Among novel bis-nucleobase-phenanthridinium conjugates bis-uracil analogue stabilized significantly more effective poly-dA-poly-dT and poly-AH(+)-poly-AH(+) than adenine analogue and reference compound . For the alternating poly-dAdT-poly-dAdT however, the binding preference is lost, pointing to the importance of specific interactions of uracils of with homopolynucleotides containing consecutive adenines.

A set of (p-cymene)-ruthenium amino acid bioconjugates 1 and 2 is reported.The bioconjugates 2 show micromolar affinity for proteins.Increased potency and selectivity of 2 towards cancer cell lines is detected.The cytotoxicity of bioconjugates 2 is in correlation with their BSA binding constants.Cell stress response includes increase of cells in S phase of cell cycle, induction of autophagy and use of GSH as detoxification mechanism.

A series of novel phenanthridine–nucleobase conjugates were prepared and studied by spectroscopic methods. An analysis of 1H NMR, UV–Vis and fluorescence spectra in aqueous media revealed intramolecular aromatic stacking interactions between the phenanthridinium unit and the nucleobase, due to the conformation of the molecules. Fluorimetric titrations showed that phenanthridinium–nucleobase conjugates 8, 10 and reference phenanthridine compound 12 form 1:1 non‐covalent complexes with nucleotides in water with binding constants ranging from 10 to 100 mol−1 dm3. Interestingly, compounds 9 and 11 form intercalative‐type 1:1 complexes with the nucleotide aromatic unit inserted between phenanthridinium and covalently attached nucleobase, yielding binding constants of 103–104 mol−1 dm3. Aromatic ππ stacking interactions were found to be dominant in complexes with nucleotides of all compounds studied. Copyright © 2002 John Wiley & Sons, Ltd.

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Among series of novel bis-phenanthridinium -nucleobase conjugates, the adenine derivative revealed high (logKs = 6.9 M -1 ) and selective affinity toward complementary nucleotide (UMP), accompanied by specific change in the UV/Vis spectrum of phenanthridine subunits, differing significantly from changes caused by addition of other nucleotides. High stability and selectivity of adenine-conjugate/UMP non-covalent complex is according to the molecular modelling studies correlated to the number of inter-and intramolecular aromatic stacking interactions between phenanthridinium subunits, covalently attached adenine and added UMP, while selectivity of adenine-conjugate toward UMP in respect to other nucleotides is most likely the consequence of additional hydrogen bonding between UMP and adenine.