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A series of triterpenoid pyrones was synthesized and subsequently modified to introduce phthalimide or phthalate moieties into the triterpenoid skeleton. These compounds underwent in vitro cytotoxicity screening, revealing that a subset of six compounds exhibited potent activity, with IC 50 values in the low micromolar range. Further biological evaluations, including Annexin V and propidium iodide staining experiment revealed, that all compounds induce selective apoptosis in cancer cells. Measurements of mitochondrial potential, cell cycle analysis, and the expression of pro- and anti-apoptotic proteins confirmed, that apoptosis was mediated via the mitochondrial pathway. These findings were further supported by cell cycle modulation and DNA/RNA synthesis studies, which indicated a significant increase in cell accumulation in the G0/G1 phase and a marked reduction in S-phase cells, alongside a substantial inhibition of DNA synthesis. The activation of caspase-3 and the cleavage of PARP, coupled with a decrease in the expression of Bcl-2 and Bcl-XL proteins, underscored the induction of apoptosis through the mitochondrial pathway. Given their high activity and pronounced effect on mitochondria function, trifluoromethyl pyrones 1f and 2f , and dihydrophthalimide 2h have been selected for further development. [Display omitted] • A set of novel triterpenoid pyrones, phthalimides and phthalates was synthesized. • Six compounds with high in vitro cytotoxicity in CCRF-CEM cells was identified. • All compounds induce apoptosis via the mitochondrial intrinsic pathway. • Pyrones 1f , 2f , and dihydrophthalimide 2h were selected for further development. [ABSTRACT FROM AUTHOR]

A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22 , 4.30 , 4.33 , 4.39 had IC 50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC 50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC 50 and almost complete inhibition at 5 × IC 50. Interestingly, compound 4.39 at 5 × IC 50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39 , therefore 4.22 was the finally selected candidate for the development of anticancer drug. [Display omitted] • Forty new triterpenoids were prepared from 30-oxobetulinic acid by Wittig reaction • Four compounds had high selective cytotoxicity to cancer cells • Compounds 4.22 and 4.39 were selected for further development • Both compounds cause selective apoptosis in cancer cells via the intrinsic pathway • Diene 4.22 has appropriate pharmacological parameters and will be further developed [ABSTRACT FROM AUTHOR]