beta-D-(1,4), beta-D-(1,3) "mixed linkage" xylans from red seaweeds of the order Nemaliales and Palmariales

ADRIANO G. VIANA.; MIGUEL D. NOSEDA; ALAN G. GONCALVES; MARIA EUGENIA R.. DUARTE; NAIR YOKOYA; MARIA C. MATULEWICZ; ALBERTO S. CEREZO

CARBOHYDRATE RESEARCH

ELSEVIER SCI LTD

Lugar: Oxford; Año: 2011 vol. 346 p. 1023 - 1028

0008-6215

Xylans from five seaweeds belonging to the order Nemaliales (Galaxaura marginata, G. obtusata, Tricleocarpa cylindrica, T. fragilis and Scinaia halliae) and one of the order Palmariales (Palmaria palmata) collected in the Brazilian coasts were extracted with hot water and purified from acid xylomannans and/or xylogalactans through Cetavlon precipitation of the acid polysaccharides. The beta-D-(1,4), beta-D-(1,3) "mixed linkage" structures were determined using methylation analysis, and 1D and 2D NMR spectroscopy. The presence of large sequences of beta-(1,4)-linked units suggests transient aggregates of ribbon- or helical-ordered structures that would explain the low optical rotations.