Leopold Ružička

Ružička was born in Vukovar (until 1918 in the Austria-Hungary, today in Croatia). His family of craftsmen and farmers was mostly of Croat origin,His great-grandparents included a Czech, from whom the name Ružička stems, an Upper Austrian and his wife from Wurtemberg, the other five being Croats with a Czech great-grandparent, Ružička, and a great-grandmother and a great-grandfather from Austria.{{cite book|editor-first = Karl|editor-last = Grandin|chapter = Leopold Ružička|title = Nobel Lectures, Chemistry: 1922–1941|publisher = Elsevier Publishing Company|location = Amsterdam|year = 1966}}
Now available from {{cite web|url = http://nobelprize.org/nobel_prizes/chemistry/laureates/1939/ruzicka-bio.html|title = Leopold Ružička Biography|website = nobelprize.org|publisher = Nobel Foundation|year = 1939|access-date = 6 July 2017}} He lost his father, Stjepan, at the age of four, and his mother, Amalija Sever, took him and his younger brother Stjepan, to live in Osijek.

Ružička attended the classics program secondary school in Osijek. He changed his original idea of becoming a priest and switched to studying technical disciplines. Chemistry was his choice, probably because he hoped to get a position at the newly opened sugar refinery built in Osijek.

Owing to the excessive hardship of everyday and political life, he left and chose the High Technical School in Karlsruhe in Germany. He was a good student in areas he liked and that he thought would be necessary and beneficial in the future, which was organic chemistry. That is why his physical chemistry professor, Fritz Haber (Nobel laureate in 1918), opposed his summa cum laude degree. However, in the course of his studies, Ružička set up excellent cooperation with Hermann Staudinger (a Nobel laureate in 1953). Studying within Staudinger's department, he obtained his doctoral degree in 1910, then moved to Zürich as Staudinger's assistant.

Ružička's first works originated in the field of chemistry of natural compounds.{{Cite web|url=http://chemindigest.com/leopold-ruzicka-1887-1976/|title = Leopold Ruzicka (1887–1976)|date = 26 October 2018}} He remained in this field of research all his life. He investigated the ingredients of the Dalmatian insect powder Pyrethrum (from the herb Tanacetum cinerariifolium), a highly esteemed insecticide found in pyrethrins, which were the focus of his work with Staudinger. Ružička later said of this time: "Toward the end of five and a half years of mainly synthetic work on the pyrethrins I had come to the firm conclusion that we were barking up the wrong tree." In this way, he came into contact with the chemistry of Terpineol, a fragrant oil of vegetable origin, interesting to the perfume industry. He and Staudinger split company when he started cooperation with the Chuit & Naef Company (later known as Firmenich) in Geneva.Albert Eschenmoser: "Leopold Ruzicka – From the Isoprene Rule to the Question of Life's Origin" CHIMIA 44 (1990)

In 1916–1917, he received the support of the oldest perfume manufacturer in the world Haarman & Reimer, of Holzminden, Germany. He became a Swiss citizen in 1917, and published his Habilitation in 1918. Fornasir and he isolated linalool in 1919.

