Fluorescent cyanine-guanidiniocarbonyl-pyrrole conjugate with pH-dependent DNA/RNA recognition and DPP III fluorescent labelling and inhibition properties

Here designed and prepared cyanine-guanidinocarbonyl-pyrrole conjugate (Cy-GCP), intrinsically non-fluorescent, revealed fluorescent switch-on recognition of various secondary structures of ds-DNA and ds-RNA. Moreover, at the same submicromolar concentrations, DNA/RNA recognition was observed by selective induced (I)CD pattern in the visible range. Preliminary results showed that Cy-GCP strongly interacted with DPP III enzyme, switching-on the fluorescence upon binding and inhibiting enzyme action with efficiency comparable to the best-known inhibitor tynorphin.