Interaction of thiopyrylium salts with DNA

Interaction of DNA with thiopyrylium salts, 4-(4'-dimethylaminostyryl)-2,6- diphenylthiopyrylium chloride (I) and 4-methyl-2,6-diphenylthiopyrylium chl oride (II) was examined. The character of interaction of the compounds with DNA was established by CD and footprinting on the fragment of pUC19 plasmi d with the use of DNase I. Compound I is bound with DNA mainly at CAA and C GG sites. There are: two types of complex of compound I with DNA, having th e ratios of bound ligand molecules to DNA base pairs of 0.25 and 1.4. No in teraction of compound II with the nucleic acid was revealed.