Two Novel Triterpenoids from Dysoxylum hainanense

Two novel rearranged oleanane-type triterpenes, dysoxyhainanin A (1) possessing a unique 1,3-cyclo-2,3-seco A ring with a formamido-containing appendage and dysoxyhainanin B (2) featuring an unprecedented 1,2-dinor-3,10:9,10-bisseco skeleton, were isolated from Dysoxylum hainanense. Dysoxyhainanin A (1) exhibited significant antibacterial activity against Gram-positive bacteria.