With expertise in the terpene field, he became senior lecturer in 1918, and in 1923, honorary professor at the ETH (Eidgenössische Technische Hochschule) as well as the University of Zurich. Here, with a group of his doctoral students, he proved the structure of the compounds muscone and civetone, macrocyclic ketone scents derived from the musk deer (Moschus moschiferus) and the civet cat (Viverra civetta).{{cite book|title = The Chemistry of Fragrances|editor1-last = Pybus|editor1-first = David H.|editor2-first = Charles S.|editor2-last = Sell|pages = 51–124|chapter-url = https://books.google.com/books?id=u_b7-qY2xT8C&pg=PA91|publisher = Royal Society of Chemistry Publishing|year = 1999|isbn = 9780854045280|edition = 1st|chapter = Ingredients for the Modern Perfumery Industry|first = Charles S.|last = Sell}} These were the first natural products shown to have rings with more than six atoms, and at the time that Ružička inferred that civetone as having a 17-member ring.{{cite journal|first = Leopold|last = Ružička|title = Zur Kenntnis des Kohlenstoffringes I. Über die Konstitution des Zibetons|year = 1926|journal = Helv. Chim. Acta|language = de|volume = 9|issue = 1|pages = 230–248|doi = 10.1002/hlca.19260090129}} Synthetic techniques at the time were only known for rings of up to eight members.{{cite book|title = Organic Chemistry – Reactions and Reagents|chapter = Alicyclic Compounds (Sections 7.11 to 7.13)|pages = 237–246|chapter-url = https://books.google.com/books?id=dyxob45rYkkC&pg=PA237|first = O. P.|last = Agrawal|publisher = Krishna Prakashan Media|year = 2009|edition = 46th|isbn = 9788187224655}} Muscone had been isolated in 1904{{cite book|title = The Chemistry of Fragrances: From Perfumer to Consumer|editor-first = Charles S.|editor-last = Sell|pages = 3–23|chapter-url = https://books.google.com/books?id=G90hcKHwrqEC&pg=PA22|publisher = Royal Society of Chemistry Publishing|year = 2006|isbn = 9780854048243|edition = 2nd|chapter = The History of Aroma Chemistry and Perfume|first = David H.|last = Pybus}} but was not identified as 3-methylcyclopentadecanone{{cite journal|first = Leopold|last = Ružička|title = Zur Kenntnis des Kohlenstoffringes VII. Über die Konstitution des Muscons|year = 1926|journal = Helv. Chim. Acta|language = de|volume = 9|issue = 1|pages = 715–729|doi = 10.1002/hlca.19260090197}} until Ružička suspected a macrocycle, having characterised civetone. He also developed a method for synthesising macrocycles, now known as the Ružička large ring synthesis,{{cite journal|title = Zur Kenntnis des Kohlenstoffringes II. Synthese der carbocyclischen Ketone vom Zehner- bis zum Achtzehnerring|first1 = L.|last1 = Ružička|first2 = M.|last2 = Stoll|first3 = H.|last3 = Schinz|journal = Helv. Chim. Acta|year = 1926|volume = 9|issue = 1|pages = 249–264|doi = 10.1002/hlca.19260090130}} which he demonstrated by preparing civetone in 1927.{{cite journal|first1 = L.|last1 = Ružička|first2 = H.|last2 = Schinz|first3 = C. F.|last3 = Seidel|title = Zur Kenntnis des Kohlenstoffringes IX. Über den Abbau von Zibeton, Zibetol und Zibetan|year = 1927|journal = Helv. Chim. Acta|language = de|volume = 10|issue = 1|pages = 695–706|doi = 10.1002/hlca.19270100188}}

File:Rodna_kuća_Lavoslava_Ružičke_01.jpg, Croatia]]

In 1921, the Geneva perfume manufacturers Chuit & Naef asked him to collaborate. Working here, Ružička achieved financial independence, but not as big as he had planned, so he left Zürich to start working for the Basel-based CIBA.{{citation needed|date=March 2021}} In 1927, he took over the organic chemistry chair at Utrecht University in the Netherlands. In the Netherlands, he remained for three years and then returned to Switzerland, which was superior in its chemical industry. A synergistic upheaval in both the administration and chemistry departments coincided to make his good fortune.

Ružička was the first to synthesize musk at an industrial scale. Firmenech named this product Exaltone. Other Swiss manufacturers and DuPont were in competition with them.{{cite journal |last1=Shyndriayeva |first1=Galina |title=Perfume at the Forefront of Macrocyclic Compound Research: From Switzerland to Du Pont |journal=International Workshop on the History of Chemistry |date=2015 |location=Tokyo |url=http://kagakushi.org/iwhc2015/papers/23.ShyndriayevaGalina.pdf}}

