中文摘要：

通过分离纯化及改性得到橘皮素和5-去甲氧基橘皮素,并研究其对人体肝星状细胞株LX-2的抑制作用。通过无水乙醇提取、氯仿萃取从陈皮中得到多甲基黄酮混合物,再以不同浓度的乙酸乙酯和石油醚的混合液为洗脱剂,采用硅胶柱层析分离纯化多甲基黄酮混合物,得到橘皮素纯品。将橘皮素置于盐酸乙醇溶液中回流,对所得产物进行纯化即可得5-去甲氧基橘皮素,采用质谱和核磁共振谱进行结构确证。利用人体肝星状细胞株LX-2细胞作为工具细胞,研究其生物活性。结果表明,5-去甲氧基橘皮素在12.5μmol/L条件下对人肝星状细胞株LX-2的抑制率即可达到50%,而橘皮素需要在近150μmol/L条件下才能达到50%的抑制率,即改性后的橘皮素对人体肝细胞的抑制有效率增加了10倍以上。

英文摘要：

An efficient and large-scale isolation method for tangeretin from Chen-Pi（aged tangerine peels） has been developed successfully. The transformation of tangeretin to 5-demethyltangeretin was performed in acidified alcohol solution with high conversion efficiency. The structures of both isolated tangeretin and 5-demethyltangeretin were confirmed by MS and 1H NMR. Both compounds exhibited strong inhibitory activity against LX-2 human hepatic stellate cells, with an IC50 of 150 μmol/L for tangeretin and 12.5 μmol/L for 5-demethyltangeretin, indicating the increased potency via the conversion from tangeretin to 5-demethyltangeretin.