A cucurbit[8]uril spongeElectronic supplementary information (ESI) available: Experimental details and spectral data are available. See DOI: 10.1039/c2ob26774h

This paper describes a convenient approach to quantitative removal of the synthetic host cucurbit[8]uril (Q8) from aqueous mixtures using a sepharose resin coated in memantine groups to selectively sequester Q8 in the presence of competing hosts and guests. The "Q8 sponge" can separate Q8 from Q6 and reverse the Q8-mediated dimerization of peptides. Sepharose functionalized with memantine groups selectively sequesters cucurbit[8]uril from mixtures, enabling reversal of peptide dimerization and separation of cucurbit[ n ]uril homologues.