A closer look at the nitrogen next door: 1H-15N NMR methods for glycosaminoglycan structural characterization

► 1H-15N chemical shift correlations aid glycosaminoglycan characterization. ► HSQC-TOCSY extends 1H-15N correlations through the glucosamine ring. ► For N-sulfo- and N-acetylglucosamine 1H-15N HSQC-TOCSY is superior to IMPACT-HNMBC. ► IMPACT-HNMBC gives 15N chemical shifts of the 3-O-sulfoglucosamine amino group.