title: Carbon-13-enriched carbohydrates: preparation of triose, tetrose, and pentose phosphates.
abstract: Three-, four-, and five-carbon aldononitrile phosphates were prepared, purified, and catalyticlly reduced with palladium--barium sulfate (5%) to the corresponding aldose phosphates in high yields at pH 1.7 +/- 0.1 and atmopsheric pressure. DL-Glyceraldehyde 3-phosphate and the tetrose 4-phosphates were prepared with carbon-13 enrichment at C-1, while the pentose 5-phosphates were prepared with enrichment at C-1 and C-2. Preparations of glycolaldehyde phosphate and d-glyceraldehyde 3-phosphate by lead tetra-acetate oxidation of glycerol phosphate and fructose 6-phosphate, respectively, are described. The proportions of cyclic hemiacetals and linear gem-diol forms of the two- to five-carbon aldose phosphates in aqueous solution are reported. Carbon-13 chemical shifts and carbon--phosphorus and carbon--hydrogen coupling constants for the furanose phosphate ring and linear gem-diol phosphates are reported and discussed. d-[2(-13)C]Ribulose 1,5-bisphosphate and L-[3,4(-13)C]sorbose 1,6-bisphosphate were prepared enzymatically from D-[2(-13)C]ribose 5-phosphate and dl-[1(-13)C]glyceraldehyde 3-phosphate, respectively.
mesh_terms: D002238:Carbohydrate Epimerases; D002247:Carbon Isotopes; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D010428:Pentosephosphates / Q000138:chemical synthesis*; D010770:Phosphotransferases; D012267:Ribosemonophosphates; D012274:Ribulosephosphates; D013329:Structure-Activity Relationship; D013403:Sugar Phosphates / Q000138:chemical synthesis*; D013780:Tetroses; D014305:Triose-Phosphate Isomerase; D014306:Trioses
chemical_list: D002247:Carbon Isotopes; D010428:Pentosephosphates; D012267:Ribosemonophosphates; D012274:Ribulosephosphates; D013403:Sugar Phosphates; D013780:Tetroses; D014306:Trioses; D010770:Phosphotransferases; D002238:Carbohydrate Epimerases; D014305:Triose-Phosphate Isomerase