3-O-Methylquercetin

3-O-Methylquercetin is an inhibitor of cAMP and CGMP-phosphodiesterase (PDE) with IC₅₀ at 13.8 μM and 14.3 μM, respectively. 3-O-Methylquercetin is an inhibitor of β-secretase with an IC₅₀ of 6.5 μM. 3-O-Methylquercetin has a neuroprotective effect against neuronal death caused by oxidative damage. 3-O-Methylquercetin has strong antiviral activity against poliovirus, coxsackie virus and human rhinovirus. 3-O-Methylquercetin has anti-inflammatory and trachea-relaxing effects and can be used in the study of inflammatory diseases and asthma^{[1][2][3][4][5][6]}. In Vitro:3-O-Methylquercetin (1-10 μM; 24 h) inhibits NO production (IC₅₀: 4.23μM) and the expression of iNOS protein and mRNA in a concentration-dependent manner in RAW 264.7 cells treated with LPS (HY-D1056)^[1].
3-O-Methylquercetin (1-30 μM; 15 min) can relax the trachea of guinea pig^[2].
3-o-methylquercetin (1-100 μM；20-24 h) improves the survival rate of rat cortical cells treated with H₂O₂^[3]. In Vivo:3-O-Methylquercetin (3-30 μmol/kg ≈ 0.95-9.5 mg/kg; Intraperitoneal injection; 3 times) shows improvement in airway hyperresponsiveness induced by oobumin (HY-W250978)^[4].