Synthesis, characterization and DNA intercalation of a furonaphthopyronone as a novel analogue of furocoumarin

As a novel analogue of furocoumarin,2H-4,8-dimethylfuro[2′, 3′: 5,6]naphtho[1, 2-b] pyran-2-one 6 was sythesized through Pechmann condensation, etherification, Claisen rear rangement, acetylation, bromine addition and cyclization of 1, 5-naphthalenediol. The sructures of 6 and its precusors were fully characterized by ¹H NMR, MS, IR and elemental analysis. The DNA-intercalate activity of 6 and 7 was investigated in DMSO-Tris HCl system and their apparent Scatchard binding constants were calculated. It was found that 7 intercalate into DNA more efficiently than 6 due to the different substituents on the furan ring.