6-(1-Alkenoyloxyalkyl)-5,8-dimethoxy-1,4-naphthoquinone derivatives: Synthesis and evaluation of antitumor activity

Thirty six 5,8-dimethoxy-1,4-naphthoquinone derivatives, which bear unsaturated alkyl side chain with ester bond, were synthesized and tested cytotoxic activity on L1210 cells and antitumor activity against ICR mice bearing S-180 cells. It could be recognized that the cytotoxicities of naphthoquinones with R₁ being methyl and propyl (IV1∼24) were not enhanced by replacing the alkanoyls with alkenoyls. In contrast, the introduction of the alkenoyl moieties on the compounds with R₁=hexyl (IV25∼36) resulted in the enhancement of their cytotoxicities. Replacement of alkanoyl group with an alkenoyl group generally increased the T/C value of the mice bearing S-180 cells.