Study of cationic calixarenes interactions with nucelotides, DNA and RNA

Ena Otković

MSc Thesis, defended Sep. 22nd, 2021


Previously synthesized calix[4]arene and calix[6]arene compounds were characterized spectrophotometrically in a biologically relevant aqueous medium. The compounds show weak but applicable fluorescence allowing study of the noncovalent interactions with nucleoside-monophosphates, while interactions with double-stranded DNA/RNA were studied by competition with ethidium bromide and thremal denaturation experiment. Only cationic analogs showed biorelevant interactions within DNA minor groove or RNA major goove binding site. Neutral analogues do not interact with DNA/RNA, stressing importance of positive charge. The tested calixarenes bind nucleoside-monophosphates to form an intercaland type of calixarene-nucleobase complex, nucleobase inserted between the aryl-substituents at the calixarene rim. Neutral analogs bind nucleoside-monophosphates with higher affinity than cationic analogs but cationic analogs show fluorimetric selectivity towards pyrimidine nucleobases.