Two novel 18,19-seco-ursane triterpenoid saponins, ilexasprellanosides J-K (1-2, resp.), 3-O-α-l-Rhamnopyranosyl-(1 → 2)-β-d-xylopyrannosyl-19-O-β-d-glucopyranosyl-16-β-hydroxyl-18,19-seco-13(18)-urs-ene-21, 28-lactone (1), 3-O-β-d-Xylopyrannosyl-19-O-α-l-rhamnopyran osyl-(1 →