Natural α,β-amyrins were isolated from endemic Brazilian Esenbeckia grandiflora Mart., and eight synthetic derivatives were obtained by esterification reactions with bromo acetate, followed by amine treatment. The structures of the all compounds were confirmed by 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and high-resolution mass spectrometry (HRMS) data analysis. The derivatives were screened for cytotoxic activity against human tumor cell-lines PC3 (prostate carcinoma), HCT-116 (colon carcinoma) and HL60 (leukemia). HCT-116 and PC3 cell-lines showed weak tumor growth inhibition (range of 13.9-25.4 and 10.3-28.8%, respectively), but the derivatives presented moderate activity against HL60 (range of 13.6-59.0%). Diethyl, aniline, morpholine and imidazole moieties presented higher activities (range of 45.9-59.0%).
Keywords:
α,β-amyrins; pentacyclic triterpenes; Esenbeckia grandiflora; aminoester derivatives; antiproliferative evaluation
