A theoretical investigation of cytotoxic activity of celastroid triterpenoids.

Quantum chemical calculations at the B3LYP/6-31G* level of theory have been carried out on 20 celastroid triterpenoids to obtain a set of molecular electronic properties and to correlate these with cytotoxic activities. The cytotoxic activities of these compounds can be roughly correlated with electronic effects related to nucleophilic addition to C6 of the compounds: the energies of the frontier molecular orbitals (E(HOMO) and E(LUMO)), the HOMO-LUMO energy gap, the dipole moment, the charge on C6, and the electrophilicity on C6.