Glucose reaction products

Figure 18. Absorbance change with time of the toluidine glucose reaction product at...

Methylephedrine Bulk HPLC H,SO, Silica Methanolic 0.01 M also applicable to methyldopa-glucose reaction product [1121. 1123,1125,11271 [4.6J methods review [545] TLC [1] GC [2,264] [3]... 

ANTIOXIDATIVE EFFECT OF PEPTIDE-GLUCOSE REACTION PRODUCTS IN VITRO AND IN VIVO... 

The antioxidative effect of peptide-glucose reaction products prepared under various conditions against the oxidation of linoleic acid is shown in Table 1. The peptides pre-... 

Table 2. TBA value and chemiluminescent intensity (CL) of liver homogenate of rats fed with peptide-glucose reaction product and soybean paste...

PG Peptide-glucose reaction product group (n=5). SPC Soybean paste control (n = 7). 

The basic carbohydrate molecule possesses an aldehyde or ketone group and a hydroxyl group on every carbon atom except the one involved in the carbonyl group. As a result, carbohydrates are defined as aldehyde or ketone derivatives of polyhydroxy alcohols and their reaction products. A look at the formula for glucose shows that it contains hydrogen and oxygen atoms in the ratio in which they are found in water. The name carbohydrate... 

A mixture of methyl 3-deoxy-3-C-methyl-3-nitro-ct-D- and fi-L-glucopyranosides d l is formed by the reaction of nitroethane with the sugar thaldehyde obtained from L-glucose The products are separated and converted into branched-chain fluoro nitro l- and L-sugars fEq 361 ... 

Galactose, one of the eight essential monosaccharides (Section 25.7), is biosynthesized from UDP-glucose by galactose 4-epimerase, where UDP = uridylyl diphosphate (a ribonucleotide diphosphate Section 28.1). The enzyme requires NAD+ for activity (Section 17.7), but it is not a stoichiometric reactant. and NADH is not a final reaction product. Propose a mechanism. 

YOKDTA A, MiYATA K, MURAGUCHi H and TAKAHASHi A (1987) Effect of glucose on the antioxidative activity of Maillard reaction products during extmsion cooking , Nippon Nogeikagaku Kaishi, 61 (10) 1273-8. 

The addition of ammonia to the variety of acids derivable from either the breakdown of glucose, glycolysis, or of the pentose shunt reaction products, ribose and NADPH, and from the citrate cycle, gives the amino acids (see Table 4.7 and Figure 4.4) Polymerisation of amino acids in cells gives proteins. In some of the amino acids sulfur and selenium can be incorporated easily. We assume NH3 was present. (Note that Se is in a coded amino acid not in Table 4.7.) Some selective metal-binding properties can be seen in Table 4.7, but amino acid carboxylates can bind all. 

Depending on the immobilization procedure the enzyme microenvironment can also be modified significantly and the biocatalyst properties such as selectivity, pH and temperature dependence may be altered for the better or the worse. Mass-transfer limitations should also be accounted for particularly when the increase in the local concentration of the reaction product can be harmful to the enzyme activity. For instance H2O2, the reaction product of the enzyme glucose oxidase, is able to deactivate it. Operationally, this problem can be overcome sometimes by co-immobilizing a second enzyme able to decompose such product (e.g. catalase to destroy H202). 

The reaction between cellulose and acrylamide was studied by quantitative, chromatographic separation of the substituted D-glucoses obtained on acid hydrolysis of the reaction product,320 followed by an analysis by Spurlin s method.249 Although, apparently, no check was made on the stability of the ethers to the conditions of hydrolysis, it might be expected that the ethers would isomerize only under basic conditions. The ratios of the relative equilibrium-constants for reaction at 0-2, 0-3, and 0-6 were 9 1 19, and these are attributable to the high, relative stability of the primary ether, together with the low reactivity of 0-3, also observed in rate-controlled reactions. 

Irradiation of unprotected carbohydrates was the subject of greatest photochemical interest to the early carbohydrate photochemists.1 The investigations of these early workers were concerned primarily with the effect of reaction conditions upon the photochemical process, rather than with the identity of the reaction products. Between 1960 and 1969, a comprehensive series of papers was published on the photochemical reactions of D-glucose and D-glucitol.95-99 These studies contributed greatly to understanding of the photochemistry of unprotected carbohydrates, as not only was the result of variation in the reaction conditions studied but also the structures of the products were determined. 

Thermolysis of D-fructose in acid solution provides 11 and 2-(2-hydrox-yacetyl)furan (44) as major products. Earlier work had established the presence of 44 in the product mixtures obtained after acid-catalyzed dehydrations of D-glucose and sucrose. Eleven other products were identified in the D-fructose reaction-mixture, including formic acid, acetic acid, 2-furaldehyde, levulinic acid, 2-acetyl-3-hydroxyfuran (isomaltol), and 4-hydroxy-2-(hydroxymethyl)-5-methyl-3(2//)-furanone (59). Acetic acid and formic acid can be formed by an acid-catalyzed decomposition of 2-acetyl-3-hydroxyfuran, whereas levulinic acid is a degradation prod-uct of 11. 2,3-Dihydro-3,5-dihydroxy-6-methyl-4//-pyran-4-one has also been isolated after acid treatment of D-fructose.The pyranone is a dehydration product of the pyranose form of l-deoxy-D-eo f o-2,3-hexodiulose. In aqueous acid seems to be the major reaction product of the pyranone. 

Bailey AJ, Sims TJ, Avery NC and Halligan EP (1995) Non-enzymatic glycation of fibrous collagen reaction products of glucose and ribose. Biochem J 305, 385-390. 

---