目的 研究玉兰Magnolia denudata叶的木脂素类化学成分。方法 采用硅胶柱色谱、Sephadex LH-20柱色谱以及半制备HPLC等色谱方法进行分离纯化，根据波谱数据鉴定化合物的结构，并采用脂多糖（LPS）诱导的RAW264.7细胞NO生成模型对分离得到的化合物进行抗炎活性筛选。结果 从玉兰叶95%乙醇提取物中分离得到2个四氢呋喃型木脂素和3个苯并呋喃型木脂素，分别鉴定为（7S，7'R，8S，8'S）-3，4，5-三甲氧基-3'，4'-亚甲二氧基-7，7'-环氧木脂烷（1）、蔚瑞昆森（2）、liliflol A（3）、liliflol B（4）和5-methoxyliliflol B（5）。结论 化合物1为新化合物，命名为玉兰木脂素A，化合物5为新天然产物，同时首次报道化合物3～5的¹³C-NMR数据。化合物5对LPS诱导的RAW264.7细胞释放NO具有一定的抑制作用，在50 μmol/L浓度下其抑制率为48.7%。

Objective To study the lignans in the leaves of Magnolia denudata. Methods The constituents were separated and purified by silica gel, Sephadex LH-20 and semi-preparative HPLC. The structures were elucidated on the basis of spectroscopic data analysis. All compounds were evaluated for their inhibitory activity against LPS-activated NO production in RAW 264.7 cell model in vitro. Results Two tetrahydrofuran-type lignans and three dihydrobenzofuran-type lignans were isolated from 95% ethanol extract of M. denudate. Their structures were identified as (7S,7'R,8S,8'S)-3,4,5-trimethoxy-3',4'-methylenedioxy-7,7'-epoxylignan (1), veraguensin (2), liliflol A (3), liliflol B (4) and 5-methoxyliliflol B (5). Conclusion Compound 1 is a new compound and named as magnodatin A. Compound 5 is a new natural product. The ¹³C-NMR spectroscopic data of compounds 3—5 are reported for the first time. Compound 5 exhibited weak inhibitory effect on NO production in LPS-induced macrophages with a inhibiton rate of 48.7% at 50 μmol/L.

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云南省科技厅-昆明医科大学应用基础研究联合专项基金（2019FE001-028，2017FE467-016）；云南省天然药物药理重点实验室开放基金课题（70120030509）；云南省万人计划“教学名师”（宋流东）资助项目