仙鹤草中木脂素类化学成分的研究

Studies on lignans from Agrimonia pilosa

目的对仙鹤草Agrimonia pilosa的化学成分进行分离和鉴定,并利用去血清损伤的PC12细胞模型筛选化合物的神经保护活性。方法利用80%乙醇对仙鹤草进行提取,再通过大孔吸附树脂、ODS、硅胶、Sephadex LH-20凝胶以及半制备型高效液相等柱色谱方法进行分离,然后根据质谱、核磁、圆二色谱等波谱学数据鉴定化合物的结构。结果从仙鹤草中分离并鉴定了10个木脂素类化合物,分别命名为仙鹤草酸酯(1)、仙鹤草苷A(2)、苦树苷C(3)、长花马先蒿苷B(4)、(7R,8S)-4,7,9,9′-四羟基-3,3′-二甲氧基-8-O-4′-新木脂素-7-O-β-D-葡萄糖苷(5)、(7S,8S)-3-甲氧基-8,4′-氧代新木脂素-3′,4,7,9,9′-五醇(6)、红叶藤苷(7)、(7S,8R)-1-[4-O-(β-D-吡喃葡糖糖基)-3-甲氧基苯基]-2-[4-(3-羟丙基)-2,6-二甲氧基苯氧基]-1,3-丙二醇(8)、密穗马先蒿苷(9)、淫羊藿醇A2(10)。结论化合物1和2为新化合物,其余化合物均为首次从仙鹤草中分离得到。化合物1a和1b为1对互变的葡萄糖端基手性相反的8-O-4′型木脂素酸酯;化合物1在10μmol/L对去血清损伤的PC12神经细胞表现出一定的保护作用。

Objective To investigate the chemical constituents of Agrimonia pilosa and evaluate their neuroprotective activities by PC12 cell model.Methods Firstly,the dried plant of A.pilosa were extracted by 80%ethanol aqueous.Then,the compounds were isolated and purified by a variety of chromatographic techniques including HP-20 macroporous resin,ODS,silica gel,Sephadex LH-20,and semi-preparative HPLC.The structures of the isolates were determined by a combination of HR-ESI-MS,NMR,and ECD spectra.Finally,the neuroprotective activities of isolates were tested.Results Ten lignans were isolated and identified as pilosaneolignan ester(1),pilosaneolignanside A(2),picraquassioside C(3),longifloroside B(4),(7R,8S)-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8,4′-oxyneolignan-7-O-β-D-glucoside(5),(7S,8S)-3-methoxy-8,4′-oxyneoligna-3′,4,7,9,9′-pentol(6),rourinoside(7),(7S,8R)-1-[4-O-(β-D-glucopyranosyl)-3-methoxyphenyl]-2-[4-(3-hydroxy-propyl)-2,6-dimethoxyphenoxy]-1,3-propanediol(8),densispicoside(9),and icariol A2(10).Conclusion The structures of 1 and 2 are new compounds,compounds 3–10 are isolated from A.pilosa for the first time.Notably,compounds 1a and 1b represent a pair of interchangeable 8,4′-oxyneolignan glucose ester with the opposite hemiacetal hydroxy.Compound 1 exhibits the moderate protective effect on injury induced by serum deprivation in PC12 cells at 10μmol/L.