截叶铁扫帚Lespedeza cuneata (Dum.Cour.) G. Don为豆科胡枝子属一年生草本植物，在民间具有很高的药用价值，在世界各地均有分布，中药名称夜关门。用于治疗糖尿病、血尿、失眠、营养不良等症。近年来，药理活性研究表明，截叶铁扫帚具有抗氧化、细胞保护、抗炎、抗菌等作用。基于以上研究，本论文对该植物进行了物质基础成分的研究。

本论文对截叶铁扫帚的乙醇提取物采用PRP-512A大孔吸附树脂柱色谱、聚酰胺柱色谱、硅胶柱色谱、凝胶柱色谱、中压液相色谱及高效液相色谱等多种方法进行分离纯化。通过波谱学方法和化学方法等对分离得到的化合物进行鉴定。通过CD法和Mo₂(OAc)₄诱导产生CD法确定新化合物的立体构型。

最终从该植物中得到98个化合物，其中新化合物10个，1-3为新的木脂素苷类化合物，分别命名为(+)-(8S,7′S,8′S)-burselignan-9′-O-β-D-葡萄糖苷，(+)-(8R,7′S,8′R)-异落叶松脂醇-9′-O-β-D-岩藻糖苷，(-)-(8S,7′R,8′R)-甲氧基异落叶松脂醇-9′-O-α-L-鼠李糖苷；4-5为新的苯丙素苷类化合物，分别命名为cuneataside E和cuneataside F；6-9为新的倍半萜苷类化合物，分别命名为cunemegastigmane A-D；10为新的黄酮苷类化合物，命名为6''-?O-?acetylisovitexin。

本文对所分离得到的部分化合物进行了多种体外模型的药理活性筛选，结果显示，化合物2、4、5、6、21与模型组比较具有显著性差异，有一定的肝细胞保护活性；化合物6具有较好的抗氧化活性，其他化合物具有一定的抗氧化活性。

Lespedeza cuneata (Dum.Cours.) G.Don is annual herbaceous plant distributed in many countries, which named ′ye guan men′ in Chinese, is a very important traditional medicine, and has been used in the treatments of diabetes, hematuria, insomnia and malnutrition. According to recent studies, L. cuneata has antioxidation, cell protection, anti-inflammatory effects, and antimicrobial activities. Based on the above research, the studies on the compounds of this plant were taken in this paper.

Ethanolic extract of L. cuneata was subjected to avariety of chromatographic techniques such as macroporous resin, PRP-512A, silica gel, sephadex LH-20, MPLC and HPLC to obtain compounds. The structures were elucidated on the basis of spectrum and chemical methods. The absolute configurations were identificated by CD and Mo₂(OAc)₄ induced CD.

Finally, 98 comounds were isolated, including 10 new compounds.1-3 were new lignin glycosides, namely (+)-(8S,7′S,8′S)-burselignan-9′-O-β-D-glucopyranoside, (+)-(8R,7′S,8′R)-isolariciresinol-9′-O-β-D-fucopyranoside, and (-)-(8S,7′R,8′R)-meth- oxyisoariciresinol-9′-O-α-L-rhamnoside; 4-6 were new phenylpropanoid glycosides, namely cuneataside E and cuneataside F; 6-9 were new glycosides megastigmane derivatives, namely cunemegastigmane A-D; 10 was a new flavonoid glycosides, named 6''-?O-?acetylisovitexin.

In the in vitro assays, compounds 2, 4, 5, 6, 21 exhibited hepatoprotective activities against N-acetyl-p-aminophenol (APAP)-induced toxicity in HepG2 (human hepatocellular liver carcinoma cell line) cells, using the hepatoprotective activity drug bicyclol as the positive control. Compound 6 exhibited moderate antioxidation activities.