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Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
- 6 March 2014 1:04 pm , Vol. 343 , #6175
- 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.