摘要
从籽瓜中提取籽瓜多糖(SWP),用氯磺酸-吡啶法制备籽瓜多糖硫酸酯(SSWP)。以籽瓜多糖硫酸酯中硫含量为指标,依据响应面设计对影响硫酸酯中硫含量的反应时间、温度和酯化试剂的比例(氯磺酸∶吡啶)三个因素进行优化组合。得出最佳组合条件为:反应时间3.2h,温度61℃,酯化试剂的比例(氯磺酸∶吡啶)1∶1.3。在此条件下,籽瓜多糖硫酸酯中硫含量可达到11.98%。用红外光谱对籽瓜多糖进行了扫描,在1250.76、810.74cm-1处出现了新的吸收峰,说明硫酸化是成功的。用GC-MS分析其单糖组成,结果表明籽瓜多糖硫酸酯由鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖、半乳糖六种单糖组成,摩尔比为4.29∶11.72∶8.66∶5.35∶13.62∶56.36。用体积排阻色谱测得籽瓜多糖硫酸酯的分子量,重均分子量Mn=2.717×105,数均分子量Mw=1.232×105。通过测定籽瓜多糖和籽瓜多糖硫酸酯对DPPH自由基、羟自由基的清除率,表明籽瓜多糖硫酸酯对羟基自由基及DPPH自由基的清除率比未酯化前显著提高。
Watermelon polysaccharide（SWP） was extracted from watermelon and watermelon polysaccharide sulfate（SSWP） was prepared by chlorosulfonic acid-pyridine. The sulfur content in sulfated watermelon polysaccharide as an indicator, based on response surface design （Response surface methodology, RSM）,the combination of three factors：the effect of sulfur in sulfate reaction time,temperature and esterification reagent ratio（chlorosulfonic acid：pyridine） was optimized. The reaction time of 3.2h,reaction temperature of 61℃,and the ratio of esterification of reagent（chlorosulfonic acid ：pyridyl） which was 1：1.3 were the optimum combination of conditions. Under this condition,the content of sulfur in sulfated watermelon polysaccharides was up to 11.98%. Watermelon polysaccharide were scanned by IR spectra showing new absorption peak appeared at 1250.76cm^-1 and 810.74cm^-1,which indicated that the sulfation was successful. Its monosaccharide composition was analysed by GC-MS,which showed that watermelon polysaccharide was composed of six kinds of monosaccharide .. rhamnose, arabinose, xylose, mannose, glucose, galactose, and the molar ratio was 4.29： 11.72：8.66：5.35：13.62：56.36. Its molecular weight was measured by size exclusion chromatography（SEC）, Mn= 2.717×10^5, Mw=1.232×10^5. By measuring the scavenging rates of sulfated watermelon polysaccharide on DPPH radicals,hydroxyl radical and reducing power,it showed that the sulfated watermelon polysaccharides had significantly improved on scavenging rates and reducing power of hydroxyl radical and DPPH radical than the unesterified ones before.
出处
《食品工业科技》
CAS
CSCD
北大核心
2014年第14期107-113,共7页
Science and Technology of Food Industry
基金
国家自然基金(31200255)
西南突发性灾害应急与防控技术集成与示范(2012BAD36B04)
关键词
籽瓜多糖
硫酸化
化学结构
抗氧化活性
watermelon polysaccharides
sulfated
chemical structure
antioxidant activity
