TY - JOUR A1 - Weißenstein, Annike A1 - Vysotsky, Myroslav O. A1 - Piantanida, Ivo A1 - Würthner, Frank T1 - Naphthalene diimide–amino acid conjugates as novel fluorimetric and CD probes for differentiation between ds-DNA and ds-RNA JF - Beilstein Journal of Organic Chemistry PY - 2020/// VL - 16 SP - 2032 EP - 2045 SN - 1860-5397 DO - 10.3762/bjoc.16.170 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.16.170 KW - amino acid–fluorophore conjugate KW - circular dichroism KW - DNA/RNA recognition KW - fluorescence KW - intercalation KW - naphthalene diimide N2 - Two novel unnatural amino acids, prepared by linking a dicationic purple-coloured and fluorescent naphthalene diimide (NDI) at core position to amino acid side chains of variable length, strongly interacted with ds-DNA/RNA by threading intercalation. Different from a reference NDI dye with identical visible range absorbance (520–540 nm) and Stokes shifts in emission (+60 nm, quantum yield > 0.2), only these amino acid–NDI conjugates showed selective fluorimetric response for GC-DNA in respect to AT(U)-polynucleotides. The DNA/RNA binding-induced circular dichroism (ICD) response of NDI at 450–550 nm strongly depended on the length and rigidity of the linker to the amino acid unit, which controls the orientation of the NDI unit inside within the intercalative binding site. The ICD selectivity also depends on the type of polynucleotide, thus the studied NDI dyes act as dual fluorimetric/ICD probes for sensing the difference between here used GC-DNA, AT-DNA and AU-RNA. ER -