J-Arabinose

Dimethyl-J>arabinose (XXXVI) has been isolated from the products of hydrolysis of methylated araban94 and of methylated damson gum.97 It has been synthesized49 from methyl 5-trityl-L-arabofurano-sides (afi mixture) (XXXV) by methylation with methyl iodide and silver oxide followed by removal of the trityl group by means of hydrogen chloride in chloroform and hydrolysis of the methyl glycosides. ... 

Figure 4.21 The polypeptide chain of the arabinose-binding protein in E. coli contains two open twisted a/P domains of similar structure. A schematic diagram of one of these domains is shown in (a). The two domains are oriented such that the carboxy ends of the parallel P strands face each other on opposite sides of a crevice in which the sugar molecule binds, as illustrated in the topology diagram (b). [(a) Adapted from J. Richardson.)...

Figure 20 Post-column detection of mono- and disaccharides with 4-amino-benzoylbenzamide. Column CarboPac PA-1. Gradient 1-10 mm NaOH (0-20 min.), 10-20 mM NaOH (20-35 min). Flow rate 1 ml/min. Detection absorbance at 400 nm after reaction with 4-aminobenzoylhydrazide. (a) Standard mixture of fucose (1), arabinose (2), galactose (3), glucose (4), xylose and N-acetylglucosamine (5 and 6), allose (7), 3-fucosyllactose (8), fructose (9), lactose (10), Man-(3-(l,4)-GlcNac. (b) Normal urine, (c) Urine from a child with (3-mannosidosis. (Reproduced with permission of Academic Press from Peelen, G. O. H., de Jong, J. G. N., and Wever, R. A., Anal. Biochem., 198, 334, 1991.)...

These circumstances became apparent to the authors when they attempted to study the formation of KDO 8-phosphate as catalyzed by purified bacterial extracts. These extracts did not catalyze the formation of KDO 8-phosphate from D-ribose 5-phosphate, but required D-arabinose 5-phosphate as the substrate Heath and Ghalambor29 showed that the KDO 8-phosphate synthetase reaction, observed in Pseudomonas extracts by Levin and Racker, is also catalyzed by extracts from Escherichia coli strains 0 111 B4 and J-5. Rick and Osborn136 showed that the KDO 8-phosphate synthetase from a Salmonella typhimurium mutant conditionally defective in cell-wall synthesis had a KM of 6 mM as compared to a KM of 170 pM for the enzyme from wild-type cells. 

Fig. 2.106. Separation and identification of various anthocyanin red fruit juices a, grape b, blueberry c, raspberry and d, red currant. Mobile phase water-acetonitrile-formic acid (84 6 10, v/v). Abbreviations Dp delphidin, Cy cyanidin, Pt petunidin, Pn peonidin, Mv malvidin, glu glucose, gala galactose, ara arabinose, ruti rutinose, sopho sophorose, sam sambubiose, xyl xylose. Reprinted with permission from J.-P. Goiffon et al. [241].

Carbohydrates Ceiiuiose Starch 1 Hemiceiiuiose Lignin J ( monosaccharides "j ( hexoses "j Cx(H20)y < oligosaccharides > pentoses > [ chitin J ( glucosamine J (C2H20)4 unsaturated aromatic alcohols —> polyhydroxy carboxylic aoids HPOy, GO2, CH4, glucose, fructose, galactose, arabinose, ribose, xylose... 

Sherman, J.D. and Chao, C.C. (1984) Separation of arabinose by selective adsorption on zeolitic molecular sieves. U.S. Patent 4,516,566. 

O-Isopropylidene-D-erythrose ( ) (15), obtained either by acetonation of D-erythrose ( ) or by periodate oxidation of 3,4-0-isopropylidene-fi-arabinose (1, ]J), reacted with ethoxycarbonylmethy-lenetriphenylphosphorane in refluxing benzene (18) to give the E-alkene ( ) as the major product (56%) together with the Z -alkene ( ) (21%), As expected (1 -M) the alkenes (14) and (f5) readily cyclized to tetrahydrofurans (16) under very mild basic conditions. Initially the 6 anomer of (16) was favored C86% from (lA) and 100% from ( )] at equilibrium the a anomer preponderated (82%) (19). 

Further observations were published concerning 3,4- and 4,5-0-isopropylidene derivatives of D-arabinose and D-fructose.273 Thus, l,2 3,4-di-0-isopropylidene-/J-i>arabinose (266) gave a mixture of (—)-(S)-(Z)-5-butyl-3-nonen-l,2,5-triol (267), its (E) stereoisomer, and 4-... 

Xu, J., Whong, WZ. Ong, T.-M. (1984) Validation of the Salmonella (SV50)/arabinose-resis-tant forward mutation assay system with 26 compounds. Mutat. Res., 130, 79-86... 

Terminal L-arabinosidic linkages in L-arabinose conjugates are also hydrolyzed by the enzyme. The enzyme of R. fiava releases L-arabinose from the polysaccharide of the water shield (Brasenia schreberi J. F. Gmel)38 and from the cotyledon of Tora bean (Phaseolus vulgaris).39 Some 70 to 80% of the side chains of the arabinoxylan in rice cell-wall are composed of L-arabinose. When the a-L-arabinofuranosidase from R. 