In 1934, Ružička synthesized the male hormone androsterone and also proved "its constitutional and configurational relation to the sterols." This was followed in 1935 by the partial synthesis of the much more active male hormone testosterone. Both discoveries led to the pre-eminence of the Swiss industry in the steroid hormone field. At ETH Zurich he became a professor of organic chemistry and started the most brilliant period of his professional career. He widened the area of his research, adding to it the chemistry of higher terpenes and steroids. After the successful synthesis in 1935 of sex hormones (androsterone and testosterone), his laboratory became the world centre of organic chemistry.{{cite journal |doi=10.1530/EJE-19-0071|title=ENDOCRINE HISTORY: The history of discovery, synthesis and development of testosterone for clinical use|year=2019|last1=Nieschlag|first1=Eberhard|last2=Nieschlag|first2=Susan|journal=European Journal of Endocrinology|volume=180|issue=6|pages=R201–R212|pmid=30959485|doi-access=free}} He was awarded in 1936 an honorary degree from Harvard University.

In 1939 he won the Nobel Prize in Chemistry with Adolf Butenandt. Over the period 1934–1939 he published 70 papers in the field of medicinally important steroid sex hormones, and filed several dozen patents besides.

In 1940, following the award, he was invited by the Croatian Chemical Association, where he delivered a lecture to an over-packed hall of dignitaries. The topic of the lecture was From the Dalmatian Insect Powder to Sex Hormones. In 1940 he became a foreign member of the Royal Netherlands Academy of Arts and Sciences,{{cite web|url = http://www.dwc.knaw.nl/biografie/pmknaw/?pagetype=authorDetail&aId=PE00002731|title = Leopold Stephan Ruzicka (1887–1976)|website = KNAW Past Members|publisher = Royal Netherlands Academy of Arts and Sciences|access-date = 4 August 2015|archive-date = 23 September 2015|archive-url = https://web.archive.org/web/20150923232350/http://www.dwc.knaw.nl/biografie/pmknaw/?pagetype=authorDetail&aId=PE00002731|url-status = live}} in 1942 he was elected a foreign member of the Royal Society, and in 1944 he became an international member of the US National Academy of Sciences.{{Cite web|url=http://www.nasonline.org/member-directory/deceased-members/20001250.html|title=Leopold Ruzicka}} During World War II, some of his excellent collaborators were lost, but Ružička restructured his laboratory with new, younger and promising people; among them was young scientist and future Nobel laureate Vladimir Prelog. With new people and ideas new research areas were opened.

File:Grab_Leopold_Ružička.jpg in Zürich, Switzerland]]

In 1946, Ružička and Lardon "established that the fragrance of ambergris is based on the triterpene (named) ambrein".{{cite journal |doi=10.1002/hlca.19460290414|title=Zur Kenntnis der Triterpene. (105. Mitteilung) Über das Ambreïn, einen Bestandteil des grauen Ambra|year=1946|last1=Ruzicka|first1=L.|last2=Lardon|first2=F.|journal=Helvetica Chimica Acta|volume=29|issue=4|pages=912–921}}{{cite journal | last1 = Prelog | first1 = Vladimir | author-link1 = Vladimir Prelog| last2 = Jeger | first2 = Oskar | doi = 10.1098/rsbm.1980.0013 | title = Leopold Ruzicka (13 September 1887 – 26 September 1976) | journal = Biogr. Mem. Fellows R. Soc. | volume = 26 | pages = 411–501 | year = 1980}}

Following 1950, Ružička returned to chemistry, which had entered a new era of research. Now he turned to the field of biochemistry, the problems of evolution and the genesis of life, particularly to the biogenesis of terpenes. In 1953, he published his hypothesis, the Biogenetic Isoprene Rule (that the carbon skeleton of terpenes is composed variously of regularly or irregularly linked isoprene units), which was the peak of his scientific career.{{cite journal |title = The isoprene rule and the biogenesis of terpenic compounds |first = Leopold |last = Ružička|journal = Cellular and Molecular Life Sciences|volume = 9|issue = 10|pages = 357–367 |year = 1953 |doi = 10.1007/BF02167631 |pmid = 13116962 |s2cid = 44195550 }} In 1952, Oskar Jeger and he supervised a team which isolated lanosterol and established the link between terpenes and steroids.Voser, W., M. U. Mijovik, H. Heusser, O. Jeger u. L. Ruzicka: Über die Konstitution des Lanostadienols (Lanosterins) und seine Zugehörigkeit zu den Steroiden. Helv. chim. Acta 35, 2414 (1952). Ružička retired in 1957, turning over the running of the laboratory to Prelog.{{cite journal |pmid=17285778|year=2007|last1=Shampo|first1=M. A.|last2=Kyle|first2=R. A.|last3=Steensma|first3=D. P.|title=Leopold Ruzicka—1939 Nobel Prize in chemistry|journal=Mayo Clinic Proceedings|volume=82|issue=1|pages=1p preceding table of contents}}

