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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
The Carotene Kid
21 April 1999 4:00 pm
Paul Karrer, a Swiss organic chemist famous for his work with vitamins and natural dyes, was born on this day in 1889.
Karrer studied the chemistry of plant pigments, including anthocyanins, xanthophylls, and carotenoids. He showed that carotene--the yellow, orange, or red color in fruits and vegetables--came in two forms and that one of them, beta-carotene, was a precursor to vitamin A.
By 1930, Karrer had worked out the chemical structures of carotene and vitamin A, which he finally succeeded in synthesizing in 1950. Karrer also solved the structures of vitamin B-2 (riboflavin), vitamin E (alpha-tocopherol), and vitamin B-12. For these achievements he shared the 1937 Nobel Prize in chemistry. Karrer's organic chemistry textbook, Lehrbuch der Organischen Chemie, published in 1930 and translated into five languages, became a standard reference book for several generations of chemists.