摘要
地衣植物老龙皮富含多糖和三萜皂苷类化合物,是一种资源丰富的具有抗炎、抗氧化等活性的中草药。以老龙皮为原料,通过甲醇抽提脱脂、水浸提、三氯乙酸(TCA)法脱蛋白等方式粗提,然后分别采用梯度浓度乙醇分级沉淀法和DEAE-52纤维素柱层析的方法对老龙皮多粗多糖进行分级纯化。梯度浓度乙醇(乙醇质量浓度分别为15%,30%,50%和70%)分级沉淀得到4种多糖组分,以DEAE-52纤维素柱层析法洗脱得到5种老龙皮多糖组分。采用高效阴离子色谱(HPAEC)与红外光谱法(FT-IR)分析了老龙皮多糖组分的单糖组成和结构。研究结果表明,老龙皮多糖的单糖组成主要有阿拉伯糖、半乳糖、葡萄糖、甘露糖和木糖。其中,甘露糖含量最高,其次是半乳糖和葡萄糖。老龙皮多糖的红外光谱特征峰为3 417,2 911,1 659,1 400,1 026和831 cm^-1。利用乙醇分级沉淀和DEAE-52纤维素柱层析洗脱所得的9种老龙皮多糖组分进行体外抗氧化活性研究,结果显示老龙皮多糖具有较强的清除DPPH自由基能力和总还原力。其中:50%质量浓度乙醇沉淀的老龙皮多糖组分的清除能力最强,清除率达80.10%;15%质量浓度乙醇沉淀的老龙皮多糖组分的还原能力最强,其吸光值最高为0.74。
Being rich in polysaccharides and triterpene saponins,Lobariakoor kauae Yoshim is a resource-rich Chinese herbal medicine with anti-inflammatory,anti-oxidant and other medical functions.In this research,the polysaccharides were extracted with water at 80℃from dewaxed Lobariakoor kauae Yoshim.The protein in the obtained polysaccharides was removed by the treatment of trichloroacetic acid.Then the polysaccharides were fractionated by the graded ethanol precipitation and diethyl-aminoethanol(DEAE)-cellulose-52 chromatography,four(P 15,P 30,P 50 and P 70)and five(Z 1,Z 2,Z 3,Z 4 and Z 5)polysaccharide components were obtained,respectively.The sugar composition,structural properties of nine polysaccharide fractions were characterized by the high-performance anion exchange chromatography and Fourier transform infrared spectroscopy(FT-IR).The results showed that the main monosaccharide components were arabinose,galactose,glucose,mannose and xylose.The mannose was the predominant sugar composition,followed by glucose and galactose.The FT-IR results showed that the characteristic polysaccharides peaks were 3 417,2 911,1 659,1 400,1 026 and 831 cm^-1.The infrared spectra of polysaccharides had the same contour and the structure of the polysaccharides were similar.The intensities of peaks were slightly different,which made contents of the acetyl and uronic acid groups slightly different.The antioxidant activities of 9 polysaccharides was obtained by the ethanol fractional precipitation and the DEAE-52 cellulose column chromatography was studied in vitro.The results showed that the polysaccharides had good ability to scavenge 2,2-diphenyl-1-picrylhydrazyl(DPPH)free radicals and total reducing ability.Among them,the polysaccharide fraction precipitated by 50%ethanol had the strongest scavenging DPPH free radicalability,with a scavenging rate of 80.10%.The polysaccharide fractions precipitated by 15%ethanol had the strongest reducing ability,and its absorbance was up to 0.74.In addition,among the five polysaccharides fractionated by column chromatography,the absorbance of Z 5 was significantly higher than that of the other four types.It can be seen that Z 5 had the strongest antioxidant activity,which was consistent with the results of the DPPH.
作者
汪小君
岳盼盼
杨子颖
熊金衫
孙玲玲
彭锋
WANG Xiaojun;YUE Panpan;YANG Ziying;XIONG Jinshan;SUN Lingling;PENG Feng(College of Materials Science and Technology,Beijing Key Laboratory of Forest Biomass Chemistry,Beijing Forestry University,Beijing 100083,China)
出处
《林业工程学报》
CSCD
北大核心
2019年第4期71-77,共7页
Journal of Forestry Engineering
基金
国家自然科学基金(31470417)
北京林业大学大学生创新训练项目(S201710022048)
伽蓝(集团)股份有限公司合作项目(YFZX-201803-0320)
关键词
老龙皮
多糖
分级沉淀
结构鉴定
抗氧化活性
Lobariakoor kauae Yoshim
polysaccharides
fractional precipitation
structural characteristics
antioxidant activity
