Szent-Gyorgi

As long ago as the 1930s Rusznyak and Szent-Gyorgi proposed that the flavonoids were an essential dietary factor contributing to the maintenance... 

RUSZNYAK s and szent-gyOrgi a (1936) Vitamin nature of flavones . Nature, 139, 798. 

RA Steel, A Szent-Gyorgi. Proc Natl Acad Sci USA 43 477, 1957. 

Szent-Gyorgi, A. (1963). Lost in the twentieth century. Annu. Rev. Biochem. 32, 1-14. 

Szent-Gyorgi, A. (1944). Studies on muscle. Acta Physiol. Scand. 9, suppl. 25. 

The first suggestion that substrates in carbohydrate oxidation might exert catalytic effects on the oxidation of other intermediates (cf.earlier demonstration of such action in the urea cycle by Krebs and Henseleit, 1932 see Chapter 6) arose from the work of Szent-Gyorgi (1936). He demonstrated that succinate and its 4C oxidation products catalytically stimulated the rate of respiration by muscle tissues. He also observed that reactions between the 4C intermediates were reversible and that if muscle was incubated with oxaloacetate, fumarate and malate made up 50-75% of the products, 2-oxoglutarate 10-25% and, significantly, 1-2% of the C was converted to citrate. These observations were... 

When his studies on carbohydrate oxidation restarted in Sheffield, Krebs experiments included studies on the anaerobic dismutation of pyruvate by bacteria and various animal tissues. Assuming the role for the dicarboxylic acids postulated by Szent-Gyorgi, the main question was the route by which the carbon atoms of pyruvate were converted to succinate. In May 1936 Krebs had observed that if 2-oxoglutarate was added to pyruvate, the yield of succinate was enormously increased. In his notebook written that year (Holmes, 1993) Krebs postulated ... 

Besides Szent-Gyorgi and Krebs, other groups were attacking the problem of carbohydrate oxidation. Weil-Malherbe suggested It is probable that the further oxidation of succinic acids passes through the stages of fumaric, malic, and oxaloacetic acid pyruvic acid is formed by the decarboxylation of the latter and the oxidative cycle starts again. K.A.C. Elliott, from the Cancer Research Laboratories at the University of Pennsylvania, also proposed a cycle via some 6C acid. 

In the next 2 to 3 years further experiments, particularly by Eggleston, who had joined Krebs in January 1936, confirmed and extended the observations. Careful quantitative evaluation of the data indicated that citrate like fumarate (Szent-Gyorgi) and like ornithine in the urea cycle exerted a catalytic effect on muscle metabolism. If arsenite, which blocks 2-oxoglutarate oxidation, was added with citrate to a respiring pigeon-muscle preparation, 2-oxoglutarate accumulated. 

Dicarboxylic acid cycle discovered by Szent-Gyorgi. Krebs and Johnson. The tricarboxylic (citric) acid cycle. 

Lipmann. The High Energy Phosphate concept. Banga and Szent-Gyorgi. Actomyosin threads contracted in the presence of ATP. 

FUNK, CAS1M.IR 11884-1948). Bom in Poland and later becoming an American citizen. Funk in 1911 isolated a food factor, extracted from rice hulls, that he found to he a cure for a disease caused bv malnutrition (beriberi). Believing this to be an amine compound essential to life, he coined the name vilamine, from which the final e was later dropped. The various Ivpcs and functions of vitamins were not differentiated until some years later as a result of the work of McCollum, Szent-Gyorgi, R.J. Williams, and others. 

Szent-Gyorgi, A. (1957). Bioenergetics , Academic Press, New York, p. 39. 

Rusznyak, I.S. Szent-Gyorgi, A. 1936. Vitamin P Flavonols as vitamins. Nature 138 ... 

Ascorbic acid was isolated from cabbage, lemon juice, and adrenal glands by Szent-Gyorgy in 1928, and identified as the antiscorbutic factor by Waugh and King in 1932. Its structure was established by Haworth and coworkers in 1933, and the same year Haworth, in Birmingham, and Reichstein, in Switzerland, succeeded in synthesizing the vitamin. 

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