The synthesis and cytotoxicity evaluation of a series of β-boswellic acid-amino acid conjugates have been described to enhance anti-cancer efficacy, with a focus on KRASG13D-mutant colorectal cancer (CRC) cells. Among these, compound 8b, which incorporates a hydrophilic urea linker, demonstrated significantly improved aqueous solubility, cellular uptake, and cytotoxicity. In vitro, 8b showed potent activity with IC50 values of 1.95 ± 0.71 μM (HCT-116G13D) and 2.16 ± 1.06 μM (HCT-15G13D), compared with β-boswellic acid (IC50 > 25 μM). Compound 8b induced G1-phase arrest, oncogene-induced senescence, and mitochondrial membrane depolarization in both cell lines. Mechanistic studies revealed selective inhibition of CDK6 (IC50 = 703 nM) and downregulation of TWIST1, key mediators of tumor progression and drug resistance. Molecular docking and MD simulations confirmed strong and stable interactions with CDK6 and KRASG13D proteins. In vivo, 8b exhibited significant tumor growth inhibition in multiple murine models (up to 89.58 % TGI in EAC) with minimal systemic toxicity and favorable pharmacokinetic parameters.
