Itosides J−N from Itoa orientalis and Structure−Anti-COX-2 Activity Relationship of Phenolic Glycosides

Two new phenolic glycosides, itosides J (1) and K (2), two new cylcohexenoyl glycosides, itosides L (3) and M (4), a new flavone glycoside, itoside N (5), and echitin (6) were isolated from the extract of the bark, twigs, and leaves of Itoa orientalis, together with 22 known compounds. The structures were elucidated by means of UV, IR, MS, and NMR techniques, and the relative configuration of compound 3 was confirmed by X-ray crystallography. NMR data for 6 are reported for the first time. Compounds 1, 3, 5, and phenolic glycosides 7−22 were also assayed for anti-inflammatory activity against COX-2. Compounds 8, 10, 12−14, 16, 19, 24, 26, and 27 showed significant inhibitory effects, with inhibitory rates of 49.7−85.3% at 10 µM.