Synthesis and evaluation of nitrogen-containing derivatives of 3,11-dioxo-olean-12-en-30-oic acid against HIV-1 protease

Thirteen nitrogen-containing derivatives of 3,11-dioxo-olean-12-en-30-oic acid were synthesised by introducing various amino acids and nitrogen-containing heterocyclic groups at the 30-carboxyl group, starting from 18 beta-glycyrrhetinic acid. Among the 13 derivatives, 10 exhibited inhibitory activity against HIV-1 PR, with IC50 values ranging from 0.19 to 0.94 mM. Notably, derivatives 2, 3 and 5 displayed relatively moderate inhibitory activity, with IC50 values below 0.24 mM. Molecular docking studies provided further insights into the interaction between derivatives (2, 3 and 5) and the active sites of HIV-1 PR. The results revealed favourable hydrophobic-hydrophobic and hydrogen bonding interactions, with docking scores ranging from -6.22 to -7.00 and glide emodel values from -62.9 to -48.6 (kcal/mol). These findings underscore the potential of derivatives 2, 3 and 5 as promising candidates for the development of HIV-1 PR inhibitors.