N,N-disubstituted 4-amino-3-chloroangelicins: interactions with DNA in the ground and in the excited states (365 nm)
Vedaldi, D.; Dall'Acqua, F.; Baccichetti, F.; Bombieri, G.; Schenone, P.; Mosti, L.
Il Farmaco; Edizione Scientifica 41(4): 270-280
1986
ISSN/ISBN: 0430-0920 PMID: 3709789 Document Number: 280798
The interactions between three N,N-disubstituted 4-amino-3-chloroangelicins and DNA in the ground and in the excited states have been examined. The three compounds form a molecular complex with DNA in the dark, but to a quite different extent. Spectrophotometric and fluorimetric data suggest that while 3-chloro-4-dimethylaminoangelicin (III) undergoes intercalation between two phase pairs of DNA, the compounds i.e. 3-chloro-4-methylphenyl amino angelicin (I) and its 5,6-dihydroderivative (II) should not undergo intercalation. Compound (I) photobinds to DNA to an extent similar to that of parent angelicin, while compound (III) photobinds to the macromolecule much more effectively. This fact may be attributed to the more suitable type of molecular complex (intercalation) formed by compound (III) with the macromolecular in respect to that formed by compound (I). The observed very low ability of compound (II) both to form a complex and to photobind with DNA can be ascribed primarily to the marked modification of the chromophore due to the saturation of the 5,6 double bond in the central benzene ring.