New secoiridoid glycosides from the buds of Lonicera macranthoides.

Two new secoiridoid glycosides, named ethyl secologanoside (1) and 6'-O-alpha-L-arabinopyranosyl demethylsecologanol (2), together with three known ones, secologanoside (3), secoxyloganin (4), and loniceroside (5), were isolated from the dried buds of Lonicera macranthoides. The structures of the new compounds were determined on the basis of detailed spectroscopic analyses and acidic hydrolysis.