Apotirucallane Triterpenes from Dysoxylum roseum

Chemical investigation of the biologically active compounds in Dysoxylum roseum leaves has led to the isolation and characterization of five new apotirucallane-derived triterpenes, dysorones A [1], B [2], C [3], D [4], and E [5], and beta-sitosterol. The major compound, dysorone E [5], exhibits moderate cytotoxic activity in vitro against the growth of KB human buccal carcinoma cells (ED50 3.5-mu-g/ml).