Ionone
The ionones, from greek ἴον ion "violet", are a series of closely related chemical substances that are part of a group of compounds known as rose ketones, which also includes damascones and damascenones. Ionones are aroma compounds found in a variety of essential oils, including rose oil. β-Ionone is a significant contributor to the aroma of roses, despite its relatively low concentration, and is an important fragrance chemical used in perfumery. The ionones are derived from the degradation of carotenoids.
alpha-ionone | |||
beta-ionone | |||
gamma-ionone | |||
Names | |||
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IUPAC names
α: (3E)-4-(2,6,6-Trimethylcyclohex-2-en-1-yl)but-3-en-2-one β: (3E)-4-(2,6,6-Trimethylcyclohex-1-en-1-yl)but-3-en-2-one γ: (3E)-4-(2,2-Dimethyl-6-methylenecyclohexyl)but-3-en-2-one | |||
Other names
Cyclocitrylideneacetone, irisone, jonon | |||
Identifiers | |||
3D model (JSmol) |
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ChEBI | |||
ChemSpider | |||
PubChem CID |
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UNII | |||
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Properties | |||
C13H20O | |||
Molar mass | 192.30 g/mol | ||
Density | α: 0.933 g/cm3 β: 0.945 g/cm3 | ||
Melting point | β: −49 °C (−56 °F; 224 K) | ||
Boiling point | β: 126 to 128 °C (259 to 262 °F; 399 to 401 K) at 12 mmHg | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
The combination of α-ionone and β-ionone is characteristic of the scent of violets and used with other components in perfumery and flavouring to recreate their scent.
The carotenes α-carotene, β-carotene, γ-carotene, and the xanthophyll β-cryptoxanthin, can all be metabolized to β-ionone, and thus have vitamin A activity because they can be converted by plant-eating animals to retinol and retinal. Carotenoids that do not contain the β-ionone moiety cannot be converted to retinol, and thus have no vitamin A activity.