... Ver-sion 2.0). In addition, these GC-MS analyses (data notshown) revealed the formation of the known plantCCD1 mono-oxo products 6-methyl-5-hepten-2-one,3-OH-b-ionone and pseudoionone, the ... converted into3-OH-b-ionone (1) and apo-10,10¢-carotendial (C14, 2). The products3-OH-b-ionone (C13, 1), apo-10,10¢-carotendial (C14dialdehyde, 2),pseudoionone (C13, 3), apo-8,10¢-carotendial ... preference of OsCCD1 for the C5¢–C6¢ and C7¢–C8¢ double bonds depends on the nature of the substrate. The cleavage of a sole double bond in the cyclic moi-ety of 3-OH-c-carotene and of monocyclic b-apocarote-nals...