeSH
• oxygenasy se smíšenou funkcí genetika   izolace a purifikace   metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• DNA izolace a purifikace   MeSH
• leukocyty MeSH

• MeSH
• chromatografie MeSH
• fenol škodlivé účinky   toxicita   MeSH
• formaldehyd analogy a deriváty   škodlivé účinky   toxicita   MeSH
• fototoxická dermatitida MeSH
• morčata MeSH
• rostlinné exsudáty škodlivé účinky   toxicita   MeSH
• Check Tag
• morčata MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• dermatovenerologie

Flavonoids are associated with positive cardiovascular effects. However, due to their low bioavailability, metabolites are likely responsible for these properties. Recently, one of these metabolites, 4-methylcatechol, was described to be a very potent antiplatelet compound. This study aimed to compare its activity with its 22 close derivatives both of natural or synthetic origin in order to elucidate a potential structure-antiplatelet activity relationship. Blood from human volunteers was induced to aggregate by arachidonic acid (AA), collagen or thrombin, and plasma coagulation was also studied. Potential toxicity was tested on human erythrocytes as well as on a cancer cell line. Our results indicated that 17 out of the 22 compounds were very active at a concentration of 40 μM and, importantly, seven of them had an IC50 on AA-triggered aggregation below 3 μM. The effects of the most active compounds were confirmed on collagen-triggered aggregation too. None of the tested compounds was toxic toward erythrocytes at 50 μM and four compounds partly inhibited proliferation of breast cancer cell line at 100 μM but not at 10 μM. Additionally, none of the compounds had a significant effect on blood coagulation or thrombin-triggered aggregation. This study hence reports four phenol derivatives (4-ethylcatechol, 4-fluorocatechol, 2-methoxy-4-ethylphenol and 3-methylcatechol) suitable for future in vivo testing.

• MeSH
• agregace trombocytů * MeSH
• fenol * MeSH
• fenoly farmakologie   MeSH
• inhibitory agregace trombocytů farmakologie   MeSH
• lidé MeSH
• thrombin farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• bolest farmakoterapie   MeSH
• fenoly terapeutické užití   MeSH
• nádory močového měchýře farmakoterapie   MeSH
• Publikační typ
• kazuistiky MeSH