Z-Arabinose

Neufeld, E.F., Feingold, D.S., and Hassid, W.Z. (1958) Enzymatic conversion of uridine diphosphate D-glucuronic acid to uridine diphosphate galacturonic acid, uridine diphosphate xylose, and uridine diphosphate arabinose. JAmer.Chem.Soc. 80 4430 Northcote, D.H. (1985) Control of cell wall formation during growth. In Biochemistry of Plant Cell Walls, edited by C.T. Brett, et al, pp. 177-197. Cambridge University Press, Cambridge. 

C5HuN05 L-Arabinose st/n-oxime (SARBOX)243 P21212I Z = 4 D = 1.61 R = 0.04 for 1,387 intensities. The acyclic molecule has the planar, zigzag conformation. The terminal OH and N-OH groups are oriented—syn and ap, respectively. Despite the difference in crystal symmetry, the hydrogen bonding is remarkably similar to that of the anti compound (see preceding abstract), with the same spiral of O-H N bonds. 

Figure 28.5, illustrates TLC of an urine sample by the normal TLC-technique vis-a-vis the wedged-tip technique (Figure 28.5(Z>)). One may clearly visualize the beautiful separated bands in the latter as compared to the several odd and irregular-shaped spots in the former. Both the clarity of separation and the reproducibility of the results are predominant in the latter technique. Figure 28.5 (a) and (b) represent the typical analysis of a urine sample containing glucose, arabinose, lactose and fructose respectively.

Levoglucosan 14, which is derived from Z)-glucose, has a strained ether ring system. Oxidation in methanol causes carbon-carbon bond cleavage to yield D-arabinose. High yields are obtained in methanol with addition of sodium methoxide... 

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, W.-Z. Ong, T.M. (1984) Validation of the Salmonella (SV50)/arabinose-resistant forward mutation assay system with 26 compounds. Mutat. Res., 130,79-86... 

Als Epimere wurden urspriinglich Aldosen bezeichnet, die sich nur in der Konfiguration an C-2 unterscheiden, wie z. B. D-Glucose und D-Mannose, die bei der Reaktion mit Phenylhydrazin folglich dasselbe Osazon ergeben oder beim Abbau von C-l zu derselben Pentose, in diesem Fall D-Arabinose, umgewandelt werden. 

Zhou, Z., Ribeiro, A.A., Lin, S., Cotter, R.J., Miller, S.I., Raetz, C.R. Lipid A modifications in polymyxin-resistant Salmonella typhimurium PMRA-dependent 4-amino-4-deoxy-L-arabinose, and phosphoethanolamine incorporation. 1 Biol Chem 276 (2001) 43111—43121. 

The five E. coli genes inserted in Z. mobilis allowed the entry of arabinose into the nonoxidative phase of the pentose phosphate pathway (Fig. 14-22), where it was converted to glucose 6-phosphate and fermented to ethanol. 

Horton et al. were interested in the synthesis of tetra-C-substituted carbocycles, and extensively studied asymmetric Diels-Alder reactions employing acyclic unsaturated carbohydrate derivatives. Thus, the thermal cycloaddition of the D-arabinose-derived c/i-dienophile (Z)-100 with cyclopentadiene gave endo-adduct 101 in excellent optical purity. The high diastereo-facial differentiation in this reaction arises from a highly favored conformation at the allylic center [76,77] (Scheme 10.33). Therefore, conformer 102 seems to be more favored than 103, where the latter suffers from severe allylic strain between the methoxycarbonyl and the C4-acetoxy group... 

Figure 7. Production of polyketide intermediates by Epo Mod345-TE expressed in E. coll A, LC/MS/MS (MRM, m/z 282/ 264) of synthetic standard, compound B (Fig. 5). B, LC/MS/MS of extract from E. coli strain K207 3 with plasmids pKOS455-042 (epo mod3 4-5-TE) andpG-KJE8 (groES, groEL, dnaJ, dnaK, grpE) following induction with L-arabinose and 4 days incubation at 22°C.

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