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

De Santis, E., Edwards, A.A., Alexander, B.D., Holder, S.J., Biesse-Martin, A.-S., Nielsen, B.V., Mistry, D., Waters, L., Siligardi, G., Hussain, R., and others. Faure, S., and Taillefumier, C. (hide) (2016) Selective complexation of divalent cations by a cyclic α,β-peptoid hexamer: a spectroscopic and computational study. Organic and Biomolecular Chemistry, 14 (48). pp. 11371-11380. ISSN 1477-0520. (doi:10.1039/C6OB01954D)

Abstract

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
DOI/Identification number:	10.1039/C6OB01954D
Uncontrolled keywords:	foldamers, peptoids, metal binding
Subjects:	Q Science > QD Chemistry > QD431 Organic Chemistry- Biochemistry- Proteins, peptides, amino acids
Divisions:	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:	12 Jul 2019 14:49 UTC
Resource URI:	https://kar.kent.ac.uk/id/eprint/58354 (The current URI for this page, for reference purposes)
Holder, S.J.:	https://orcid.org/0000-0001-8977-9257