New Isopropyl Chromone and Flavanone Glucoside Compounds from the Leaves of <i>Syzygium cerasiforme</i> (Blume) Merr. & L.M.Perry and Their Inhibition of Nitric Oxide Production
Bui Hai Ninh, Dương Thị Dung, Bùi Hữu Tài, Phạm Hải Yến, Nguyễn Xuân Nhiệm, Truong Thi Thu Hien, Đỗ Thị Trang, Nguyễn Văn Tuyên, Anh Tuấn Lê, Hoai Thi Nguyen, Phan Văn Kiệm
Abstract
Abstract A new isopropyl chromone ( 1 ) and a new flavanone glucoside ( 2 ) together with eleven known compounds ( 3–13 ) were isolated from the leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry. Their structures were elucidated as 5,7‐dihydroxy‐2‐isopropyl‐6,8‐dimethyl‐4 H ‐chromen‐4‐one ( 1 ), 5,7‐dihydroxyflavanone 7 ‐O‐β‐ D‐(6′′‐ O ‐galloylglucopyranoside) ( 2 ), strobopinin ( 3 ), demethoxymatteucinol ( 4 ), pinocembrin‐7 ‐O‐β‐ D‐glucopyranoside ( 5 ), (2 S )‐hydroxynaringenin‐7 ‐O‐β‐ D‐glucopyranoside ( 6 ), afzelin ( 7 ), quercetin ( 8 ), kaplanin ( 9 ), endoperoxide G3 ( 10 ), grasshopper ( 11 ), vomifoliol ( 12 ), litseagermacrane ( 13 ) by the analysis of HR‐ESI‐MS, NMR, and CD spectral data. Compounds 1 , 2 , 5 , 6 and 10 inhibited NO production on LPS‐activated RAW264.7 cells with IC 50 values of 12.28±1.15, 8.52±1.62, 7.68±0.87, 9.67±0.57, and 6.69±0.34 μM, respectively, while the IC 50 values of the other compounds ranging from 33.38±0.78 to 86.51±2.98 μM, compared to that of the positive control, N G ‐monomethyl‐L‐arginine acetate (L‐NMMA) with an IC 50 value of 32.50±1.00 μM.