Paul Karrer conducts research on plant pigments and vitamins. He illuminates the chemical structure of the carotenoids, which is necessary for the correct formula of beta-carotene. This work enables the synthesis of vitamin A and establishes the structure of a vitamin or provitamin for the first time (1931). In addition Paul Karrer synthesizes vitamin B2, vitamin E (1938) and vitamin K (1939).

Paul Karrer becomes an assistant in the Chemical Institute of the University of Zurich for one year.

After returning to Switzerland in 1892, Paul Karrer attends school at Wildegg and grammar school in Lenzburg, Aarau.

Paul Karrer is born to his parents Paul Karrer and Julie Lerch, both Swiss, in Moscow, Russia.

After publishing more than 1,000 papers about organic chemistry and the famous textbook 'Lehrbuch der Organischen Chemie' (1927), Paul Karrer dies on 18. June 1971.

Paul Karrer and Helena Froelich get married in 1914. They have three sons, Ehrlich, Heinz and Jurg.

After returning to Zurich, Paul Karrer becomes Professor of Chemistry and Director of the Chemical Institute at the University of Zurich.

Paul Karrer works as an assistant at the Institute for Experimental Therapy at Frankfurt am Main, where he does researches on the synthesis of organic arsenic compounds.

Paul Karrer is awarded the 1937 Nobel Prize in Chemistry together with Walter Norman Haworth for his investigations on carotenoids, flavins and vitamins A and B2.

After studying Chemistry at the University of Zurich, Paul Karrer gains his PhD in 1911.