Antitumor activity of asterriquinones from Aspergillus fungi. IV. An attempt to modify the structure of asterriquinones to increase the activity.

An attempt was made to obtain more potent antitumor compounds by chemically modifying asterriquinones. Amino-and aziridinyl-asterriquinone were newly synthesized, but showed no activity. However, dimethylallylation of asterriquinone Cl, which had no effect in vivo, yielded an active compound, with a change in pKa value from 5.0 to 7.2. This suggests that other active compounds may be obtained by the chemical modification of asterriquinones with various other functional groups.