A Stereochemically Driven Supramolecular Polymerisation

作者:Tasca Elisamaria; D'Abramo Marco; Galantini Luciano; Giuliani Anna Maria; Pavel Nicolae Viorel; Palazzo Gerardo*; Giustini Mauro*
来源:Chemistry - A European Journal, 2018, 24(32): 8195-8204.
DOI:10.1002/chem.201800644

摘要

Anthracyclines self-assemble in water into dimers. In the presence of sufficiently high salt (NaCl) concentrations, solutions of the antibiotic doxorubicin, but not those of the closely related molecules daunomycin and epirubicin, turn into gels barely compatible with the presence of small oligomers. The use of spectroscopic, scattering, imaging and computational techniques, allowed light to be shed on the self-assembly process that triggered doxorubicin gelification. A complex picture emerged, with doxorubicin molecules assembled into long, highly chiral, supramolecular aggregates made of hundreds of units, showing redshifted fluorescence spectra, very short fluorescence lifetimes and small-angle X-ray scattering profiles compatible with long cylinders. The involvement of specific chemical groups and the need for a specific stereochemistry of the monomers in the formation of a hydrogen-bond network to stabilise the supramolecular aggregates was supported by molecular dynamics calculations. A salt-induced, temperature-dependent, cooperative nucleation-elongation supramolecular polymerisation of the doxorubicin molecules is deduced.

  • 出版日期2018-6-7