Lanostanoid Triterpenes from Laetiporus sulphureus and Apoptosis Induction on HL-60 Human Myeloid Leukemia Cells

A new lanostanoid triterpene, 3-oxosulfurenic acid (1), together with three known triterpenes (3, 4, and 7) were isolated from the fruit bodies of Laetiporus sulphureus. Cytotoxicity of these compounds and their derivatives (2, 5, and 6) was evaluated on HL-60 cells. Further studies revealed that acetyl eburicoic acid (5) was the most potent apoptosis inducer. Apoptosis was accompanied by both the activation of caspase-3 and the fragmentation of poly(ADP-ribose) polymerase-1 and was also associated with an early release of cytochrome c from the mitochondria.