Chemistry: molecular biology and microbiology – Micro-organism – tissue cell culture or enzyme using process... – Preparing compound containing saccharide radical
Reexamination Certificate
2000-12-01
2002-12-31
Prats, Francisco (Department: 1651)
Chemistry: molecular biology and microbiology
Micro-organism, tissue cell culture or enzyme using process...
Preparing compound containing saccharide radical
C435S105000, C435S100000, C435S137000, C435S158000
Reexamination Certificate
active
06500649
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a new process for the conversion of organic materials, particularly saccharide materials, comprising an oxidation step carried out under particular conditions, namely combining, at least at a given moment, a means of enzymatic oxidation capable of generating hydrogen peroxide and at least one particular metal, namely ruthenium and/or palladium.
The invention also relates to a process as described above comprising an additional step involving the oxidation or reduction of the material oxidised enzymatically beforehand.
In particular, the claimed process makes it possible to obtain, in a simple, rapid and inexpensive manner, organic materials, particularly those of a saccharide nature, oxidised with high selectivity then optionally reduced or re-oxidised, having numerous industrial applications, including the use as synthesis intermediates, such as glucosone, galactosone, gluconic, 2-keto-gluconic or isoascorbic acids, fructose, sorbitol, mannitol etc.
The term “organic materials” within the meaning of the present invention means both saccharide materials and non-saccharide organic materials.
The latter include alcohols and organic acids of a non-saccharide nature such as, for example, lower alcohols including methanol, fatty alcohols, glycerol, cholesterol, polyvinyl alcohols, hydroxycarboxylic acids including malic acid, the respective derivatives thereof and, generally, all organic products other than saccharides which are potentially capable of being oxidised enzymatically with the concomitant production of hydrogen peroxide.
As mentioned, the process forming the subject matter of the invention may be applied advantageously to saccharide materials, this idea being in no way limiting and including linear, cyclic or branched monosaccharides, disaccharides, trisaccharides, oligosaccharides and mixtures of these products such as hydrolysates of starch, insulin or cellulose.
It may also be applied to saccharide materials which have undergone, before the characteristic step of enzymatic oxidation, at least one step involving chemical, enzymatic and/or physical modification, particularly hydrolysis, oxidation or hydrogenation and/or at least one purification step.
Preferably, the saccharide material is chosen from the group comprising monosaccharides, disaccharides, oxidised or hydrogenated derivatives of monosaccharides and disaccharides, and any mixtures of at least any two of these products, independently of the process by which such products were obtained.
Monosaccharides may consist, in particular, of pentoses or hexoses such as xylose, arabinose, ribose, glucose, galactose, mannose, sorbose or fructose.
Disaccharides may consist, in particular, of maltose, isomaltose, lactose, lactulose, cellobiose or sucrose.
As mentioned, the process according to the invention may also be applied to organic materials composed of purified or unpurified monosaccharides or disaccharides which have already been modified, particularly which have already been oxidised or hydrogenated.
The oxidised monosaccharides and disaccharides undergoing the characteristic step of enzymatic oxidation according to the invention may, in particular, correspond to the products of the oxidation, in one or more places, of the monosaccharides and disaccharides listed above and, in particular, may consist of any of gluconic, glucaric, 5-keto-gluconic, galactonic, galactaric, gulonic, maltobionic or lactobionic acids, said acids being in the free and/or lactonised and/or salt form.
The lactonised form may, by way of example, consist of a gluconolactone, a galactolactone or a gulonolactone.
The hydrogenated monosaccharides and disaccharides may, in particular, correspond to the products of relatively thorough catalytic hydrogenation of the above-mentioned monosaccharides and disaccharides.
It is widely known that monosaccharides or disaccharides, optionally oxidised or hydrogenated already, may be oxidised enzymatically, particularly by oxidoreductases capable of using oxygen as a hydrogen acceptor and hence capable of generating hydrogen peroxide (H
2
O
2
) in the reaction medium.
These are, in particular, enzymes of Group 1.1.3 as defined in the document “ENZYME NOMENCLATURE”, revised periodically by the International Union of Biochemistry and Molecular Biology. The nomenclature of such enzymes is recapitulated on pages 55 to 60 of the 1992 edition of said document.
