Quantitative structure-cytotoxicity relationship analysis of betulinic acid and its derivatives by semi-empirical molecular-orbital method.

A semi-empirical molecular-orbital method (CAChe) demonstrates that the cytotoxicity of betulinic acid derivatives can be predicted by several physical parameters (such as heat of formation, hydrophobicity (log P), watersolubility, ionization potential, electron affinity, dipole moment), but not by molecular size (maximum length and width). The present study demonstrates how this method can be applied to estimate the cytotoxic activity of structurally-related compounds.