Rihard Wilshtetter

Rihard Wilshtetter

Chemist
Date of Birth: 13.08.1872
Country: Germany

Biography of Richard Willstätter

Richard Martin Willstätter, a German chemist, was born in Karlsruhe in the family of textile merchant Max Willstätter and Sophie (Ullmann) Willstätter. He completed school in Karlsruhe and the Realgymnasium in Nuremberg, where he excelled academically and was recommended by the rector to attend the prestigious Royal College in Munich. However, he was denied admission because he was Jewish. In 1890, after finishing the Realgymnasium, Willstätter enrolled at the Munich Technical University to study chemistry. However, he was disappointed with the level of education there and transferred to the laboratory of Adolf von Baeyer at the University of Munich. Baeyer recommended Willstätter to his colleague Alfred Einhorn. Thus, working under Einhorn on the structure of cocaine and related compounds, Willstätter began his career as a researcher. In 1894, he obtained a doctorate in chemistry and two years later became a lecturer, and in 1902, an extraordinary professor, in Baeyer's laboratory. In 1905, Willstätter took the position of professor of chemistry at the Federal Institute of Technology in Zurich. It was in Zurich that he began his research on chlorophyll, the green pigment found in almost all flowering plants, mosses, ferns, and algae. Chlorophyll plays an important role in photosynthesis, the process by which green plants convert carbon dioxide and water into sugar, starch, and oxygen under the action of light. At the time Willstätter started his research, the structure of chlorophyll was not fully understood. In 1906, it was hypothesized that each individual plant contained multiple types of chlorophyll, making it difficult to determine the chemical nature of photosynthesis since data obtained from experiments on one species of plant might not be valuable to researchers studying other species. Willstätter and his student Arthur Stoll made significant contributions to solving this problem. They demonstrated through meticulous analysis, mainly using nettle leaves as a readily available and abundant source of chlorophyll, that chlorophyll had one main structure (tetrapyrrole, a compound consisting of four pyrrole rings linked to a central magnesium atom). Furthermore, they established that although chlorophyll had one main structure, there were two almost identical forms, designated as chlorophyll a and b. Continuing their work, Willstätter and Stoll demonstrated the universality of chlorophyll a and b by analyzing over 200 plant species. They demonstrated that there was one fundamental chlorophyll structure present worldwide. From this, they concluded that the chemical reactions involved in photosynthesis were the same everywhere. The discovery made by Willstätter and Stoll had implications for interpreting conflicting results obtained by previous researchers studying chlorophyll. They stated that these studies were conducted "with impure chlorophyll. Actually, it was not chlorophyll at all." In 1912, at the insistence of his friend Hans Fischer, Willstätter joined the newly established Kaiser Wilhelm Institute in Berlin, where he continued his research on anthocyanins. Most of the red, blue, and violet pigments in plants consist of anthocyanins, compounds that can be extracted from plants using alcohol, ether, or water. For example, it is the anthocyanins that give a red color to boiling beetroot water. Willstätter discovered that compounds with the same structure soluble in water could produce different colors. He found that the color of most plant flowers was determined by just three anthocyanins, which differed only in the number of hydroxyl groups on one ring of water-soluble structures. Flower coloration depended on the mixture of several anthocyanins and, for yellow coloration, carotenoids. Willstätter's research on anthocyanins was interrupted by the outbreak of World War I in 1914. Due to injuries sustained a few years earlier while mountaineering, he was exempted from military service. In 1915, Willstätter was awarded the Nobel Prize in Chemistry "for his research on the coloring matters of plants, especially chlorophyll." Due to the cancellation of award ceremonies during the war, he received the prize only in 1920. In his Nobel lecture, he stated, "The aim of my work was to establish the structural characteristics of the most widely distributed pigments of plants, especially chlorophyll, and to find definite criteria concerning their chemical function." Willstätter's work on chlorophyll and anthocyanins demonstrated that the diversity of plant pigments is based on only a few chemical compounds. By relating this fact to the study of chlorophyll, he argued that the biochemical basis of photosynthesis must be universal and therefore should be subject to scientific analysis. In 1916, Willstätter was appointed professor at the University of Munich, succeeding Baeyer. However, after the end of World War I, scientific life in Germany faced many difficulties due to rampant inflation and political instability. Nevertheless, Willstätter chose a new direction of research to "break into the unknown" and embarked on the study of enzymes, about which he and his colleagues knew almost nothing. By 1924, however, anti-Semitism had significantly intensified, and several Jewish candidates for university positions, including Willstätter, were not hired. Willstätter himself was appointed as the university official responsible for the refusal to hire candidates of Jewish origin. In response, on July 24, 1924, in protest, Willstätter resigned. He was succeeded at the university by Heinrich Wieland, who provided Willstätter with the opportunity to continue experimental work with leukocytes for several subsequent years. With the rise of the Nazis to power in 1933, Willstätter's life became more complicated. After Adolf Hitler became Chancellor of Germany, Willstätter visited the United States and Great Britain. He was repeatedly offered positions related to scientific research and teaching there but declined these offers, wishing to remain in his homeland. In November 1938, the police came to his home to arrest him and send him to Dachau, the first concentration camp in fascist Germany. However, Willstätter's housekeeper managed to divert the police to the garden, where he was hiding at the time. In early the following year, Willstätter attempted to flee to Switzerland, where his former student Arthur Stoll offered him shelter. However, when Willstätter crossed Lake Constance on a boat, he was captured by the Gestapo. Later, after the intervention of the Swiss ambassador, Willstätter was allowed to leave Germany. In Switzerland, Stoll provided him with the opportunity to settle in Villa "Eremo," located near Locarno, where Willstätter lived until the end of his days. There, he wrote his autobiography, titled "From My Life," which was published in England in 1965. In 1903, Willstätter married Sophie Leser. They had a son and a daughter. Willstätter's wife passed away in 1909, and he never remarried. The scientist died of heart disease on August 3, 1942, just one day before his 70th birthday. As the English chemist Robert Robinson writes, Willstätter "was a great experimenter and a great inventor of experiments. However, his greatest talent as a researcher lay in his ability to organize work." Willstätter loved and deeply respected Jewish national culture while maintaining strong connections with the musical, literary, and intellectual life of Germany. In addition to the Nobel Prize, Willstätter was awarded the Davy Medal of the Royal Society of London (1932) and the Willard Gibbs Medal of the American Chemical Society (1933). He received honorary degrees from the University of Oxford, the University of Manchester, and the University of Paris. He was a foreign member of the Royal Society of London and an honorary member of the British Chemical Society.

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