Lipophilic guanilic derivatives (lipoGs) dissolved in organic solvents can undergo different self-assembly pathways based on different H-bonded motifs, e.g., the cyclic discrete G-quartet, which forms in the presence of alkali-metal ions, and the “infinite” tape-like G-ribbon observed in the absence of ions. Using in-solution small-angle X-ray scattering, we analyzed a series of lipoGs dissolved in cyclohexane in the presence of different salts. The formation of G-quartet based supramolecular aggregates has been confirmed, evidencing the coexistence equilibrium of octamers and noncovalent molecular nanowires (the so-called G-quadruplexes). By global fitting the scattering data, the concentration of the two kinds of particles as well as the nanowire length have been derived as a function of temperature for the different compounds and salts. The thermodynamic parameters show that the self-assembly aggregation process is enthalpy driven, while the observed enthalpy−entropy compensation suggests that similar stacking interactions control the self-assembly of the different compounds. However, the strength of the stacking interactions, and then the nanowire stability, depends on the nature of templating cations and on their capacity to fill the central cavity of quadruplexes, with the order Sr+ < Na+ ≲ K+.

Small-Angle X‑ray Scattering Study of Self-Assembling Lipophilic Guanines in Organic Solvents: G‑Quadruplex Formation and Cation Effects in Cyclohexane / A. Gonnelli; M. G. Ortore; E. J. Baldassarri; G. P. Spada; S. Pieraccini; R. C. Perone; S. S. Funari; P. Mariani. - In: JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL. - ISSN 1520-6106. - STAMPA. - 117:(2013), pp. 1095-1103. [10.1021/jp3121929]

Small-Angle X‑ray Scattering Study of Self-Assembling Lipophilic Guanines in Organic Solvents: G‑Quadruplex Formation and Cation Effects in Cyclohexane

SPADA, GIAN PIERO;PIERACCINI, SILVIA;
2013

Abstract

Lipophilic guanilic derivatives (lipoGs) dissolved in organic solvents can undergo different self-assembly pathways based on different H-bonded motifs, e.g., the cyclic discrete G-quartet, which forms in the presence of alkali-metal ions, and the “infinite” tape-like G-ribbon observed in the absence of ions. Using in-solution small-angle X-ray scattering, we analyzed a series of lipoGs dissolved in cyclohexane in the presence of different salts. The formation of G-quartet based supramolecular aggregates has been confirmed, evidencing the coexistence equilibrium of octamers and noncovalent molecular nanowires (the so-called G-quadruplexes). By global fitting the scattering data, the concentration of the two kinds of particles as well as the nanowire length have been derived as a function of temperature for the different compounds and salts. The thermodynamic parameters show that the self-assembly aggregation process is enthalpy driven, while the observed enthalpy−entropy compensation suggests that similar stacking interactions control the self-assembly of the different compounds. However, the strength of the stacking interactions, and then the nanowire stability, depends on the nature of templating cations and on their capacity to fill the central cavity of quadruplexes, with the order Sr+ < Na+ ≲ K+.
2013
Small-Angle X‑ray Scattering Study of Self-Assembling Lipophilic Guanines in Organic Solvents: G‑Quadruplex Formation and Cation Effects in Cyclohexane / A. Gonnelli; M. G. Ortore; E. J. Baldassarri; G. P. Spada; S. Pieraccini; R. C. Perone; S. S. Funari; P. Mariani. - In: JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL. - ISSN 1520-6106. - STAMPA. - 117:(2013), pp. 1095-1103. [10.1021/jp3121929]
A. Gonnelli; M. G. Ortore; E. J. Baldassarri; G. P. Spada; S. Pieraccini; R. C. Perone; S. S. Funari; P. Mariani
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/393237
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