title: Matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass spectrometry of sulfated mannans from the red seaweed Nothogenia fastigiata.
abstract: Matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass spectrometry (UV-MALDI-TOF-MS) was applied to sulfated xylo-mannan fractions from Nothogenia fastigiata in order to determine their molecular weights and distribution profiles. The number-average molecular weight calculated from the spectra was similar to that determined by chemical end-group analysis for the lower molecular weight fractions. For the other fractions, the number-average molecular weight was lower than that chemically determined; the increased difference may be attributed to higher desorption difficulties and, consequently, mass-dependent discrimination. A reconstructed spectrum, using the peaks obtained from all the fractions, suggested an unimodal distribution. The best results were obtained by using 2,5-dihydroxybenzoic acid as matrix doped with 1-hydroxyisoquinoline and with harmane and nor-harmane.
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Argentina.
authors.forename: R
authors.initials: R
authors.lastname: Erra-Balsells
authors.forename: A A
authors.initials: AA
authors.lastname: Kolender
authors.forename: M C
authors.initials: MC
authors.lastname: Matulewicz
authors.forename: H
authors.initials: H
authors.lastname: Nonami
authors.forename: A S
authors.initials: AS
authors.lastname: Cerezo
mesh_terms: D005841:Gentisates; D062385:Hydroxybenzoates / Q000494:pharmacology; D008351:Mannans / Q000032:analysis / Q000737:chemistry*; D008970:Molecular Weight; D012624:Seaweed / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods* / Q000592:standards; D013431:Sulfates / Q000737:chemistry; D014466:Ultraviolet Rays; D014994:Xylose / Q000737:chemistry
chemical_list: D005841:Gentisates; D062385:Hydroxybenzoates; D008351:Mannans; D013431:Sulfates; D014994:Xylose; C010925:2,5-dihydroxybenzoic acid