The eureka moment

In 1930, Szent-Györgyi returned to Hungary, accepting a post as professor of medicinal chemistry at the University of Szeged. There he showed his sample of hexuronic acid to J. L. Svirbely, an American-born chemist of Hungarian descent, who had previously worked with Charles King, a vitamin researcher at the University of Pittsburgh. Svirbely, working with Szent-Györgyi, conducted a landmark experiment on guinea pigs, which, like humans, must ingest vitamin C to maintain health since it cannot be produced within their bodies.

Svirbely divided the animals into two groups: one that received boiled food (boiling destroys vitamin C) and the other that was fed food enriched with hexuronic acid. The latter group flourished, while the first aggregation of guinea pigs developed scurvy-like symptoms and died. Svirbely and Szent-Györgyi decided hexuronic acid - renamed ascorbic acid to reflect its anti-scurvy properties - was indeed the long sought vitamin C. In 1933, Szent-Györgyi set about to find additional, natural sources of ascorbic acid for further study.

Although orange juice and lemon juice have high levels of ascorbic acid, they contain sugars that make purification extremely difficult. Szent-Györgyi solved the problem by making imaginative use of the local specialty, paprika. Szeged is the paprika capital of the world, where matching salt and paprika shakers are found on every restaurant table. One night, Szent-Györgyi recalled, his wife served him fresh red paprika for supper. As he wrote in his autobiography, "I did not feel like eating it so I thought of a way out. Suddenly it occurred to me that this is the one plant I had never tested. I took it to the laboratory ... [and by] about midnight I knew that it was a treasure chest full of vitamin C."

Within several weeks Szent-Györgyi had produced three pounds of pure crystalline ascorbic acid, enough to show — when fed to the vitamin C-deficient guinea pigs — that the acid was equivalent to vitamin C.

Discovery of vitamin C | Malnutrition and death | Suspected but elusive | The eureka moment | Nobel and beyond | Landmark designation

Copyright ©2007 American Chemical Society. All Rights Reserved. 1155 16th Street NW, Washington DC 20036
202-872-4600, 800-227-5558