Ružička was the recipient of eight honorary doctorates and the 1938 Marcel Benoist Prize. He was listed as an author on 583 scientific papers. In 1965, he became an honorary member of the Polish Chemical Society,{{cite news|url=https://ptchem.pl/pl/honors/president-of-honor-and-honorary-members-of-ptchem |title=President of honour and honorary members of PTChem |access-date=23 February 2020}} and he was an honorary member of the American Academy of Arts and Sciences. After the war he acquired a taste for Dutch masterpieces, which he later lodged in the Kunsthaus Zürich as the Ružička collection. He militated against nuclear weapons.

In 1970, Ružička delivered to the Nobel Laureate Conferences in Lindau a lecture entitled "Nobel Prizes and the chemistry of life".

In later years, he served as a consultant to Sandoz A. G. of Basel.

Ružička dedicated significant efforts to the problems of education. He insisted on a better organization of academic education and scientific work in the new Yugoslavia, and established the Swiss-Yugoslav Society. Ružička became an honorary academician at the then Yugoslav Academy of Sciences and Arts in Zagreb.

In 1974 he was awarded the Order of the Yugoslav Flag with Golden Wreath.

At ETH Zurich, the Ružička Award was established in 1957 on the occasion of his retirement, for young chemists working in Switzerland.

In his native Vukovar, a museum was opened in his honour in 1977.

Ružička's archives are kept at ETH Zurich.{{Cite web|url=https://library.ethz.ch/en/locations-and-media/platforms/short-portraits/ruzicka-leopold-1887-1976.html|title = Leopold Ruzicka (1887–1976)}}

The Ružička reaction is named after him.{{cite journal |title=Zur Kenntnis des Kohlenstoffringes II. Synthese der carbocyclischen Ketone vom Zehner- bis zum Achtzehnerring|author1=L. Ružicka|author2=M. Stoll|author3=H. Schinz|journal=Helvetica Chimica Acta|year=1926|volume=9|issue=1|pages=249–264|doi=10.1002/hlca.19260090130}}

Ružička married twice: to Anna Hausmann in 1912, and in 1951 to Gertrud Acklin. From 1929, he lived at Freudenbergstrasse 101 until the last years of his life. He died in Mammern, Switzerland, a village on Lake Constance at the age of 89.{{cite news |title=Dr. Leopold Ruzicka Dies M Switzerland at Age 89; Won Nobel in Chemistry |url=https://www.nytimes.com/1976/09/27/archives/dr-leopold-ruzicka-dies-in-switzerland-at-age-89-won-nobel-in.html |work=New York Times |date=27 September 1976}}

{{reflist}}

{{Commons category}}

• Speich, Daniel. [http://www.ethistory.ethz.ch/besichtigungen/touren/vitrinen/konjunkturkurven/vitrine61 "Leopold Ruzicka und das Verhältnis von Wissenschaft und Wirtschaft in der Chemie"] {{in lang|de}}. ETH Zürich. Retrieved 14 August 2017.
• {{Nobelprize}} including the Nobel Lecture on 12 December 1945 Multimembered Rings, Higher Terpene Compounds and Male Sex Hormones

{{Croatian Nobel Laureates}}

{{Nobel Prize in Chemistry Laureates 1926-1950}}

{{1939 Nobel Prize winners}}

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