Megastigmane Glycosides from Docynia indica and Their Anti-inflammatory Activities

Using various chromatographic methods, three new megastigmane glycosides, docynicasides A – C (1 – 3) and ten known, (6S,9R)-vomifoliol 9-O-β-d-xylopyranosyl-(1′′→6′)-O-β-d-glucopyranoside (4), hyperin (5), quercitrin (6), quercetin 3-α-l-arabinofuranoside (7), naringenin 7-O-β-d-glucopyranoside (8), phloridzin (9), phloretin 2′-O-β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside (10), pinosylvin 3-O-β-d-glucopyranoside (11), tormentic acid (12), and chlorogenic acid methyl ester (13) were isolated from the fruits of Docynia indica. Their chemical structures were elucidated by physical and chemical methods. All the isolated compounds were evaluated for the inhibitory activity on NO production in LPS-stimulated BV2 cells. As the results, compounds 3 – 5 showed significant inhibitory activity on LPS-stimulated NO production in BV2 cells with the IC₅₀values ranging from 21.0 to 29.3 μm.