Table 3. Shift of melting temperature, ΔT m, of quadruplex DNA F21T in the presence of the ligands 2 and 4b–d at different LDR without and with the duplex DNA ds26 as determined by fluorimetric thermal denaturation studies.
| Ligand | ΔT
m/°C at different LDR
a
|
|||
| Without ds26
|
With ds26
b
|
|||
| 2.5 | 5.0 | 2.5 | 5.0 | |
| 2BF4 | 21.7 | 27.0 | 20.0 | 26.5 |
| 4b | 28.2 | 31.6 | 21.3 | 30.7 |
| 4c | 25.9 | 31.8 | 23.3 | 29.4 |
| 4d | 28.1 | 32.9 | 25.5 | 31.4 |
aΔT m of F21T; c F21T = 0.2 μM (in oligonucleotide); KCl–LiCl–Na–cacodylate buffer (10 mM K+, 10 mM Na+, 90 mM Li+, pH 7.2); λ ex = 470 nm; λ em = 515 nm; estimated error: ±0.5 °C of the given data.
b c ds26 = 3.0 μM.