黄大茶多糖的结构表征及其对3T3-L1前脂肪细胞分化的抑制作用

徐珊; 谢海; 李敏妮; 马妍; 葛慧芳; 李大祥; 谢忠稳; 王红燕

doi:10.13386/j.issn1002-0306.2024040448

黄大茶多糖的结构表征及其对3T3-L1前脂肪细胞分化的抑制作用

Structural Characterization of Large Yellow Tea Polysaccharides and Its Inhibitory Effects on the Differentiation of 3T3-L1 Preadipocytes

摘要

摘要: 本文探究黄大茶多糖的结构特征和降脂活性，为夏秋茶资源的开发利用提供依据。以霍山黄大茶为试验材料提取黄大茶多糖，对其结构进行表征，分别采用高效液相凝胶渗透色谱（High-performance gel-permeation chromatography, HPGPC）、离子色谱（Ion chromatography, IC）、气质联用色谱（Gas chromatography-mass spectrometry, GC-MS）、傅里叶红外光谱（Fourier transform infrared spectrometer, FTIR）、扫描电镜（Scanning electron microscope, SEM）等分析方法测定黄大茶多糖的纯度、分子质量、单糖组成、化学键组成以及糖苷键结构；同时基于3T3-L1前脂肪细胞构建成熟脂肪细胞分化模型，研究黄大茶多糖干预对3T3-L1细胞分化和脂滴累积的影响。结果表明，黄大茶多糖经水提醇沉以及DE-52纤维素阴离子交换层析柱和Sephadex G-100凝胶柱纯化分离获得LYP-W1组分，HPGPC、IC和GC-MS分析结果显示，LYP-W1的分子量为1.25×10⁵ Da，单糖组成为Ara:Rha:Gal:Glc:Man:GalA:GlcA为22.22:8.20:27.59:14.88:5.90:4.09，糖苷键主要由Rhap-(→1、 Araf-(1→、→2)-Rhap-(1→、Glcp-(1→、GlcpA-(1→、Galp-(→1、→5)-Araf-(1→、→2,4)-Rhap-(1→、→4)-Galp-(→1、→4)-GalpA-(1→、→4)-Glcp-(1→、→3,4)-Manp-(1→、→3,6)-Galp-(1→等连接方式构成。FTIR结合SEM分析结果显示，LYP-W1中具有β-型吡喃糖环，表面光滑致密，呈不规则片层薄膜状分布。细胞实验结果显示，LYP-W1在50~200 μg/mL浓度范围内呈剂量依赖性显著抑制3T3-L1细胞的分化并降低其脂质沉积（P<0.05），表明黄大茶多糖具有天然降脂的潜力。本研究可为其它茶多糖的提取、纯化及生物活性研究提供参考。

Abstract: To provide a basis for the development and utilization of summer and autumn tea resources, the structural characteristics and lipid-lowering activity of polysaccharides from large-leaf yellow tea were investigated. The polysaccharides were extracted from Huoshan large-leaf yellow tea, which structural characteristics including purity, molecular weight, monosaccharide composition, functional groups and glycosidic bond types were characterized by high performance gel permeation chromatography (HPGPC), ion chromatography (IC), gas chromatography–mass spectrometry (GC-MS), fourier transform infrared spectrometer (FTIR), and scanning electron microscope (SEM). Concurrently, a mature adipocyte differentiation model was established using 3T3-L1 pre-adipocytes to investigate the effects of large-leaf yellow tea polysaccharide intervention on the differentiation and lipid droplet accumulation in 3T3-L1 cells. A homogeneous polysaccharide fraction (LYP-W1) was obtained from large-leaf yellow tea by water extraction, ethanol precipitation, and purification using DE-52 cellulose and Sephadex G-100 chromatography. Structure analysis indicated that LYP-W1 was composed of Ara:Rha:Gal:Glc:Man:GalA:GlcA=22.22:8.20:27.59:14.88:5.90:4.09 with a molecular weight of 1.25×10⁵ Da, and its repeat unit of the glycosidic linkages were consisted of Rhap-(→1, Araf-(1→, →2)-Rhap-(1→, Glcp-(1→, GlcA-(1→, Galp-(→1, →5)-Araf-(1→, →2,4)-Rhap-(1→, →4)-Galp-(→1,→4)-GalpA-(1→, →4)-Glcp-(1→, →4) →, →3,4)-Manp-(1→, and →3,6)-Galp-(1→. Meanwhile, FTIR and SEM analysis revealed that LYP-W1 contained β-type pyranose rings, with a smooth and compact surface and an irregular lamellar film-like distribution. In addition, LYP-W1 at dose of 50~200 μg/mL can significantly inhibit the differentiation of preadipocytes lipid deposition in 3T3-L1 cells in in a dose-dependent manner, which suggests that LYP-W1 has good lipid-lowering activity（P<0.05）. These results provided a scientific basis for the extraction, purification, and investigation of the biological activities of polysaccharides from other tea sources.