BIOPHYSICAL AND BIOLOGICAL PROPERTIES OF NEWLY SYNTHESIZED DIOXINOCOUMARIN DERIVATIVES .1. DARK EFFECTS ON T7 PHAGE AND HELA-CELLS

Several dioxinocoumarin derivatives have been synthesized for photoche motherapeutical purposes. The physicochemical properties of 3,4-benzo- 6,7-dioxinocoumarin and its biological activity in the dark were studi ed with regard to future photobiological applications. It was found th at molecular aggregates are formed in aqueous solution at a concentrat ion higher than 10(-5) mol l-1. In the dark, 3,4-benzo-6,7-dioxinocoum arin inactivates T7 phage and inhibits the growth of HeLa cells in a c oncentration-dependent manner. The dark inactivation of T7 phage was q uantitatively characterized. It was found to be higher than that of 8- methoxypsoralen (8-MOP) and approximately equal to 4,6,4'-trimethylang elicin (TMA). From the inactivation kinetics and the lack of a quenchi ng effect of polynucleotides on the fluorescence emission of the drug, it appears that, apart from the induction of DNA damage, other events are implicated in T7 phage dark inactivation. These results are impor tant for the interpretation of the photobiological effects of this typ e of compound.