IRIDOID GLUCOSIDES AS SOURCES OF CYCLOPENTANOID 1,5-DIALDEHYDES: CONVERSION OF AUCUBIGENIN TO EUCOMMIAL AND EUCOMMIOL

Article abstract of DOI:10.1016/S0031-9422(00)81832-4

Key Word Index - Eucommia ulmoides; Eucommiaceae; aucubin; aucubigenin; iridoid aglycones; eucommial; eucommiol; 1H NMR and 13C NMR.Aucubigenin, which exists only in the closed hemiacetal form, has been transformed into a stable conjugated 1,5-dialdehyde form, 'eucommial', by a base-catalysed Δ⁷ -> Δ⁸ double-bond shift.Further reduction of eucommial leads to eucommiol, which co-occurs with aucubin in the autumn in Eucommia ulmoides and Aucuba japonica.The successful transformation of aucubin to eucommiol seems to support an in vivo relationship between these compounds.