Quantum chemical study for genotoxic and antitumor activities of hydroxyanthraquinones

For anthraquinone and its mono- and dihydroxyl derivatives, and for their semiquinone anion radicals, semiempirical MNDO (moderately neglected differential overlap)/H calculations were performed and an attempt was made to correlate the calculated quantum quantities with the genotoxic and the antitumor activities. From these calculations, it was found that the electrophilic frontier electron densities (fE beta) on the beta position in anthraquinones were distinctly correlated with the genotoxic activity. On the other hand, calculations for the semiquinone anion radicals revealed the great stabilizations by the intramolecular hydrogen bond of the carbonyl group with alpha-hydroxyl groups. It has been suggested that this type of stabilization may be associated with the antitumor activity of several hydroxylanthraquinone derivatives.