ABSTRACT This work focuses on two chiral Ru(II) polypyridyl complexes, Λ‐Ru(bpy) 2 (bipp) 2+ (Λ‐ 1 ) and Δ‐Ru(bpy) 2 (bipp) 2+ (Δ‐ 1 , bipp = 2‐benzimidazoyl‐pyrazino2,3‐ f 1,10phenanthroline) were developed. The stabilizing effects and structural influence of two enantiomers on the RNA triplex were investigated by spectroscopy and viscometry. The results of the UV–vis absorption spectroscopy titration experiments indicate that both enantiomers may bind to the triplex RNA via an intercalation mode, as evidenced by the hypochromic and red shifts observed in the absorption spectrum. Further quantitative analysis demonstrated that, under identical experimental conditions, the Δ‐enantiomer exhibited a marginally stronger interaction than its Λ‐counterpart. These conclusions were further supported by luminescence spectroscopy and viscosity experiments. Circular dichroism (CD) spectroscopy results indicate that both enantiomers significantly induce conformational changes in RNA triplex complexes, revealing strong intermolecular binding to the RNA triplex. Thermal denaturation analysis demonstrated that both enantiomers significantly and preferentially stabilized the RNA triplex third‐strand. However, no significant chiral selectivity was observed in the thermal denaturation data of the present work. This work elucidates the interaction mechanism between chiral ruthenium(II) complexes and RNA triplex, providing a critical theoretical basis for stabilizing RNA triplex.
Ling et al. (Fri,) studied this question.