Synthesis and cytotoxicity of new oleanonic acid derivatives bearing pyridine substituent at positions C(2) and C(28)

New oleanonic acid derivatives bearing the pyridine moieties at the positions C(2) and C(28) were synthesized. Heterocyclic moieties were introduced in position C(2) of oleanonic acid by aldol condensation, and in position C(28) by N-acylation. Cytotoxicity of the synthesized compounds was evaluated against 12 tumor cell lines. Aminopyridine-derived oleanonic acid amides with 3- and 4-pyridinylmethylidene group were found to be active against a human prostate cancer cell line PC3 with half maximal inhibitory concentration (IC50) values equal to 1.20 and 2.06 µmol L−1, respectively. © 2024 Elsevier B.V., All rights reserved.