Triterpenoid saponins from Gouania lupuloides

The stems of Jamaican chawstick, Gouania lupuloides, have yielded two novel 16,17-seco-dammaranoid saponins, designated gouanoside A [4] and gouanoside B [5]. Structural assignments are based on spectroscopic data including 2D nmr experiments on the corresponding aglycones, gouanogenin A [1] and gouanogenin B [3].