Glucose with pyruvic acid

Cornforth and coworkers and Gottschalk have expressed the view that the reaction of 2-amino-2-deoxy-n-glucose with pyruvic acid (and with 2,4-pentanedione) begins with the formation of a Schiff base [such as (85)], followed by an intramolecular aldol reaction to compounds (86). This interpretation cannot be extended to the reactions of nonnitrogenous sugars, and can only be applied in a modified way to the iV-alkylamino and M-arylamino sugars. Such compounds as (87) or (88) could be the... 

In order for the cell to carry out a controlled oxidation of D-glucose and conserve some of the energy derived from the process, it is lira necessary to add phosphate to the hexose with the expenditure of energy. The necessary energy and the phosphate per se is supplied by ATP in two separate reactions of the system. Since each molecule of glucose can yield two molecules of irioxe phosphate for oxidation, the conversion of glucose in pyruvic acid nets two molecules of ATP per molecule of hexose utilized. 

Do optically active 1-methyl-TIQs, as sketched in Fig. 32 for the synthesis of (7 )-salsolinol, originate from a Pictet-Spengler reaction of dopamine with acetaldehyde derive from ethanol, or are they the result of a Pictet-Spengler reaction of biogenic amines with pyruvic acid, as sketched in Fig. 33 Based on the accumulated data it seems reasonable to propose that optically active TIQs are formed by the pyruvic acid pathway, and that the pyruvic acids may be derived from an impaired glucose metabolism or an impaired amino acid metabolism. Whether the intermediate TIQ-1-carboxylic acids 91a,b are enzymatically decarboxylated to afford 64a,b in a different enantiomeric ratio, or whether optically active TIQs are formed by oxidative decarboxylation of TIQ 91 to DIQ 120, followed by an asymmetric reduction, remains open to question. 

Hb A with pyruvic acid attached to the N-terminal of the P-chain Hb A with glucose attached to the N-terminal valine of the P-chain Unstable Schiff base (aldimine) a labile intermediary component in the formation ofHbAic. 

It is reasonable to assume that other metabolically active substances such as D-glucose and pyruvic acid can also react with sodium sulfite. 

Aerobic glycolysis first involves a ten-step conversion of glucose to pyruvic acid or pyruvate, called the Embden-Meyerhoff-Pamas pathway, followed by its further conversion to carbon dioxide and water via what is variously called the tricarboxylic acid cycle, or citric acid cycle, or Krebs cycle after its discoverer. The net products discharged from the cycle are carbon dioxide and water, with recycle of a further product called oxaloacetic acid or oxaloacetate. Successive organic acids that contain three carboxyl groups (-COOH), are initially involved in the cycle starting with citric acid or a neutral salt of citric acid (citrate). Hence the designator tricarboxylic. 

Glycolysis The initial pathway in the catabolism of carbohydrates, by which a molecule of glucose is broken down to two molecules of pyruvate, with a net production of ATP molecules and the reduction of two NAD molecules to NADH. Under aerobic conditions, these NADH molecules are reoxidized by the electron transport chain under anaerobic conditions, a different electron acceptor is used. An anaerobic metabolic pathway used to break down glucose into pyruvic acid while producing some ATP. 

Carboxylic acids with labile a-methylene protons react with isatin in the presence of strong aqueous base. In the total synthesis of methoxatin, the coenzyme of methanol dehydrogenase and glucose dehydrogenase, Weinreb employs a Pfitzinger condensation of an isatin 37 and pyruvic acid as a key step to provide the 4-quinolinic acid 38 in 50% yield under the standard basic conditions. ... 

The next steps of glucose catabolism are called the citric acid cycle. The pyruvic acid formed in glycolysis is transported into the mitochondria, which arc subcellular organelles with double (inner and outer) membranes. They are referred to as the powerhous-... 

Reactions involve several enzymes, which have to follow in sequence for lactic acid and alcohol fermentation. This is known as the glucose catabolism pathway, with emphasis on energetic and energy carrier molecules such as ATP, ADP, NAD+ and NADH. In this pathway the six-carbon substrate yields two three-carbon intermediates, each of which passes through a sequence of reactions to the stable end product of pyruvic acid. 

Although no D-glucosone was obtained by the action of formaldehyde on D-glucose phenylosazone,19 Briill28 successfully decomposed the osazone with an excess of pyruvic acid. An improved procedure has been described, and the decomposition of D-glucose phenylosazone with glyoxal has been reported.18... 

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