The flowers of A. amplexicaulis afforded, in addition to xanthalongin ( 1), 11beta,13-dihydroxanthalongin (2), its 11-epimer (3), and 11alpha,13-dihydro-4H-xanthalongin (4), the new xanthanolide glycosides 11alpha, 13-dihydro-4 H-xanthalongin 4- O-beta-D-glucopyranoside (5) and its 11-epimer (6). The glycosides were also isolated from the flowers of A. mollis. The structures were elucidated by NMR spectroscopy (1)H-NMR, COSY, (13)C-NMR, HETCOR, DEPT), MS (EI, FAB, FD), and enzymatic hydrolysis of the glycosides. The chemo-taxonomic importance is discussed.