Stereochemistry of an alcohol oxidase from the defensive secretion of larvae of the leaf beetle Phaedon armoraciae (Coleoptera: Chrysomelidae)

Article abstract of DOI:10.1016/0040-4020(96)00298-0

Larvae of the leaf beetle Phaedon armoraciae produce the iridoids chrysomelidial 1 and plagiodial 3 from geraniol 6 by an oxidative sequence identical to that known in plants. Following ω-oxidation of geraniol the resulting 8-hydroxygeraniol 7 is oxidised via 8-oxogeraniol 14 and 8-hydroxygeranial 15 and to the dialdehyde 8. In plants this transformation is achieved by NADP⁺ dependent oxidoreductases. However, in the defensive secretion of several leaf beetles an oxygen-dependent oxidase is present. The enzyme catalyses the removal of the C(1)- and C(8)-H(R) hydrogen atoms (Re-specificity) from the diol 7 yielding 8-oxogeranial 8.