Fluorescence labelling of carbohydrates with 2-aminobenzamide (2AB)

2-Aminobenzamide (2AB) is a common fluorescence label attached to reducing oligosaccharides by a reductive amination procedure. Chemical investigation of the published literature procedure reveals labelling occurs by the expected mechanism for both protected and unprotected glucose derivatives to yield open-chain carbohydrates rather than result in the formation of any heterocyclic materials. Pentenyl glucosides may also be readily attached to the 2AB label by a sequence of dihydroxylation, periodate cleavage and subsequent reductive amination of the resulting aldehyde. :,AB labelling is compatible with deprotection of both acetate and benzyl protecting groups. (C) 2001 Elsevier Science Ltd. All rights reserved.