Synthesis and cytotoxicity of triterpenoids derived from betulin and betulinic acid via click chemistry

In this study, a series of triazole substituted betulin and betulinic acid derivatives was designed and synthesized via click chemistry at C-30 position. Eighteen target compounds were evaluated in vitro for their antitumor activities against leukemia cell-line HL-60. Seventeen compounds have not reported before. The cytotoxic experiment showed that most of betulinic acid derived triazoles have higher cytotoxic profile than betulinic acid. Among them, compound 30-[4-(4-fluorophenyl)-1H-1,2,3-triazol-1-yl] betulinic acid (7b) showed the best IC50 value (1.3 μM) against leukemia cell-line HL-60 (eight- to ninefold higher potency than betulinic acid).