A quantum chemical and statistical study of ganoderic acids with cytotoxicity against tumor cell.

A set of molecular properties (variables) of 24 ganoderic acids with cytotoxicities against Meth-A tumor cells was calculated by the molecular orbital semi-empirical method AM1 and ChemPropStd. Pattern recognition techniques, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to reduce dimensionality and investigate which subset of variables could be more effective for classifying the ganoderic acids according to their degree of cytotoxicities against tumor cells. The PCA and HCA studies showed that EHOMO (highest occupied molecular orbital energy), Mulliken electronegativity (chi), electronic energy (Eel), log P (octanol/water partition coefficient), and Connolly molecular area (MA) are the most important variables for the classification between the ganoderic acids with higher and lower cytotoxicities against tumor cells.