Addition of azobenzene-derivative 1 in its E configuration to an aqueous solution containing various guanosine borate esters induces a helical G-quartet based self-organization, stabilized by intercalation of the dye. The process is driven, in a domino fashion, by the initial host-guest interaction between the dye and a specific guanosine borate diester, whose structure can be thus assigned. This inclusion complex templates the formation of G-quartets. The quartets, in turn, pile up to form a supramolecular G-quadruplex structure, in which other G species present in solution are progressively included. The G-quadruplex can be reversibly broken and reformed by photoisomerization of the dye. This hierarchical and photosensitive self-assembly is unprecedented for simple guanosine derivatives.
Playing supramolecular dominoes with light: building and breaking a photoreversible G-quadruplex made from guanosine, boric acid and an azobenzene / Pieraccini, Silvia; Campitiello, Marilena; Carducci, Federica; Davis Jeffery, T; Mariani, Paolo; Masiero Stefano, .. - In: ORGANIC & BIOMOLECULAR CHEMISTRY. - ISSN 1477-0539. - STAMPA. - 17:(2019), pp. 2759-2769. [10.1039/c9ob00193j]