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Medical Term:


Pronunciation: i'o-non


One of two cyclic terpene ketones with an odor of violets or cedar wood, the a and ß varieties of which differ in the location of the double bond in the ring: provitamins A and vitamin A have ionone configuration in the ring portion; a-carotene contains one a- and one ß-ionone moieties, ß-carotene contains two ß-ionone moieties, and ?-carotene contains one ß-ionone moiety.

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