Figure 34.

IRMPD spectra of heparan sulfate (HS) and chondroitin sulfate (CS) disaccharides. Scheme: Δ^4,5 unsaturated disaccharides derived from HS (left) and CS (right). (A, B) IRMPD spectra of deprotonated Hp II-A (red: [Hp II-A – H]⁻) and Hp III-A (black: [Hp III-A – H]⁻) in the 550–1850 and 2700–3700 cm^–1 spectral ranges. Right panels: IRMPD spectra of CS-A (red) and CS-C (blue) in different charge states. (C) Singly deprotonated [CS-A – H]⁻ and [CS-C – H]⁻. (D) Doubly deprotonated [CS-A – 2H]^2– and [CS-C – 2H]^2–. (E) NH₄⁺ cationic complexes [CS-A + NH₄]⁺ and [CS-C – NH₄]⁺. Figure reproduced with permission from ref (537). Copyright 2017 American Chemical Society.