Two Novel Triterpenoids with Antiproliferative and Apoptotic Activities in Human Leukemia Cells Isolated from the Resin of Garcinia hanburyi

Two new triterpenoids, 2α-hydroxy-3β- O-acetyllup-20(29)-en-28-oic acid ( 1) and 3- O-(4′- O-acetyl)-α- L-arabinopyranosyloleanolic acid ( 2), together with two known triterpenoids, betulinic acid ( 3) and messagenic acid ( 4) were isolated from the CHCl 3 extract of GARCINIA HANBURYI resin. The structures were elucidated by analysis of the NMR spectroscopic data. The antiproliferative effects and the apoptosis induction abilities of compounds 1 and 2 were determined in four human leukemia cell lines. Compound 2 was more potent than compound 1 in inhibiting cell growth with IC 50 values of 2.45, 2.69, 2.42, and 4.15 μM in HL-60, NB4, U937 and K562 cells, respectively.