SPECIFIC INTERACTIONS OF ANTIRETROVIRALY ACTIVE-DRUG HYPERICIN WITH DNA AS STUDIED BY SURFACE-ENHANCED RESONANCE RAMAN-SPECTROSCOPY

Surface-enhanced resonance Raman spectroscopy was employed to study th e interaction of hypericin with DNA and its model molecules poly(rA) a nd poly(rG). The obtained results clearly demonstrate that hypericin a ctually interacts with DNA and that terminal hydroxyl and carbonyl gro ups are directly implicated in this interaction. A detailed study of D NA structural marker bands in the 600-850 cm(-1) region reveals that g uanine plays a crucial role in this interaction. This deduction was co nfirmed by studying the interaction of hypericin with poly(rG) complex , in which evident changes concerning both hydroxyl and carbonyl group s bands of hypericin and guanine ring breathing band of the polynucleo tide can be observed. In view of these results, a model for the hyperi cin-DNA interaction is proposed.