Issue in Honor of Prof. Rosa Lederkremer ARKIVOC 2005 (xii) 319-331
Autohydrolysis of a partially cyclized mu/nu-carrageenan and structural elucidation of the oligosaccharides by chemical analysis, NMR spectroscopy and UV-MALDI mass spectrometry
Marina Cianciaa, Yasuto Satob, Hiroshi Nonamic, Alberto S. Cerezod, Rosa Erra-Balsellsd, and María C. Matulewicz*d
a Cátedra de Química Orgánica, CIHIDECAR-CONICET, Departamento de Biología Aplicada y Alimentos, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, 1417 Buenos Aires, Argentina b The United Graduate School of Agricultural Sciences, Ehime University, Tarumi, Matsuyama 790-8566, Japan c Faculty of Agriculture, Ehime University, Tarumi, Matsuyama 790-8566, Japan d Departamento de Química Orgánica, CIHIDECAR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina E-mail:
[email protected] (MCM)
Dedicated to Prof. Rosa M. de Lederkremer on occasion of her 70th anniversary
Abstract
A partially cyclized mu/nu-carrageenan from Gigartina skottsbergii was submitted to autohydrolysis and the resulting mixture of oligosaccharides was fractionated using sequential dialysis through tubings of molecular weight cutoff 12000, 3500 and 1000. In this way four fractions were separated and characterized. Structural analysis of the major fraction, obtained from the solution inside the dialysis tubing of molecular weight cutoff 12000 (D120), was carried out. A significant difference was found by 13C NMR spectroscopy and UV-MALDI-TOF mass spectrometry: in the 13C NMR spectrum the reducing end-chain unit was the hydrated aldehyde of 3,6-anhydrogalactose while the UV-MALDI-TOF mass spectrum showed an unimodal distribution of even and odd peaks, suggesting fragmentation of glycosidic linkages.
Keywords: Sulfated galactans, carrageenans, autohydrolysis, sulfated oligosaccharides, structural analysis, UV-MALDI-TOF-MS, nor-harmane
ISSN 1424-6376 Page 319 ©ARKAT USA, Inc
