Adolf Windaus

Adolf Windaus

Date of Birth: 25.12.1876
Country: Germany

  1. Biography of Adolf Windaus
  2. Research on Cholesterol and Vitamins

Biography of Adolf Windaus

Adolf Otto Reinhold Windaus was a German biochemist and organic chemist. He was born in Berlin to Adolf Windaus and Margaret (Elster) Windaus. His father came from a family of textile manufacturers, while his mother came from a family of craftsmen. Windaus received his secondary education at a French gymnasium in Berlin, where literature was mainly studied and science was given very little time. However, inspired by books on the discoveries in bacteriology made by Robert Koch and Louis Pasteur, Windaus decided to become a physician.

In 1895, Windaus began studying medicine at the University of Berlin. During this time, he also attended lectures by chemist Emil Fischer, whose interest in the application of chemistry in physiology impressed him. In 1897, after passing the entrance examination for medicine, Windaus continued his studies at the University of Freiburg. He studied chemistry under the renowned German chemist Heinrich Kiliani and, deciding to abandon his previous plans for a medical career, wrote a dissertation on the cardiac poisons of digitalis, for which he was awarded a doctoral degree in chemistry in 1899. After serving a year in military service in Berlin, Windaus returned to Freiburg, where he became a lecturer in 1903 and an assistant professor three years later. In 1913, he was appointed professor of applied medical chemistry at the University of Innsbruck in Austria, and in 1915, Windaus returned to Germany, assuming the position of professor of chemistry and director of the laboratory of general chemistry (now the Chemical Institute) at the University of Göttingen, where he worked for 29 years.

Research on Cholesterol and Vitamins

The main focus of Windaus' research was establishing the connection between biologically important chemical substances. Kiliani suggested that he study the structure of cholesterol. At that time, little was known about the structure and functions of this widely distributed substance, and Windaus believed that it must be closely related to other biological compounds known as "sterols." Sterols are complex organic compounds that do not contain nitrogen and consist of four flat rings with various side chains. They occur in various forms in the cells of animals, plants, and fungi. The most well-known sterol, cholesterol, was first discovered in a human gallstone. Cholesterol is often associated with heart disease and atherosclerosis, and it is found in large amounts in brain cells and the cortex of the adrenal glands. The level of cholesterol in the blood increases during pregnancy and decreases during infectious diseases.

In the early 1900s, Heinrich Wieland, while studying bile acids, isolated a compound called cholic acid. In 1919, Windaus obtained the same acid from cholesterol, thereby demonstrating the chemical affinity between cholesterol and bile acids. However, it remained unclear whether this chemical affinity corresponded to a biological connection. During this period of his scientific career, Windaus became interested in studying vitamins - organic substances necessary for the normal growth and vital activity of humans and animals. In 1897, Dutch physician Christiaan Eijkman described the disease beriberi, which is caused by a deficiency of certain unknown substances in the diet, one of which was later identified as thiamine (vitamin B1). In 1906, Frederick Gowland Hopkins demonstrated that "accessory food factors" play an essential role in maintaining the viability of organisms. Together with Polish chemist Casimir Funk, who named these substances vitamins, Hopkins formulated the concept that the absence of specific vitamins in the diet causes certain diseases.

In the early 1920s, the study of vitamins progressed rapidly, despite the complexity of their chemical analysis methods. However, the structure of vitamins remained unknown, and their characterization often relied on their physiological effects. It was already known that rickets, a disease in which children's bones soften, occurs predominantly in regions with little sunlight and can be treated with certain types of fat from fish liver, which contain a substance called vitamin D. Patients with rickets also recovered when treated with ultraviolet rays. In 1924, American physiologist Alfred Hess proved that certain foods exposed to ultraviolet rays also cured rickets. This discovery led to the theory of the existence of provitamins - substances that, under certain conditions, such as ultraviolet radiation, convert into vitamins. Analysis of food products exposed to ultraviolet radiation revealed that sterols are provitamins. Hess invited Windaus, a leading specialist in sterols, to New York to work together on determining the chemical structure of vitamin D and its provitamin. Windaus believed from the beginning that cholesterol was the provitamin of vitamin D since it exhibited the properties of vitamin D under ultraviolet radiation. However, the sample contained a small impurity, which in 1927 Hess and Windaus named ergosterol. Pure vitamin D, or calciferol, was obtained by exposing ergosterol to ultraviolet radiation. In 1932, Windaus and his colleagues demonstrated that another compound, 7-dehydrocholesterol, was also a provitamin, and this substance, named vitamin D3, was of the greatest importance since it is naturally produced in the bodies of animals and humans. The term "vitamin D1" was retained for the original mixture of calciferol and other sterols. Windaus later recalled, "No other vitamin was investigated by such strange and tortuous paths."

In 1928, Windaus was awarded the Nobel Prize in Chemistry "for his work on the constitution of the sterols and their connection with the vitamin group." In his introductory speech on behalf of the Royal Swedish Academy of Sciences, HG Sederbaum said: "As a result of Windaus' patient and highly qualified work, several digitalis glucosides and their compounds of plant origin have been obtained in pure form... Thus, it has been proven that these cardiac poisons are directly related, on the one hand, to cholesterol and bile acids, and on the other hand, to the cardiac poison of animal origin, bufotoxin, which was successfully studied by [Heinrich] Wieland." Sederbaum emphasized the significant importance of Windaus' research on vitamin D. Earlier, in collaboration with biochemist Franz Knoop, Windaus studied the reaction of sugars with ammonia, attempting to transform hydrocarbons into amino acids. However, the products of the reaction turned out to be derivatives of imidazole - a compound containing a ring of three carbon atoms and two nitrogen atoms. Analysis of these substances revealed the amino acid histidine and the compound histamine, which causes the dilation of blood vessels and, as now known, plays a role in the development of allergies and inflammatory processes. These studies were of interest to the IG Farbenindustrie concern and other German chemical-pharmaceutical companies, which provided Windaus with everything necessary for further research and set him tasks requiring resolution.

Two Dutch chemists, BKP Jansen and WF Donath, proposed that vitamin B1, or thiamine, contained an imidazole ring. Windaus was able to prove that this vitamin contained not only thiazole and pyrimidine rings but also sulfur, but it lacked an imidazole ring. Later, the scientist studied the structure of colchicine, used in the treatment of cancer, and the stereochemistry of ring structures. Windaus' establishment of the structure of the sterol ring in 1932 allowed his assistant Adolf Butenandt to explain the structure of sex hormones. Despite being opposed to the Nazi party and Adolf Hitler's politics, Windaus' position as a scientist protected him and allowed him to continue his research without interference. After 1938, he ceased scientific research, and in 1944, he retired from the university.

In 1915, Windaus married Elizabeth Resau, and they had two sons and a daughter. The scientist passed away at the age of 82 in Göttingen in 1959.

Windaus received numerous awards, including the Louis Pasteur Medal from the French Academy of Sciences (1938), the Goethe Medal from the Goethe Institute (1941), and the German Grand Order of Merit with Star (1956). He was also honored with honorary degrees from the University of Göttingen, the University of Munich, the University of Freiburg, and the University of Hanover.