NENCKI, Marceli

N. finished the gymnasium in Piotrkówo in 1863 and began studying at the Jagiellonian University in Krakow. After a year, he left for Jena and began studying at the Faculty of Arts of the local university, choosing classical languages as the main subject. Due to the persuasion of two doctors, he finally left for Berlin and studied medicine at the local university. In 1870, he finished the study of medicine with the dissertation Oxidation of Aromatic Compounds in Animal Organisms (Die Oxydation der aromatischen Verbindungen im Tierkörper). Already during his studies, he was a member of the Technical College in Berlin, which enabled him a two-year practice at the laboratory of Johann Friedrich Wilhelm Adolf von Baeyer, and work under his guidance. Two years after finishing his study, he was employed as an assistant at the Institute of Pathological Anatomy of the University of Bern. In 1876, barely a 29-year-old, he occupied the post of associate professor, and was in recognition of his merits given to manage the newly established Chair of Physiological Chemistry (Biochemistry) at the University of Bern. In these years, N. proved to be one of the most important Swiss scientists. In 1891, he moved to St. Petersburg and became engaged in experimental medicine at a newly established institute. He was appointed head of the Department of Chemistry, which was created in only a year, thanks to his efforts. In co-operation with the known leader of the Institute, Iwan Pietrowicz Pawłow, his most important works in the field of organic chemistry, physiological chemistry, and bacteriology were created. He was thus able to link his research in the field of organic chemistry with his medical education. The research mostly referred to uric acid, diamide of carbonic acid, ketone guanine, oxyketones and their derivatives. N. conducted research with the use of syntheses, describing the molecular structure of these substances; the research proved to be of great importance to the dyestuff manufacturing industry and to the analytical methods of pharmacology. During his research into the products of the condensation of carbolic acid with the aid of various substances, he managed to produce the first synthetic antiseptic, phenyl salicylate, a substance that was later used for various purposes. The dissertation he wrote in Berlin, in which he described the metabolism of benzoate compounds within an organism, was the first of a series of treatises in the field of biochemistry. On the basis of this research, together with Sieberowa, he developed a biometric test for checking the intensity of the oxidation process in an organism, which is still used today. This test enabled him to explain the characteristics of diabetes. In co-operation with Sieberowa, he discovered that diabetes is not the result of the prevention of oxidation processes, but of those that convert sugar into lactic acid. N. also proved that the presence of a carboxyl group substantially reduces the toxicity of aromatic compounds in organisms. His works in this field are the basis for an important field in chemistry – detoxification of an organism. His research of many years regarding the origin of urea was also of great importance. He discovered that a diamide of carbonic acid can be created in a cell with the aid of aminocarbonic acid supplied to the organism, although at the time the general opinion was that cells create proteins, from which they are then separated by dissolution. N. noticed that ammonia binds with carbon dioxide, which is created by combustion, thus creating ammonium carbonate. The carbonate releases a molecule of water and changes into carbamide acid, which in turn changes into a diamide of carbonic acid. This theory was prevalent in the scientific realm until the research of Hans Adolf Krebst in the 1930s. This basically confirmed N.'s statements. He also achieved great success with his research regarding haemoglobin. Together with Sieberowa and J. Zaleski, he developed a method of obtaining the hemin crystal as a source material for further research. From this, N. obtained crystal haematoporphyrin and after numerous analyses determined its chemical structure. The next substance he obtained from the hemin crystal was mesoporphyrin, a substance that according to its chemical structure was a link between haemoglobin and chlorophyll, a plant pigment, which was at that time researched by Leon Pawel →Marchlewski. This research led him to the thesis that both pigments, which are very important in nature, point to a similar structure. N. was also engaged in the research of proteins and enzymes. He was the first to discover aminocarbonic acid, which he identified as aminoacetic acid. In actuality, it was tryptophan, which was discovered a few years later by Frederick Gowland Hopkins. N. researched the chemical structure of proteins, determining their disintegration under the influence of alkanes, acids, digestive juices, and sporogenic bacteria. During this research, he formed the first classification of aminocarbonic acids in proteins, which is a standard in 20th century biochemistry.
In the field of bacteriology, N. is known as a pioneer of the physiology and chemistry of microorganisms. He was the first to conduct biochemical experiments on bacteria.