ChemInform Abstract: New Cardenolide Glycosides from the Defence Glands of Chrysolinina Beetles (Coleoptera : Chrysomelidae)

The composition of the defence secretions of six species of chrysomelid beetles (Chrysolina polita, C. americana, C. grossa, C. herbacea, C. fastuosa, and Oreina gloriosa) belonging to the sub-tribe Chrysolinina has been investigated. Two known cardenolide aglycones, sarmentogenin (1) and oleandrigenin (23), and fourteen new cardiac glycosides (7–20) have been isolated and their structure established by spectral and chemical methods. Three of the glycosides (18, 19, and 20) are based on a new cardenolide aglycone, namely Δ11-digitoxigenin. All the new glycosides but 17 contain monosaccharides (e. g. lyxose, ribose, allose) which are rarely encountered in secondary metabolites. Ethanolamine was shown to be present in the secretions of the six species examined, as well as in C. hyperici and in C. coerulans. In the latter, ethanolamine is accompanied by its N-(γ-glutamyl) derivative.