Tetrahydrobenzo- and benzofurobenzopyrones as a new class of potential photoreagents toward DNA.

The synthesis and the photobiological activity of new tetrahydrobenzo- and benzofurobenzopyrone derivatives carrying at position 4 of benzopyrone ring of furobenzopyrone moiety a phenyl, or a methyl group with a linear structure or with various angular arrangements, are reported. The new compounds are characterized by having an additional cyclohexene or phenyl ring condensed at the 2, 3 double bond of the furan ring of furobenzopyrone nucleus. The syntheses were performed starting from the appropriate hydroxybenzopyrones on which the tetrahydrobenzofuran or benzofuran moiety was built, which look most promising for enhancement of photoreactivity of compounds toward DNA. All the synthesized compounds were screened for photosensitizing activity and some of them exhibited good activity also a certain effect was observed in the dark.