紫罗兰酮（Ionone）是一种萜类物质，根据双键位置不同有三种异构体。 紫罗兰酮属于玫瑰酮，存在于包括玫瑰精油的多种花精油中。β-紫罗兰酮是玫瑰香气的主要贡献物，虽然其在精油中含量相对较低。紫罗兰酮是一个重要的香料化学品，用于香水，香料和调味料。紫罗兰酮在生物中来源于类胡萝卜素的降解。

胡萝卜素包括α-胡萝卜素，β-胡萝卜素，γ-胡萝卜素，叶黄素和β-隐黄质，都含有β-紫罗兰酮结构，具有维生素A的活性，它们在动物体内可转化成视黄醇。无β-紫罗兰酮结构的类胡萝卜素则不能被转换为视黄醇，没有维生素A活性。

The ionones 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.