为充分开发柚子产业，进一步提高金柚幼果的利用率，本文以金柚幼果为原料，采用超声辅助酶法提取出金柚幼果多糖（PFCP），得率为9.12%。通过扫描电镜、粒径仪、气相色谱、红外光谱等对PFCP的结构进行表征，结果表明PFCP表面为光滑的多孔网状结构，粒径为101 μm，分子量为3.31 ku，由鼠李糖、阿拉伯糖、半乳糖、葡萄糖、甘露糖和半乳糖醛酸组成的，摩尔比例为0.056:0.138:0.463:0.059:0.186:0.285，是一种酸性杂多糖，主要由-OH、C=O、C-O、C=C和N-H结构构成，其糖链含有苯环和吡喃环。本研究借助小鼠RAW 264.7巨噬细胞模型，发现PFCP在62.5~1000 μg/mL的浓度范围内对小鼠巨噬细胞无明显毒副作用，能显著提高RAW 264.7巨噬细胞表达NO、TNF-α及IL-6细胞因子的分泌量，在1000 μg/mL浓度时细胞因子的表达量最高，NO为42.87 μM，TNF-α为14759.47 pg/mL，IL-6为62.20 pg/mL，表明PFCP具有较强的免疫活性。该研究可为金柚幼果的开发利用提供一定的研究基础。

In order to develop the pomelo industry and improve the utilization of pomelo fruit, in this study, the crude polysaccharide from pomelo fruitlets (PFCP) was extracted by ultrasound-assisted enzymatic method, with a PFCP yield of 9.12%. Scanning electron microscope analysis, particle size analysis, infrared spectrum analysis, and gas chromatography analysis were used to characterize the structure of PFCP. The results showed that PFCP was a heteropolysaccharide with a molecular weight of 3.31 ku, a particle size of 101 μm, and a porous network of spatial structure. The PFCP was composed of rhamnose, arabinose, galactose, glucose, mannose and galacturonic acid in a molar ratio of 0.056:0.138:0.463:0.059:0.186:0.285 with benzene and pyran rings, in which -OH, C=O, C-O, C=C, and N-H structures were contained. In addition, by RAW 264.7 cells model, PFCP has no significant toxic at the range from 62.5 μg/mL to 1000 μg/mL. In terms of cytokine expression, PFCP can effectively promote the expression of three cytokines: NO, TNF-α, and IL-6 in a dose-dependent manner. Among them, the expression of cytokines was the highest at 1000 μg mL of PFCP, and the expression of NO was 42.87 μM, the secretion of TNF-α was 14759.47 pg/mL, and the expression of IL-6 reached 62.20 pg/mL, indicating that PFCP has immune activity. This study may provide some useful information for the pomelo industry.

广东省基础与应用基础研究基金项目（2019A1515011283）