Biotechnological Institute of Chinese Materia Medica and ‡Department of Pharmacology, Jinan University , 601 Huangpu Avenue West, Guangzhou 510632, China .
J Agric Food Chem. 2014 Jan 29;62(4):902-11. doi: 10.1021/jf404752c. Epub 2014 Jan 16.
A novel polysaccharide (LCP50W) with a molecular weight of 4.72 × 10(4) Da was isolated from the pulp tissues of Litchi chinensis . The chemical structure of LCP50W was characterized using physicochemical and instrumental analyses. The results indicated that the main chain of LCP50W consisted of (1→3)-linked β-L-rhamnopyranosyl, (1→6)-linked α-D-glucopyranosyl, and (1→2,6)-linked α-D-glucopyranosyl residues, which branched at O-6. The three branches consisted of (1→2)-linked α-L-rhamnopyranosyl, (1→3)-linked α-D-galactopyranosyl, and (1→3)-linked α-L-mannopyranosyl residues, terminated with (1→)-linked α-L-arabinopyranosyl residues, respectively. The in vitro immunomodulatory assay revealed that LCP50W promoted the proliferation of mouse splenocytes and enhanced the cytotoxicity of NK cells. LCP50W boosted the secretion of Th1 cytokine IFN-γ while it inhibited the secretion of Th2 cytokine IL-4; it also enhanced the expression of T-bet while it inhibited the expression of GATA-3. Additionally, LCP50W promoted the development of cell cycle toward the S phase.
从荔枝果肉组织中分离得到一种分子量为 4.72×10(4)Da 的新型多糖（LCP50W）。采用物理化学和仪器分析方法对 LCP50W 的化学结构进行了表征。结果表明，LCP50W 的主链由（1→3）-β-L-鼠李吡喃糖基、（1→6）-α-D-吡喃葡萄糖基和（1→2,6）-α-D-吡喃葡萄糖基残基组成，这些残基在 O-6 处分支。三个支链分别由（1→2）-α-L-鼠李吡喃糖基、（1→3）-α-D-半乳糖吡喃糖基和（1→3）-α-L-甘露吡喃糖基残基组成，分别以（1→）-α-L-阿拉伯吡喃糖基残基为末端。体外免疫调节试验表明，LCP50W 促进了小鼠脾细胞的增殖，并增强了 NK 细胞的细胞毒性。LCP50W 促进了 Th1 细胞因子 IFN-γ的分泌，同时抑制了 Th2 细胞因子 IL-4 的分泌；它还增强了 T-bet 的表达，同时抑制了 GATA-3 的表达。此外，LCP50W 促进了细胞周期向 S 期的发展。
