文摘
Four new 8,8鈥?7,2鈥?lignans, (+)-ovafolinin B-9鈥?O-尾-d-glucopyranoside (1), (鈭?-ovafolinin B-9鈥?O-尾-d-glucopyranoside (2), (+)-ovafolinin E-9鈥?O-尾-d-glucopyranoside (3), and (鈭?-ovafolinin E-9鈥?O-尾-d-glucopyranoside (4), two neolignans, eusiderin N (5) and (7S,8R)-3,5,5鈥?trimethoxy-4鈥?7-epoxy-8,3鈥?neolignan-9,9鈥?diol-4-O-尾-d-xylopyranoside (6), and two new chromone glycosides, 5,7-dihydroxy-4H-chromen-4-one-3-O-尾-d-glucopyranoside (7) and 5,7-dihydroxy-4H-chromen-4-one-3-O-尾-d-xylopyranoside (8), together with 25 known compounds, were isolated from the stems of Eurya japonica. Structural elucidation of compounds 1鈥?b>8 was 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鈥?b>20, and 29 (ED50 23.40 渭M for 1) demonstrated potent antioxidant activity compared to the positive control 伪-tocopherol (ED50 27.21 渭M). On the other hand, compounds 1, 2, 7鈥?b>9, 12鈥?b>20, and 32 showed only weak anti-NO production activity when compared to the positive control quercetin.