Interestingly, in all models, (Z)-1 and (E)-1 remained bound to the region located above the top G-quadruplex plane (formed by G2, G15, G19 and G26). While (E)-1 was located nearer to the duplex region, (Z)-1 adjusted its position to get closer to the duplex-quadruplex junction (even embeding itselve into that junction in some of the simulations) (Figures S10 and S11). This observation may suggest that the (E)-1 binds preferentially at the junction part whereas (Z)-1 favors the duplex part, which seems to be in accordance with the NMR observations.