Organic chemistry

Enzyme

Disaccharide

Xylobiose

Nuclear magnetic resonance spectroscopy

Stereochemistry

Crystallography

Biology

Hydrogen bond

Circular dichroism

Xylanase

Chemistry

Ecology

Amide

Helix (gastropod)

Snail

Molecule

Foldamer

Angewandte Chemie International Edition

Xylobiose sequestration in a helical aromatic oligoamide capsule was evidenced by circular dichroism, NMR spectroscopy, and crystallography. The preparation of the 5 kDa oligoamide sequence was made possible by the transient use of acid‐labile dimethoxybenzyl tertiary amide substituents that disrupt helical folding and prevent double helix formation. Binding of other disaccharides was not detected. Crystallographic data revealed a complex composed of a d ‐xylobiose α anomer and two water molecules accommodated in the right‐handed helix. The disaccharide was found to adopt an unusual all‐axial compact conformation. A dense network of 18 hydrogen bonds forms between the guest, the cavity wall, and the two water molecules.

Selective Encapsulation of Disaccharide Xylobiose by an Aromatic Foldamer Helical Capsule