Bacterial neuraminidase inhibitory effects of prenylated isoflavones from roots of Flemingia philippinensis.
Bacterial neuraminidase (NA) is one of the key enzymes involved in pathogenesis of inflammation during infection. The organic extract of the roots of Flemingia philippinensis showed high bacterial NA inhibitory activity with an IC50 of around 5μg/mL. Activity-guided separation of the methanol extract yielded nine prenylated isoflavones together with the novel species isoflavone (2) which was given the name flemingsin. Isolated prenylated isoflavones (1-9) were evaluated for NA inhibition and their IC50 values were determined to range between 0.30 and 56.8μM. The most potent inhibitor 4 (IC50=300nM, Ki=130nM) features a catechol motif in the B-ring and a furan in the A-ring. Structure-activity analysis also showed a 4-hydroxyl group within the B-ring was essential for NA inhibitory activity, because isoflavone (9) having protected 4-hydroxyl group was much less potent than its hydroxylated counterpart. All neuraminidase compounds screened were found to be reversible noncompetitive inhibitors. Furthermore, the most active NA inhibitors (1-9) were proven to be present in the native roots in high quantities by HPLC and LC-DAD-ESI/MS.
Division of Applied Life Science (BK21 plus), IALS, Graduate School of Gyeongsang National University, Jinju 660-701, Republic of Korea.
Yan
Y
Wang
Marcus J
MJ
Curtis-Long
Heung Joo
HJ
Yuk
Dae Wook
DW
Kim
Xue Fei
XF
Tan
Ki Hun
KH
Park
D001419:Bacteria / Q000201:enzymology; D003016:Clostridium perfringens / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D007887:Fabaceae / Q000737:chemistry* / Q000378:metabolism; D007529:Isoflavones / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D009439:Neuraminidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D054876:Prenylation; D011485:Protein Binding; D013329:Structure-Activity Relationship
D004791:Enzyme Inhibitors; D007529:Isoflavones; C516713:auriculasin; D009439:Neuraminidase
Flemingia philippinensis; Flemingsin; Neuraminidase; Prenylated isoflavone