8013-90-9

Light-yellow to colorless liquid; violet odor.Soluble in alcohol, ether, mineral oil, and propylene glycol; insoluble in water and glycerol.

The α-isomer has been reported in the essential oil of Sphaeranthus inducus L. and in the absolute essence of Acacia farnesiana. The ?-isomer has been reported to be found in raspberry, in the distillate from flowers of Boronia megatisma Nees., and in a few other essences (Fenaroli's Handbook of Flavor Ingredients, 1971). α-Ionone occurs in the essential oils of orange and Ligusticum elatum, in extract of Osmanthus fragrans Lour., in the flavour of tea, and in the essential oil of tangelo (Citrus reticulata Blanco χ C paradisi MacFayden). ?-Ionone is an important constituent of essential oils of Cunila lythrifolia Benth., and Siparuna nicaraguensis Heml. ; it has also been found in tomatoes

By chemical synthesis or by condensing citral with acetone to form pseudo-ionone which is then cyclized by acid-type reagents (Bedoukian, 1967).

Ionones are metabolized mainly by oxidation of the ring system at the carbon atom alpha to the ring double bond and by reduction of the carbonyl group (Williams, 1959). On administration to dogs α-ionone is hydroxylated in the ring at the carbon atom which is alpha to the ring double bond to yield 5-hydroxy-a-ionone (Prelog, Wursch & Meier. 1951). Rabbits dosed orally with /Monone excreted in the urine unchanged ?-ionone, 3-oxo-?-ionone, 3-oxo-?- ionol, dihydro-3-oxo-?-ionol and 3-hydroxy-?-ionol. Excretion products were isolated as 2,4-dinitrophenyl: hydrazone derivatives and as p-nitrobenzoate derivatives. The glucuronides of 3-oxo-?-ionol and dihydro-3- oxo-j?-ionol were also detected in the urine