[关键词]
[摘要]
研究了超声波处理条件下二甲基亚砜中无水碳酸钾催化棉籽糖和月桂酸甲酯的酯交换反应,得到了酯化位置不同的两种棉籽糖月桂酸单酯。薄层层析(TLC)分离棉籽糖月桂酸酯的理想条件为:点样量4 μL,以氯仿/甲醇/冰乙酸(V/V/V, 75:25:4)展开10 min,用10%磷钼酸乙醇溶液均匀喷雾后在105 ℃显色10 min。硅胶柱层析分离棉籽糖酯的理想条件为:1 g样品溶于3 mL的洗脱剂,过15 mm×700 mm硅胶(200~300目),流动相为TLC展开剂配比,流速为1 mL/min,10 min收集一份洗脱液。对纯化后的组分采用高效液相(HPLC),红外光谱(IR),质谱(MS),及核磁共振(1H-NMR、13C-NMR)进行了结构鉴定和表征,确定两单酯组分分别为1’’-棉籽糖月桂酸酯和6’’-棉籽糖月桂酸酯。同时测定并比较了两种单酯的溶解性和热稳定性,结果表明两种单酯具有相似的溶解性和热稳定性。
[Key word]
[Abstract]
Raffinose long-chain fatty acid monoester, acylated at the 1”-and 6”- positions, was synthesized in dimethylsulfoxide by the acylation of raffinose with methyl laurate under reduced pressure with ultrasound irradiation. TLC analysis of 4μL reaction mixture were carried out on silica gel G plates using chloroform-methanol-aceticacid (V/V/V, 75:25:7) as eluent. Spots were located by spraying with 10% of phosphomolybdic acid hydrate in ethanol and heated at 105 ℃ for 10min. The product was then separated with silica gel column chromatography by dissolving 1 g sample in eluent and then eluted by chloroform-methanol-acetic acid on a 15 mm × 700 mm silica gel column (200~300 mesh) at flow rate of 1 mL/min. The eluent of 1 bottle/10 min was collected and the purified products were analyzed by HPLC, IR, MS and NMR, and identified as 1’’-O-lauroylraffinose and 6’’-O-lauroylraffinose. The two lauroylraffinose isomerides had similar solubility in polar solvent and high thermal stability.
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[基金项目]
“十二五”农村领域国家科技计划课题(2011BAD02B04)。