食品科学

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提取温度对霍山石斛多糖理化性质及肠道黏膜免疫活性的影响

江贤敏,王正明,潘利华,查学强,罗建平*   

  1. 合肥工业大学食品科学与工程学院,安徽 合肥 230009
  • 出版日期:2017-04-15 发布日期:2017-04-24

Effect of Extraction Temperature on Physicochemical Properties and Intestinal Mucosal Immunomodulating Activity of Polysaccharides from Dendrobium huoshanense

JIANG Xianmin, WANG Zhengming, PAN Lihua, ZHA Xueqiang, LUO Jianping*   

  1. School of Food Science and Engineering, Hefei University of Technology, Hefei 230009, China
  • Online:2017-04-15 Published:2017-04-24

摘要: 目的:研究提取温度对霍山石斛多糖提取量、理化性质以及肠道黏膜免疫活性的影响。方法:在不同提取温度(40、60、80、100 ℃)条件下水提醇沉法提取霍山石斛多糖(Dendrobium huoshanense polysaccharides,DHP),并测定多糖提取量和特性黏度;采用高效液相色谱(high performance liquid chromatography,HPLC)、气相色谱(gas chromatography,GC)、傅里叶变换红外光谱(Fourier transform infrared spectrometry,FTIR)技术分析霍山石斛多糖及其阴离子交换色谱水洗组分和盐洗组分的分子质量分布、单糖组成和特征基团;以体外培养的小鼠小肠Peyer结细胞的培养液对小鼠骨髓细胞增殖作用为指标,测定多糖及其分级组分的肠道黏膜免疫调节活性。结果:DHP的提取量随提取温度的升高而增加,但其特性黏度呈现下降趋势。HPLC分析表明不同温度条件下提取的多糖均由高分子质量(higher molecular weight,HMW)和低分子质量(lower molecular weight,LMW)两种组分所构成,LMW热稳定性好、主要存在于阴离子交换色谱的水洗脱组分(water-eluted fraction,DHPW),HMW热稳定性弱、主要存在于阴离子交换色谱的盐洗脱组分(salt-eluted fraction,DHPS);GC和FTIR分析显示,DHPW主要由呈α-构型的葡萄糖所组成、不含糖醛酸,DHPS主要由呈β-构型的葡萄糖、半乳糖、阿拉伯糖和甘露糖所组成,且含糖醛酸;不同温度提取的DHP及其阴离子交换色谱DHPW和DHPS均表现出肠道黏膜免疫调节活性,且DHPS比DHPW具有更强的肠道黏膜免疫调节活性,但它们的活性均随提取温度的升高而下降。结论:不同提取温度不仅影响DHP的提取量,而且可明显改变DHP的特性黏度、分子质量分布、单糖组成和肠道黏膜免疫调节活性,较高的提取温度在提高DHP提取量的同时显著降低DHP中HMW比例,进而导致多糖肠道黏膜免疫调节活性的下降。

关键词: 霍山石斛, 提取温度, 多糖, 理化性质, 肠道黏膜, 免疫活性

Abstract: Objective: To investigate the effect of extraction temperature on the yield, physicochemical properties and intestinal mucosal immunomodulating activity of polysaccharides extracted from Dendrobium huoshanense. Methods: Four different extraction temperatures including 40, 60, 80 and 100 ℃ were used to investigate the changes in the yield and intrinsic viscosity of Dendrobium huoshanense polysaccharides (DHP) extracted by the water extraction-ethanol precipitation method. High performance liquid chromatography (HPLC), gas chromatography (GC) and Fourier transform infrared spectrometry (FTIR) were used to analyze the molecular weight distribution, monosaccharide compositions and characteristic groups of DHP and its fractions eluted with water and salt solution from DEAE-cellulose anion exchange column. The conditioned medium from Peyer’s patch cells from the small intestine of mice was used to determine the intestinal mucosal immunomodulating activity of DHP and its fractions by observing the proliferation of bone marrow cells of mice. Results: With increasing extraction temperature, the yield of DHP rose and its intrinsic viscosity dropped. HPLC analysis showed that DHP extracted at different temperatures were mainly composed of higher molecular weight fraction (HMW) and lower molecular weight fraction (LMW). LMW, which had better thermal stability, mainly existed in the water-eluted fraction (DHPW) from DEAE-cellulose anion exchange column and HMW, which had weaker thermal stability, mainly existed in the salt-eluted fraction (DHPS). GC and FTIR analysis displayed that DHPW mainly consisted of Glc in α-configuration and DHPS mainly consisted of Glc, Gal, Ara and Man in β-configuration with some uronic acids. All DHPs from different extraction temperatures and the corresponding DHPW and DHPS fractions possessed intestinal mucosal immunomodulating activity and the activity of DHPS was higher than that of DHPW, but their activities decreased significantly with increasing extraction temperature. Conclusion: Extraction temperatures not only influenced the yield of DHP, but also markedly changed its intrinsic viscosity, molecular weight distribution, monosaccharide compositions and immunomodulating activity. Although higher temperature increased the extraction yield of DHP, it significantly decreased the intestinal mucosal immunomodulating activity of DHP because of the reduction in the proportion of HMW in DHP.

Key words: Dendrobium huoshanense, extraction temperature, polysaccharides, physicochemical properties, intestinal mucosa, immunomodulating activities

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