Liu Xiao, Yang Ming-hua, Wang Xiao-bing, Xie Sai-sai, Li Zhong-rui, Kim Dong-hynu, Park Jun-seong, Kong Ling-yi
State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
Fitoterapia. 2015 Jun;103:136-42. doi: 10.1016/j.fitote.2015.03.011. Epub 2015 Mar 27.
Four new neolignans (1-4), together with two known lignans (5 and 6), were isolated from the root of Paeonia lactiflora. Compounds 1 and 2 were two racemates and were separated by chiral high performance liquid chromatography (HPLC) to give all of the four stereoisomeric forms sharing a common planar structure. Compounds 3 and 4 were two neolignan glycoside diastereomers but interestingly appeared to be enantiomers: they had the extremely similar (1)H and (13)C NMR spectra and had to be solved only by chiral HPLC. Their structures were determined by spectroscopic analysis, including 1D and 2D NMR, HRESIMS and electronic circular dichroism experiments. All compounds were evaluated for their inhibitory effects on β-amyloid aggregation, and the optical pure compound 2b was found to show the optimal Aβ(1-42) aggregation inhibition potency (81.1% at 20 μM). In addition, despite large amount of chemical studies performed on genus Paeonia, the lignans were reported for the first time.
从芍药根中分离得到了4个新的新木脂素（1-4）以及2个已知木脂素（5和6）。化合物1和2为两个外消旋体，通过手性高效液相色谱（HPLC）分离得到了具有相同平面结构的所有4种立体异构体形式。化合物3和4为两个新木脂素糖苷非对映异构体，但有趣的是它们似乎是对映体：它们具有极其相似的氢谱（1H）和碳谱（13C）核磁共振谱，只能通过手性HPLC来区分。通过光谱分析确定了它们的结构，包括一维和二维核磁共振、高分辨电喷雾电离质谱（HRESIMS）以及电子圆二色光谱实验。评估了所有化合物对β-淀粉样蛋白聚集的抑制作用，发现光学纯的化合物2b表现出最佳的Aβ（1-42）聚集抑制活性（20 μM时为81.1%）。此外，尽管对芍药属进行了大量化学研究，但这些木脂素是首次被报道。
