The present invention relates to variants of a parent laccase. The present invention also relates to polynucleotides encoding the variant laccases and to nucleic acid constructs, vectors, and host cells comprising the polynucleotides, and methods of using the variant enzymes.
-
(2011/05/03)
Facile procedure for the synthesis of N-aryl-N-hydroxy carbamates
An efficient one-pot procedure for the zinc-mediated reduction of nitroarenes in the presence of chloroformates leading to the corresponding N,O-bisprotected hydroxylamine is described. Reactions proceed smoothly under ambient conditions in THF-water mixt
Porzelle, Achim,Woodrow, Michael D.,Tomkinson, Nicholas C. O.
experimental part
p. 798 - 802
(2009/07/25)
Kinetics and mechanism of base-catalysed degradations of substituted aryl-N-hydroxycarbamates, their N-methyl and N-phenyl analogues
The kinetics and mechanism of the degradation reactions of substituted phenyl N-hydroxycarbamates and their N-methyl and N-phenyl analogues have been studied at pseudo-first-order reaction conditions in aqueous buffers and sodium hydroxide solutions at 20°C and 60°C and at I = 1 mol·1 -1. The dependence of log kobs on pH for phenyl N-hydroxycarbamates at pH 13 is linear with the unit slope; at pH 10-12 log kobs is pH independent. The Bronsted coefficient βlg is about -1 (pH 7-13) and -1.53 (pH > 13) indicating that the degradation reaction of phenyl N-hydroxycarbamates follows an ElcB mechanism giving the corresponding phenol/phenolate and HO-N=C=O. The latter species undergoes further decomposition to give carbonate, nitrogen and ammonia as final products. In contrast to the phenyl N-hydroxycarbamates the N-methyl derivatives at pH 7-9 undergo degradation to the corresponding phenol/phenolate, carbonate and methylamine via a concerted mechanism (βlg is about - 0.75). The only exception is 4-nitrophenyl N-hydroxy-N-methylcarbamate in which the predominant break down pathway proceeds via the Smiles rearrangement to give sodium N-methyl-(4-nitrophenoxy)carbamate. At pH > 9 the reaction of N-hydroxy-N-methylcarbamates is kinetically complex: the dependence of absorbance on time is not exponential and it proceeds as a consecutive two-step reaction. N-Hydroxy-N-phenylcarbamate under the same conditions undergoes degradation to phenol, carbonate, aniline and azoxybenzene.
ANTIMICROBIAL COMPOSITION COMPRISING AN OXIDOREDUCTASE AND AN ENHANCING AGENT OF THE N-HYDROXYANILIDE-TYPE
-
-
(2008/06/13)
ANTIMICROBIAL COMPOSITION CONTAINING AN OXIDOREDUCTASE AND AN ENHANCER OF THER N-HYDROXYANILIDE-TYPE
The present invention relates to an enzymatic composition capable of killing or inhibiting microbial cells or micro-organisms, e.g. in laundry, on hard surfaces, in water systems, on skin, on teeth or on mucous membranes. The present invention also relate
-
(2008/06/13)
More Articles about upstream products of 4645-72-1