Exerting DNA Damaging Effects of the Ilimaquinones through the Active Hydroquinone Species

Possessing the quinone moiety, ilimaquinone (1), a sponge–derived sesquiterpene quinone, has been hypothesised to express its cytotoxicity through redox cycling process, yielding active product(s) that can cause DNA damage. To determine damaging effects of 1 and examine whether transformation may participate in functions, properties 1, corresponding hydroquinone (2) triacetates (3) their 5-epimeric counterparts (4–6) were tested compared. When incubated directly with plasmid DNA, hydroquinones only species capable cleaving DNA. In cell-based assays, however, quinones same range as hydroquinones, all damaged cellular similar manner. The situ reduction 4 supported by decreases when cells pre-exposed dicoumarol, an NAD(P)H:quinone oxidoreductase (NQO1) inhibitor. results confirmed activities ilimaquinones 4, indicated necessity undergo in-situ into thereby exerting parts cytotoxic mechanisms.