Chemical constituents from the leaves of Citrus reticulata and their anti-inflammatory activities
AIM To study the chemical constituents from the leaves of Citrus reticulata Blanco and their anti-inflammatory activities.METHODS The 85%ethanol extract from the leaves of C.reticulata was isolated and purified by silica gel,D101 macroporous resin,MCI,ODS and Sephadex LH-20,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The Griess method was used to determine their inhibitory activities on lipopolysaccharide-induced NO production in macrophages RAW 264.7 cells.The mice foot swelling inflammation model induced by carrageenan was established,and the levels of IL-1β,TNF-α were detected.RESULTS Twelve compounds were isolated and identified as nobiletin(1),tangeretin(2),5-demethylinoblitin(3),5,4'-dihydroxy-6,7,8,3'-tetramethoxy flavone(4),5-hydroxy-7,8,3',4'-trimethoxyflavanone(5),3,5,6,7,8,3',4'-heptamethoxyflavanone(6),hesperetin(7),5-hydroxy-6,7,3',4'-tetramethoxyphenone(8),β-balsam alcohol(9),stigmaster-5-en-3β-alcohol(10),p-hydroxybenzaldehyde(11),vanillin(12).Compounds 1,4,6,7,10 and 12 had strong inhibitory activites on NO release in LPS-induced RAW 264.7 cells,and the IC50 values were(25.21±2.10),(37.77±0.50),(38.19±1.58),(21.89±1.73),(43.81±1.18),(47.98±2.55),(41.23±1.11),(43.80±1.43)μmol/mL,respectively.Compounds 2-3 reduced IL-1β and TNF-α levels(P<0.05,P<0.01).CONCLUSION Compounds 6-7,9 are isolated from this plant for the first time.Compounds 1-4,8 exhibit strong in vitro anti-inflammatory activities,and compounds 2-3 exhibit significant in vivo anti-inflammatory activities.
Citrus reticulata Blancoleaveschemical constituentsisolation and identificationanti-inflammatory activities