Prado Héctor J, Ciancia Marina, Matulewicz María C
Departamento de Química Orgánica, CIHIDECAR-CONICET, Facultad de Ciencias Exactas y Naturales, UBA, Pabellón 2, Ciudad Universitaria, 1428EGA Buenos Aires, Argentina.
Carbohydr Res. 2008 Mar 17;343(4):711-8. doi: 10.1016/j.carres.2007.12.024. Epub 2008 Jan 11.
Polysiphonia nigrescens was sequentially extracted with water at room temperature, 70 and 90 degrees C. The extracts were analyzed and the major one, isolated at 70 degrees C, was fractionated by ion-exchange chromatography, eluting with water and solutions of increasing sodium chloride concentration; five main fractions were separated. Structural analysis, carried out by methylation analysis and NMR spectroscopy, showed that four of these were partially cyclized agarans that were highly substituted on C-6 mainly with sulfate, although methyl ether and single stubs of beta-D-xylose were found in minor proportions. A fifth fraction comprising 6-sulfated agarose was also isolated. The use of 2D NMR techniques allowed us to assign the 1H and 13C NMR resonances of the G6S-->L6S diad for the first time.
黑多管藻依次用室温的水、70℃和90℃的水进行提取。对提取物进行分析，在70℃提取得到的主要提取物通过离子交换色谱法进行分离，用水和氯化钠浓度递增的溶液进行洗脱；分离出了五个主要馏分。通过甲基化分析和核磁共振光谱进行的结构分析表明，其中四个是部分环化的琼脂糖，在C-6位上高度被硫酸根取代，不过也发现了少量比例的甲基醚和β-D-木糖单链。还分离出了包含6-硫酸化琼脂糖的第五个馏分。二维核磁共振技术的使用使我们首次能够确定G6S→L6S二联体的1H和13C核磁共振共振峰。
