154368-11-3Relevant academic research and scientific papers
(13C)-substituted sucrose: 13C-1H and 13C-13C spin coupling constants to assess furanose ring and glycosidic bond conformations in aqueous solution.
Duker,Serianni
, p. 281 - 303 (1993)
Sucrose (beta-D-fructofuranosyl alpha-D-glucopyranoside, 1), methyl alpha-D-fructofuranoside (2), and methyl beta-D-fructofuranoside (3) have been prepared by chemical and/or enzymic methods with single sites of 13C-substitution at C-1, C-2, C-3, and C-6 of the fructofuranosyl ring. 1H (500 MHz) and 13C (75 and 125 MHz) NMR spectra of 1-3 have been obtained, yielding 1H-1H, 13C-1H, and 13C-13C spin coupling constants that were used to assess furanose ring and glycoside bond conformations in aqueous (2H2O) solution. Results show that the conformational mobility of the furanosyl ring in 3 is altered when incorporated into 1. Furthermore, 13C-13C and 13C-1H spin couplings across the glycosidic linkage suggest a psi torsion angle different from that observed in the crystal (phi appears similar). Interplay between the strength of the exoanomeric effect and hydrogen bonding in solution may be responsible, in part, for the apparent conformational flexibility of 1. In addition, spin couplings in 2 and 3 have been compared to those measured previously in alpha-D-threo-pentulofuranose (4) and beta-D-threo-pentulofuranose (5), respectively, as a means to study the effect of glycosidation and hydroxymethyl substitution on the solution conformation of the 2-ketofuranose ring. The conversion of 4 to 2 is accompanied by minimal conformational change, whereas a significant change accompanies the conversion of 5 to 3, showing that the effect of substitution on ring conformation depends highly on ring configuration before and after substitution.
Characterization of Recombinant Sucrose Synthase 1 from Potato for the Synthesis of Sucrose Analogues
Roemer, Ulrike,Nettelstroth, Nadja,Koeckenberger, Walter,Elling, Lothar
, p. 655 - 661 (2007/10/03)
The characteristics and the application of recombinant sucrose synthase 1 (SuSy1) from potato for the synthesis of sucrose analogues are described. With UDP-Glc as donor substrate SuSy1 accepts a variety of ketoses, e.g., 1-deoxy-1-fluoro-D-fructose (6; 100%), L-sorbose (7, 55%), and D-xylulose (8; 42%), as well as aldoses, e.g., D-talose (15; 36%), D-idose (16; 24%), D-lyxose (12; 48%), L-arabinose (13; 36%), and D-ribose (14; 7%). Kinetic analyses revealed that the non-natural acceptors 6 (kcat/ Km = 3.5 s-1 mM-1), 7 (kcat/Km = 1.10-2 s-1 mM-1), 8 (kcat/Km = 2.10-2 s-1 mM-1), and 12 (kcat/Km = 2.10-2 s-1 mM-1) were relatively poor substrates when compared to D-fructose (5; kcat/Km = 34.1 s-1 mM-1). It is concluded that the configuration and/or presence of the hydroxymethyl group at C5 determine the affinity of the ketoses for SuSy1. The acceptance of aldoses can be explained by their flexible chair conformations, which lead to isosteric hydroxy groups recognized by SuSy1. The preparative synthesis of sucrose analogues yielded 1′-deoxy-1′-fluoro-β-D-fructofuranosyl-α-D- glucopyranoside (1), [13C1]-β-D-fructofuranosyl-α-D-glucopyranoside (2), α-D-glucopyranosyl-α-L-sorbofuranoside (3), and α-D-glucopyranosyl-α-D-lyxopyranoside (4), in a 0.1-1.0 g scale. The sucrose analogues 1, 3, and 4 were not hydrolyzed by invertase, which makes them valuable tools for studies on signal transduction pathways and sugar transport in plants.
