Synthesis, antileukemic activity, and predicted ABL kinase binding dynamics of novel oleanolic acid derivatives in...

Chronic myeloid leukemia (CML) is a hematological malignancy driven by the BCR::ABL fusion protein. Although tyrosine kinase inhibitors such as imatinib have markedly improved clinical outcomes, treatment resistance remains a major challenge. Natural product-derived compounds may offer alternative therapeutic opportunities. This study investigated the antiproliferative and pro-apoptotic effects of newly synthesized oleanolic acid (OA) derivatives in K562 cells and evaluated their predicted interactions with the ABL kinase domain. OA derivatives were synthesized and characterized by FT-IR and NMR. Cytotoxicity was assessed using the WST-8 assay. Apoptosis, mitochondrial membrane potential, and cell-cycle distribution were analyzed by flow cytometry. Expression levels of BCL2, BAX, Caspase-3, Caspase-8, and Caspase-9 were determined by qPCR, whereas BCR::ABL protein levels were assessed by Western blotting. Boltz-2 complex prediction, molecular dynamics simulations, and MM/PBSA calculations were used to evaluate predicted binding stability, interaction patterns, and energetics. OA-Acid showed the lowest IC₅₀, whereas OACN showed the highest value . Apoptosis was highest in imatinib- and OACN-treated cells, and mitochondrial membrane potential decreased significantly in both groups. OA-Acid and MCM35 produced the greatest G0/G1 accumulation. Apoptosis-related gene expression was altered in a compound-dependent manner. OA-Acid showed the greatest decrease in BCR::ABL protein level. Computational analyses supported conformationally stable predicted interactions of OA, OA-Acid, and OACN within the ABL ATP-binding region. OA derivatives produced distinct cytotoxic, apoptotic, mitochondrial, cell-cycle, and molecular effects in K562 cells. Computational findings supported predicted interactions within the ABL kinase domain, warranting further chemical and mechanistic evaluation.