Interactions of tetraaza macrocycles with DNA and RNA in aqueous media

U okviru ovog diplomskog rada provedena je spektroskopska karakterizacija vodenih otopina spojeva DA1, DA2, DA3 i DK. Ispitane su interakcije tih spojeva s prirodnim i sintetskim polinukleotidnim supstratima UV/Vis i CD spektroskopijom i viskozimetrijom te je ispitan njihov utjecaj na vijabilnost stanica MTT testom. Heterosupstituirani adenin na makrocikličkoj jezgri je uzrokovao povećani afinitet spoja DA1 prema jednolančanom polinukleotidu poli dT u odnosu na ostale polinukleotide. Drugi spojevi nisu pokazali takvu selektivnost vezanja. Obradom dobivenih podataka pomoću Scatchardove jednadžbe metodom nelinearne regresije izračunate su konstante stabilnosti. CD titracije polinukleotida sa spojem DA1 su potvrdile specifično vezanje tog spoja na poli dT izrazitim ICD odgovorom. Kontrolni spoj DK, s vezanom metilnom skupinom umjesto adenina, puno je slabije utjecao na CD polinukleotida i nije pokazao značajan ICD spektar u ispitanim omjerima. Spojevi DA2 i DA3, s duljom premosnicom od spoja DA1, nisu uspjeli uspostaviti strukturalnu stabilnost koja bi se pokazala intenzivnijim ICD spektrom. Spojevi DA1 i DA3, ispitani MTT testom, pokazali su se kao slabo toksični.As a part of this thesis, a spectroscopic characterization of aqueous solutions of compounds DA1, DA2, DA3 and DK was carried out. Interactions between these compounds and natural and synthetic polynucleotide substrates were examined by UV/Vis spectroscopy, CD spectroscopy and viscometry, and a MTT assay was performed to determine effect of the compounds on cell viability. Hetero substituted adenine attached to the macrocyclic core caused an increased affinity of compound DA1 towards single-stranded polynucleotide poly dT in respect to other polynucleotides. Other compounds have not shown such binding selectivity. The stability constant was calculated by using the Scatchard equation and nonlinear regression. CD titrations of polynucleotides with the compounds have verified the specific binding of DA1 to poly dT with a strong ICD response. Compound DK, with a methyl group instead of an adenine, that was used as a control, had a much weaker effect on CD spectra of polynucleotides and has not shown a significant ICD signal in ratios tested. Compounds DA2 and DA3, containing a shorter linker than DA1, have not been able to establish a higher degree of structural stability to be reported by a stronger ICD spectra. Compounds DA1 and DA3 have been tested with a MTT assay, and have not proven to be toxic