These are, inter alia, enzymes having at least one of the glucose oxidase, hexose oxidase, galactose oxidase or pyranose oxidase activities.
BACKGROUND OF THE INVENTION
Thus, reference has been made regularly, particularly for about twenty years, to the use of pyranose oxidase (also known, inter alia, as “glucose 2-oxidase”, “pyranose: oxygen 2-oxidoreductase” or more simply “P2O”) for the enzymatic conversion of monosaccharides, optionally already oxidised, to their equivalents oxidised in the 2 position, and in particular for the conversion of glucose to glucosone or galactose to galactosone. These products are synthesis intermediates of great interest for obtaining products such as fructose, sorbitol, mannitol or tagatose which, on their own or in mixture, have wide fields of application, particularly in the food, pharmaceutical and chemical industries.
For several decades, there has also been wide recourse to the use of glucose oxidase (also known, inter alia, as “glucose oxyhydrase”, “beta-D-glucose: oxygen 1-oxidoreductase” or more simply “GOD”) for the preparation of gluconic acid, in the free, lactonised and/or salt form, from glucose.
However, one of the major disadvantages of the above-mentioned enzymes is that hydrogen peroxide is generated concomitantly and in equimolar quantities with the desired oxidised product. However, it is acknowledged that the presence of hydrogen peroxide is, on the whole, disadvantageous for the activity of an oxidoreductase such as pyranose or glucose oxidase, and efforts are generally made to remove hydrogen peroxide wholly or partly from the reaction medium during the course of the enzymatic oxidation reaction.
Various means of an enzymatic, chemical or physical nature have been proposed for removing or decreasing hydrogen peroxide or at least the adverse effects associated with the generation and presence of this compound in the complex medium which the enzymatic oxidation medium constitutes.
The means most often described consists in the use of catalase in the free or immobilised form, with a view to decomposing hydrogen peroxide enzymatically. This use is described in numerous patents such as the patents WO 81/03664 and WO 81/03666 published in 1981 in the name of STANDARD BRANDS, the subsequent patents U.S. Pat. Nos. 4,351,902, 4,423,149, 4,568,645, 4,569,910, 4,569,913, 4,569,915 and 4,650,758 in the name of CETUS CORPORATION, WO 97/24454 in the name of GENENCOR INTERNATIONAL INC and U.S. Pat. No. 5,897,995 in the name of GIST-BROCADES B.V.
The use of catalase in combination with a glucose oxidase has also been mentioned, where necessary also illustrated by examples, in the articles or patents below:
“STABILITY STUDIES ON THE IMMOBILIZED GLUCOSE OXIDASE/CATALASE ENZYME SYSTEM”, R. S. CARTER et al, ENZYME ENG., (1980), 5, 321-324,
U.S. Pat. No. 4,460,686, published in 1984 in the name of BOEHRINGER INGELHEIM,
“Production of gluconic acid with immobilized glucose oxidase in airlift reactors”, K. NAKAO et al, CHEMICAL ENGINEERING SCIENCE, (NOV. 1997), VOL. 52, no. 21-22, 4127-4133.
The use of catalase in combination with another oxidoreductase, namely a glycolate oxidase (EC 1.1.3.15), has also been illustrated by examples in U.S. Pat. No. 5,262,314 published in 1993 in the name of E.I. Du Pont de Nemours and Co.
The use of catalase has also been described, inter alia, in the following recent scientific articles:
“Laboratory procedures for producing 2-keto-D-glucose, 2-keto-D-xylose and 5-keto-D-fructose from D-glucose, D-xylose and L-sorbose with immobilized pyranose oxidase of
Peniophoro gigantea
”, A. HUWIG et al, Journal of Biotechnology 32, 309-315 (
Fleche Guy
Fouache Catherine
Fuertes Patrick
Moine Didier
Tamion Rodolphe
Henderson & Sturm LLP
Prats Francisco
Roquette Freres
LandOfFree
Process for the conversion of organic materials,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the conversion of organic materials,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the conversion of organic materials,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2946686