Glucose 3-oxoglutarate

On heating the parent acid of ester VI (from condensation of D-glucose with diethyl 3-oxoglutarate) in aqueous solution,11 following the procedure employed to obtain the corresponding derivative of ethyl acetoacetate XXVI, a sirup results. However, its change in optical activity shows a parallelism with that in analogous cases where crystalline products are isolated, and apparently indicates anhydride formation (see the last line in Table V). 

The reactions of D-glucose with 2,4-pentanedione (acetylacetone), diethyl 3-oxoglutarate, ethyl benzoylacetate, ethyl propionylacetate, ethyl butyrylacetate, ethyl isovalerylacetate, and methyl acetoacetate have been effected, with formation of crystalline products. 

This helps to maintain the normal pH of the blood. The reactions also produce oxoglutarate, which can either be oxidised or be used to synthesise glucose (see below). 

Full details of the reaction are given in Appendix 8.4 and a detailed discussion of the role of the kidney in regulation of the acid/base balance is given in (Appendix 13.4). The oxoglutarate produced from these successive reactions is either oxidised to yield ATP or, under conditions of starvation, converted to glucose via gluconeogenesis (Figure 8.26). 

The further biosynthetic pathways from 3-phos-phoglycerate to the myriad amino acids, nucleotides, lipids, and miscellaneous compounds found in cells are complex and numerous. However, the basic features are relatively simple. Figure 17-11 indicates the origins of many substances including the 20 amino acids present in proteins, nucleotides, and lipids. Among the additional key biosynthetic precursors that can be identified from this chart are glucose 6-phosphate, pyruvate, oxaloacetate, acetyl-CoA, 2-oxoglutarate, and succinyl-CoA. 

Gaitonde M (1965) Rate of utilization of glucose and compartmentation of a-oxoglutarate in brain. Biochem J 95 803-810. 

Oxoglutarate, one of the substrates of hydroxylation, is supplied from glucose in the reaction medium via the EMP pathway and TCA cycle in E. coli and the product succinate is recycled. The mutant strain of E. coli which lacks L-proline-degrading enzyme was obtained and used for the host cells of production of L-hydroxyproline. 

The reaction, under the same conditions, has been extended to other /3-keto esters. Ethyl 3-oxovalerate, ethyl 3-oxohexanoate, and diethyl 3-oxoglutarate react with 2-amino-2-deoxy-D-glucose to give compounds (11), (12), and (13), respectively, whose oxidations with lead tetraacetate or periodic acid furnish the corresponding aldehydes (14), (IS), and (16). 

Additional information <1> (<1> no substrate 2-deoxy-D-ribose, 2-deoxy-D-glucose, o-gluconate, 2-keto-D-gluconate, 2-oxoglutarate, 2-oxo-3-deoxy-6-phosphogluconate [2]) [2]... 

Bakg + Bqaa- Abbreviations T, activity of the citric acid dele P, activity of the oxidative pentose phosphate pathway Glc6P, glucose 6-phosphate Fru6P, fructose-6-phosphate Gra3P, glyceraldehyde 3-phosphate PEP, phosphoenolpyruvate PYR, pyruvate AcCoA, acetyl coenzymeA OAA, oxaloacetate, AKG, 2-oxoglutarate... 

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