New labdane diterpene glycosides from Amphiachyris amoena

Five new labdane diterpene glycosides, amoenolide A 19-beta-D-glucopyranoside [1], and amoenolides E [3], F [4], G [6], and H [8] were isolated from the above-ground parts of Amphiachyris amoena. Amoenolide F is a 19-beta-D-glucopyranoside, while the others are 6-alpha-L-arabinopyranosides. Their structures were established by chemical and spectral methods, especially high-field nmr techniques, and complete 1H- and 13C-nmr assignments are given.