The exudates of Hypochoeris radicata leaves stressed with cupric chlor
ide afforded two eudesmane- and guaiane-type sesquiterpenes, and two a
lkenals, (2E,4E)-6-hydroxyhexadienal and (2E,4E)-hexadienedial (mucond
ialdehyde). Their structures were determined by spectroscopic and synt
hetic methods.