白木乌桕中1个新的木脂素葡萄糖苷

One new lignan glucoside from Neoshirakia japonica

目的研究白木乌桕Neoshirakiajaponica醋酸乙酯提取物中木脂素类化学成分及其抗神经炎症和DPPH自由基清除活性。方法利用多种色谱手段(硅胶、SephadexLH-20、ODS和制备型HPLC等)对醋酸乙酯提取物的化学成分进行分离纯化,再借助现代波谱手段(紫外、红外、核磁、质谱、圆二色谱)和化学方法对其进行结构鉴定,采用脂多糖(LPS)刺激的BV-2小胶质细胞释放NO模型分析化合物对NO产生的抑制作用,评价其潜在的抗神经炎症活性;另外以维生素C(Vc)作为阳性对照分析化合物对DPPH自由基的清除能力。结果首次从白木乌桕醋酸乙酯提取物中分离得到2个木脂素葡萄糖苷类化合物,分别鉴定为(-)-松脂醇4-O-[6-O-(E)-咖啡酰基]-β-D-吡喃葡萄糖苷(1)和(+)-松脂醇4-O-[6-O-(E)-咖啡酰基]-β-D-吡喃葡萄糖苷(2);DPPH自由基清除活性实验结果显示,化合物2对DPPH自由基清除的半数抑制浓度(IC50)为38.1μmol/L。结论化合物1为新化合物,命名为白木乌桕糖苷A。与阳性对照Vc相比,化合物2对DPPH自由基有一定的清除能力。

Objective To study the chemical constituents from the EtOAc extract of Neoshirakia japonica and their anti-neuroinflammatory and DPPH-radical scavenging activity. Methods The chemical constituents were isolated and purified by silica gel, Sephadex LH-20, ODS column chromatographies, and semi-preparative HPLC, then their structures were elucidated by extensive modern spectroscopic analyses(UV, IR, NMR, HRESIMS, and ECD) and chemical methods. All compounds were evaluated for their anti-neuroinflammatory activities by inhibiting the nitric oxide(NO) production in lipopolysaccharide(LPS)-activated murine BV-2 microglial cells and their DPPH-radical scavenging abilities with the positive control vitamin C. Results Two lignan glucosides were isolated from the EtOAc extract of N. japonica and identified as(-)-pinoresinol 4-O-[6-O-(E)-caffeoyl]-β-D-glucopyranoside(1) and(+)-pinoresinol 4-O-[6-O-(E)-caffeoyl]-β-D-glucopyranoside(2). The results of DPPH-radical scavenging activity showed that the IC50 value of compound 2 was 38.1 μmol/L. Conclusion Compound 1 is a new lignan glucoside named as japonicoside A. Compound 2 exhibited moderate DPPH-radical scavenging activity, compared to the positive control Vc(IC50 = 20.7 μmol/L).