J. Gelas and D. Horton, Acetonation of D-ribose and D-arabinose with alkyl isopropenyl ethers, Carbohydr. Res. 45 181 (197S). 

H. Zinner, G. Rembarz, and H. Klocking, Isopropyliden-verbindungen der D-arabinose-mercaptale, Chem. Ber. 90 2688 (1957) P. A. J. Gorin, Acetonation of aldose diethyl dithio-acetals. Can. J. Chem. 43 21X18 (1965) D. G. Lance and J. K. N. Jones, Acetonation of D-xylose diethyl dithioacetal, Can. J. Chem. 45 1533 (1967). 

L. Vargha and J. Kuszmann, 2-Chloro-2-deoxy-D-arabinose and -D-ribose. A new synthesis of 2 ilcoxy-D-crvr/iro-pcntose. Chem. Ber. 96 411 (1963). 

An anomeric carbon with an axial hydroxy group usually resonates at higher field than the corresponding C-1 with an equatorial hydroxy group (rule (5)). This rule allows one to prove, experimentally, that arabinose exists in the C4 and not in the 4C, conformation, in which most sugars occur in solution [88, 726]. However, rule (5) is not valid for the mannose, rhamnose and talose anomers. This was attributed to the presence of three closely spaced dipoles (Reeves effect) present in the /J-anomeric configuration of these three sugars [683, 684] (Fig. 5.7). 

The third enzyme in the pathway, KD0-8-phosphate phosphatase, has been purified to homogeneity (26). Because of its abosolute specificity, it should be a focal point for chemotherapeutic studies. jThe apparent for KD0-8-phosp te was+ etermined to be 5.8 x 10 M in the presence of 1.0 mM Co or Mg. This specific KD0-8-phosphate phosphatase was separated from enzymes, present in crude extracts, having phosphatase activity on other phosphorylated compounds by column chromatography on DGAE-Sephadex (26). Three distinct peaks of activity were detected. Fractions from each peak were pooled and the rates for the hydrolysis of five compounds were measured. Peak A possessed phosphatase activity for D-glucose-6-phosphate, D-arabinose-5-phosphate, D-ribose-5-phosphate and j-nitrophenylphosphate Peak B dephosphorylated D-arabinose-5-phosphate, D-ribose-5-phosphate and D-glucose-6-phos-phate. Peak C, which was well separated from the other two peaks, could only utilize KD0-8-phosphate as a substrate. KD0-8-phos-phate was not hydrolyzed by the phosphatases present in peaks A and B. 

Fry SC. 1982. Phenolic components of the primary cell wall. Feruloylated disaccharides of D-galactose and L-arabinose from spinach polysaccharide. Biochem J 203 493-504. 

Selective O-tritylation of a primary hydroxyl group of L-arabinose diethyl dithio-acetal (116) with trityl chloride and 4-dimethylaminopyridine (DMAP), successive benzylation with benzyl bromide, and O-detritylation with p-toluenesulfonic acid, followed by tosylation gave 2,3,4-tri-0-benzyl-5-0-tosyl-L-arabinose diethyl dithio-acetal (777), [a]J,8 —2° (chloCEoform). Cleavage of the diethyl dithioacetal group with... 

M. Helliwell, I. Phillips, R. G. Pritchard, and R. J. Stoodley, Asymmetric synthesis of (5S)-4-deoxy-5-C-(4-nitrophenyl)-L-threo-pentose and (5R)-5-C-(4-nitrophenyl)-L-arabinose, Tetrahedron Lett., 40 (1999) 8651-8655. 

N. Sperber, H. E. Zaugg, and W. M. Sandstrom, The controlled sodium amalgam reduction of aldonolactones and their esters to aldoses and an improved synthesis of D-arabinose, J. Am. Chem. Soc., 69 (1947) 915-920 and references cited therein. 

M. K. Singh, N. Prasad, and H. K. Sinha, Kinetics of oxidation of galactose and mannose with iodine in alkaline media, Asian J. Chem., 6 (1994) 636-640 (Chem. Abstr., 121 (1994) 179998y) M. K. Singh, N. Prasad, H. K. Sinha, and V. P. Singh, Kinetics and mechanisms of oxidation of arabinose and xylose by iodine in alkaline solutions, J. Indian Chem. Soc., 70 (1993) 74-75 (Chem. Abstr., 120 (1994) 107576) and references therein. 

The concentrations of DOC in major rivers typically range from 250 to 750 pM, and concentrations in the surface ocean range from 60 to 90 J.M (Table I). Most of the river data compiled in Table I are from the Amazon River system (Hedges et al., 1994, 2000), the Parana River system (Depetris and Kempe, 1993), and the Mississippi River (Benner and Opsahl, 2001). The seawater data are from surface water samples collected in the Pacific and Atlantic Oceans (see Table I for references). Total hydrolyzable neutral sugars (glucose, galactose, mannose, xylose, fucose, rhamnose, and arabinose) account for about 1-2% of river DOC and 2-6% of ocean DOC, indicating... 

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