micellar catalysis Dotaz Zobrazit nápovědu
Micellar enzymology, a new trend in molecular biology, studies catalysis by enzymes entrapped in hydrated reversed micelles of surfactants (phospholipids, detergents) in organic solvents. In this review, the key research problems of micellar enzymology are formulated and examples of biocatalysis in microheterogeneous media are discussed. In particular, new applications are presented of micellar enzymology in fine organic syntheses, in clinical and chemical analyses (bioluminescence and enzyme immunoassays), in bioconversion of energy and mass, in therapy (engineering of new drugs capable of targeted penetration into cells), as well as in biotechnology (processes using nanogranulated or nanocapsulated enzymes).
Micellar enzymology, a new trend in molecular biology, studies catalysis by enzymes entrapped in hydrated reversed micelles composed of surfactants (phospholipids, detergents) in organic solvents. The key research problems of micellar enzymology and its relation to enzyme membranology are discussed.
- MeSH
- enzymy fyziologie MeSH
- kinetika MeSH
- makromolekulární látky MeSH
- membrány enzymologie MeSH
- micely MeSH
- rozpustnost MeSH
- substrátová specifita MeSH
- techniky in vitro MeSH
- termodynamika MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- enzymy MeSH
- makromolekulární látky MeSH
- micely MeSH
- voda MeSH
Benzoxonium chloride belongs to the group of quaternary ammonium salts, which have been widely used for decades as disinfectants because of their high efficacy, low toxicity, and thermal stability. In this study, we have prepared the C10-C18 set of benzoxonium-like salts to evaluate the effect of their chemical and biological decontamination capabilities. In particular, biocidal activity against a panel of bacterial strains including Staphylococcus aureus in biofilm form was screened. In addition, the most promising compounds were successfully tested against Francisella tularensis as a representative of potential biological warfare agents. From a point of view of chemical warfare protection, the efficiency of BOC-like compounds to degrade the organophosphate simulant fenitrothion was examined. Notwithstanding that no single compound with universal effectiveness was identified, a mixture of only two compounds from this group would be able to satisfactorily cover the proposed decontamination spectrum. In addition, the compounds were evaluated for their cytotoxicity as a basic safety parameter for potential use in practice. In summary, the dual effect on chemical and biological agents of benzoxonium-like salts offer attractive potential as active components of decontamination mixtures in the case of a terrorist threat or chemical or biological accidents.
- Klíčová slova
- benzoxonium, decontamination, disinfection, micellar catalysis, organophosphates, quaternary ammonium salts,
- Publikační typ
- časopisecké články MeSH
The oxidation of catechol in neutral and slightly alkaline aqueous solutions (pH 7-9.6) by excess hydrogen peroxide (0.002-0.09 mol/L) in the presence of Co(II) (2.10(-7)-2.10(-5) mol/L) is accompanied by abrupt formation of red purple colouration, which is subsequently decolourized within 1 h. The electron spectra of the reaction mixture are characterized by a broad band covering the whole visible range (400-700 nm), with maximum at 485 nm. The reaction is initiated by catechol oxidation to its semiquinone radical and further to 1,2-benzoquinone. By nucleophilic addition of hydrogen peroxide into the p-position of benzoquinone C=O groups, hydroperoxide intermediates are formed, which decompose to hydroxylated 1,4-benzoquinones. It was confirmed by MS spectroscopy that monohydroxy-, dihydroxy- and tetrahydroxy-1,4-benzoquinone are formed as intermediate products. As final products of catechol decomposition, muconic acid, its hydroxy- and dihydroxy-derivatives and crotonic acid were identified. In the micellar environment of hexadecyltrimethylammonium bromide the decomposition rate of catechol is three times faster, due to micellar catalysis, and is accompanied by chemiluminescence (CL) emission, with maxima at 500 and 640 nm and a quantum yield of 1 x 10(-4). The CL of catechol can be further sensitized by a factor of 8 (maximum) with the aid of intramicellar energy transfer to fluorescein.
- MeSH
- časové faktory MeSH
- cetrimoniové sloučeniny chemie MeSH
- cetrimonium MeSH
- hmotnostní spektrometrie metody MeSH
- ionty chemie MeSH
- katecholy chemická syntéza chemie MeSH
- kobalt chemie MeSH
- koncentrace vodíkových iontů MeSH
- luminiscenční měření přístrojové vybavení metody MeSH
- micely MeSH
- oxidace-redukce MeSH
- peroxid vodíku chemie MeSH
- roztoky chemie MeSH
- senzitivita a specificita MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- catechol MeSH Prohlížeč
- cetrimoniové sloučeniny MeSH
- cetrimonium MeSH
- ionty MeSH
- katecholy MeSH
- kobalt MeSH
- micely MeSH
- peroxid vodíku MeSH
- roztoky MeSH
- voda MeSH
