Selective complexation of divalent cations by a cyclic α,β-peptoid hexamer: a spectroscopic and computational study

De Santis, E. and Edwards, A. A. and Alexander, B. D. and Holder, Simon J. and Taillefumier, C. and Faure, S. and Nielsen, B. V. and Waters, L. and Siligardi, G. and Hussain, R. and Biesse-Martin, A.-S. and Mistry, D. (2016) Selective complexation of divalent cations by a cyclic α,β-peptoid hexamer: a spectroscopic and computational study. Organic and Biomolecular Chemistry, . ISSN 1477-0520. (doi:https://doi.org/10.1039/C6OB01954D) (Full text available)

Abstract

The first report on metal binding ability of a cyclic α,β-peptoid hexamer towards a selection of metal cations is presented. We describe the qualitative and quantitative analysis of the complexation properties towards cations of a cyclic peptoid hexamer composed of alternating α- and β-peptoid monomers, which bear exclusively chiral (S)-phenylethyl side chains (spe) that have no noticeable chelating properties. The binding of a series of monovalent and divalent cations was assessed by 1H NMR, circular dichroism, fluorescence and molecular modelling. In contrast to previous studies on cations binding by 18-membered α-cyclopeptoid hexamers, the 21-membered cyclopeptoid cP1 did not complex monovalent cations (Na+, K+, Ag+) but showed selectivity for divalent cations (Ca2+, Ba2+, Sr2+ and Mg2+). Hexacoordinated C-3 symmetrical complexes were demonstrated for divalent cations with ionic radii around 1 Å (Ca2+ and Ba2+), while 5-coordination is preferred for divalent cations with larger (Ba2+) or smaller ionic radii (Mg2+).

Item Type:	Article
Uncontrolled keywords:	foldamers, peptoids, metal binding
Subjects:	Q Science Q Science > QD Chemistry Q Science > QD Chemistry > QD431 Organic Chemistry- Biochemistry- Proteins, peptides, amino acids
Divisions:	Faculties > Sciences > School of Physical Sciences Faculties > Sciences > School of Physical Sciences > Functional Materials Group Faculties > Sciences > Medway School of Pharmacy
Depositing User:	Alison Edwards
Date Deposited:	03 Nov 2016 09:57 UTC
Last Modified:	05 Apr 2017 16:24 UTC
Resource URI:	https://kar.kent.ac.uk/id/eprint/58354 (The current URI for this page, for reference purposes)
Holder, Simon J.:	https://orcid.org/0000-0001-8977-9257