Naphthazarin derivatives (VII): Antitumor action against ICR mise bearing ascitic S-180 cells

Various analogues of 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) such as 2- or 6-(1-hydroxyiminoalkyl)-DMNQs were prepared and evaluated for the antitumor action. (1-Hydroxyiminoalkyl)-DMNQ derivatives expressed greater antitumor action than (1-hydroxyalkyl)- or acyl-DMNQ derivatives. Moreover 6-(1-hydr oxyiminoalkyl)-DMNQ derivatives expressed higher antitumor action than 2-su dstituted ones, suggestive of a steric effect. Some of 6-(1-propyloxyalkyl) -DMNQ derivatives with an alkyl group of butyl to octyl moiety showed T/C v alues of > 400%.