title: Use of the derivatizing agent 4-aminobenzoic acid 2-(diethylamino)ethyl ester for high-sensitivity detection of oligosaccharides by electrospray ionization mass spectrometry.
abstract: A method for the high-sensitivity detection of oligosaccharides by electrospray ionization mass spectrometry (ESI-MS) is reported. The method involves the chemical derivatization with 4-aminobenzoic acid 2-(diethylamino)-ethyl ester (ABDEAE). This derivative, which contains a 2-(diethylamino)ethyl group, having a high proton affinity, enhances the ionization efficiency of analytes in the positive ESI mode. Experiments using maltohexaose as a model oligosaccharide revealed that derivatization with ABDEAE gave a remarkably large increase in molecular ion abundance. Using a mixture of acetonitrile, 2-methoxyethanol, 2-propanol, and water (1:1:1:1 v/v/v/v) as solvent for ESI, ABDEAE-derivatized maltohexaose could be detected at a level of 10 fmol. This represents a 5000-fold improvement in sensitivity over underivatized maltohexaose. ESI tandem mass spectrometry of the ABDEAE-derivatized maltohexaose provides structural information at the low-picomole level. In this spectrum, 1,5X' and 0,2A" series of sequence ions, arising from ring cleavage, were observed as the predominant ions.
authors.affiliation: Institute for Protein Research, Osaka University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoshino
authors.forename: T
authors.initials: T
authors.lastname: Takao
authors.forename: H
authors.initials: H
authors.lastname: Murata
authors.forename: Y
authors.initials: Y
authors.lastname: Shimonishi
mesh_terms: D000838:Anions; D001665:Binding Sites; D002412:Cations; D002851:Chromatography, High Pressure Liquid; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D011343:Procaine / Q000737:chemistry* / Q000378:metabolism; D011522:Protons; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000838:Anions; D002412:Cations; D009844:Oligosaccharides; D011522:Protons; C016549:maltohexaose; D011343:Procaine