LEBEDEV, ALEKSANDR NIKOLAEVICH

(b. MOSCOW, Russia, 21 May 1881; d. Moscow, 3 June $$$)

biochemistry.

After graduating from a classical gymnasium in Moscow, Lebedev entered the Faculty of Natural Sciences at Moscow University in 1897. Upon receiving his bachelor’s degree in 1901, he became an assistant in the chemical laboratory of N. D. Zelinsky at the university. There he became interested in catalysis and the occurrence of catalytic phenomena in living forms.

Already possessing an exceptional chemical background, Lebedev decided to expand his biological and agronomical education while continuing his work at Zelinsky’s laboratory by enrolling in the Petrov-Rasumov (today the Timiriazev) Agricultural Institute, from which he received a master’s degree in agronomy (1904).

Lebedev was sent abroad in the year 1905-1906 to train for the professorship. He worked with Georg Bredig in Heidelberg, where he conducted his first research on the influence of a high-frequency current on hydrogen peroxide. In 1907 he went to Berlin, where he worked in the laboratory of Eduard Buchner at the University of Berlin. For a few months in 1910 he worked with Emil Fischer at his Institute of Organic Chemistry, also at the University of Berlin.

In Buchner’s laboratory Lebedev began his lengthy research on the chemical nature of alcohol fermentation. At that time the discussions resulting from contradictions in the opinions of Louis Pasteur, Marcellin Berthelot, and Moritz Traube had not been forgotten, and the conception that the chemical metabolic processes in the cell could be represented as a chain of connected biocatalytic reactions was being increasingly affirmed. Lebedev studied the kinetics of alcoholic fermentation, then began to search for intermediate products of the conversions of sugar in the process of alcohol fermentation. He was seeking to determine a general scheme of these processes, something that Adolf von Baeyer and Eduard Vohl had already attempted to do, but unsuccessfully and only speculatively. Lebedev’s intense work in the laboratory led to a hemorrhage in his eye and an exacerbation of existing tuberculosis. He discontinued his work in the laboratory and went to Palermo, Sicily where he began to summarize the data he had collected.

In 1911 Lebedev continued his research on fermentation at the Pasteur Institute’s biochemical section, headed by Gabriel Bertrand. Here he developed a method for obtaining the enzyme of fermentation, zymase, from dry yeast. (More precisely, zymase is an enzyme complex inducing extracellular fermentation of sugars.) This method of maceration became the classical one, displacing Buchner’s method. Lebedev read a paper on this work before the Paris Chemical Society, which awarded him its prize for it.

Upon his return to Russia, Lebedev was given a teaching position at the Don Polytechnical Institute in Novocherkassk. While there, he published his most important articles on the chemical nature of fermentation, and he summarized his research in Khimicheskie issledovaniia nad vnekletochnym spirtovhym brozheniem (Chemical research on extracellular alcohol fermentation, 1913), which he presented to Moscow University for the doctorate in chemistry. This work received the University Award, and in 1914 Lebedev elected professor of the highest order at the Don Polytechnical Institute.

In 1911 Lebedev showed that dihydroxyacetone is fermented by yeast juice; and in 1912, with N. Griaznov, he established that for fermentation to occur, the enzyme reductase was required, the activity of which was induced by a thermostable coenzyme. This coenzyme could be separated from zymase by means of dialysis, and the addition of the dialysate of a small quantity of boiled yeast juice restored the initial activity of zymase that was lost during dialysis. Lebedev obtained osazones of intermediate products of fermentation, and he identified them as hexose-phosphorus ethers.

In 1909 Lebedev proposed the first scheme of alcohol fermentation, with the main role in this process being played by trioses: glyceraldehyde and dihydroxyacetone. In 1912 Lebedev clarified this scheme, including in it triose phosphates as indispensable intermediate products of the anaerobic decomposition of carbohydrates. This scheme was confirmed by Otto Meyerhof and Gustav Embden.

In 1921 Lebedev moved to Moscow as professor of agronomy at Moscow University (where he worked until his death). At the same time he became a member of the Scientific Research Institute of the university. From 1930 he headed the biochemical laboratory of the Central Scientific Research Food Institute, and from 1935 he headed the biochemistry laboratory of the All-Union Institute of Experimental Medicine in Moscow.

BIBLIOGRAPHY

I. Original Works. “Über Hexosephosphorsäureester,” in Biochemische Zeitschrift, 28 (1910), 213–229; “Extraction de la zymasepar simple maceration,” in Comptes rendus de l’ Académíc des sciences (paris), 152 (1911), 49–51 – “Über den Mechanismus der alkoholischen Gärung,” in Biochemische Zeitschrift, 46 (1912), 483–489; and Khimicheskie issledovaniia nad vnekletochnym spirtovnym brozheniem (Chemical research on extracellular alcohol fermentation; Novocherkassk, 1913)

II. Secondary Literature. Anatoly Bezkorovainy. “Contributions of Some Early Russian Scientists to the Understanding of Glycolysis,” in Journal of the History of Medicine, 28 , no. 4 (1973), 388–392.

A. N. Shamin