The self-assembly of a lipophilic guanosine nucleoside into polymeric columnar aggregates: the nucleoside strucutre contains sufficient information to drive the process towards a strikingly regular polymer.
Lipophilic guanosine derivatives act as self-assembled ionophores. In the presence of alkali metal ions in organic solvents, these G derivatives can form tubular polymeric structures. The molecular aggregates formed by 3',5'-didecanoyl-2'-deoxyguanosine (1) have been characterised by SANS and NMR spectroscopy. The polymer is structured as a pile of stacked G quartets held together by the alkali metal ions that occupy the column's central channel. The deoxyribose moieties, with their alkyl substituents, surround the stacked G quartets, and the nucleoside's long-chain alkyl tails are in intimate contact with the organic solvent. In this polymeric structure, there is an amazing regularity in the rotamers around the glycosidic bond within each G quartet and in the repeat sequence of the G quartets along the columns. In hydrocarbon solvents, these columnar aggregates form lyomesophases of the cholesteric and hexagonal types.
Dipartimento di Chimica Organica A. Mangini Università di Bologna, Italy.
E
E
Mezzina
P
P
Mariani
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R
Itri
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S
Masiero
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S
Pieraccini
G P
GP
Spada
F
F
Spinozzi
J T
JT
Davis
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G
Gottarelli
D001704:Biopolymers / Q000737:chemistry; D006151:Guanosine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation
D001704:Biopolymers; D006151:Guanosine