Yang Kuo, Li-Ming, Zhang, Li-Jie, Huang, Hung-Tse, Lin, Zhi-Hu, Liaw, Chia-Ching, Cheng, Hui-Ling, Lee, Kuo-Hsiung, Morris-Natschke, Susan L., Kuo, Yao-Haur, and Ho, Hsiu-O
Four new 8,8′,7,2′-lignans, (+)-ovafolinin B-9′-O-β-d-glucopyranoside (1), (−)-ovafolinin B-9′-O-β-d-glucopyranoside (2), (+)-ovafolinin E-9′-O-β-d-glucopyranoside (3), and (−)-ovafolinin E-9′-O-β-d-glucopyranoside (4), two neolignans, eusiderin N (5) and (7S,8R)-3,5,5′-trimethoxy-4′,7-epoxy-8,3′-neolignan-9,9′-diol-4-O-β-d-xylopyranoside (6), and two new chromone glycosides, 5,7-dihydroxy-4H-chromen-4-one-3-O-β-d-glucopyranoside (7) and 5,7-dihydroxy-4H-chromen-4-one-3-O-β-d-xylopyranoside (8), together with 25 known compounds, were isolated from the stems of Eurya japonica. Structural elucidation of compounds 1–8was established by spectroscopic methods, especially 2D NMR techniques, electronic circular dichroism data, and comparison with reported data. The isolates were evaluated for antioxidant and anti-NO production activities. Compounds 1, 2, 12–20, and 29(ED5023.40 μM for 1) demonstrated potent antioxidant activity compared to the positive control α-tocopherol (ED5027.21 μM). On the other hand, compounds 1, 2, 7–9, 12–20, and 32showed only weak anti-NO production activity when compared to the positive control quercetin.