Studies On The Chemical Constituents Of Lonicerae Japonicae Flos And Its Anti-oxidative Activity

Objective:To study the chemical constituents of Lonicerae japonicae flos and its antioxidant activity in vitro,the chemical constituents of the ethanol extract of Lonicerae japonicae flos were studied systematically.The antioxidative activities of different solvent fractions and compounds were tested.Method:According to the traditional medicinal habits,Lonicerae japonicae flos was extracted with 80%EtOH at room temperature.The combined extract was concentrated in vacuo to yield a residue,which was suspended in H2O,partitioned successively with petroleum ether(60-90℃),CH2Cl2,EtOAc and n-BuOH to afford different solvent fractions.The compounds were isolated and purified by silica gel column chromatography,Sephadex LH-20 column chromatography,polyamide column chromatography,MCI Gel CHP-20,D101 macroporous adsorption resin and recrystallization.The structures were elucidated by the physical and chemical properties,MS,1H-NMR and 13C-NMR spectroscopy.The antioxidant activities of Lonicerae japonicae flos extracts were evaluated by two methods:Oxidative Damage Cell Model of A549 Cells Induced by Hydrogen Peroxide(H2O2)and thin layer chromatography-biosynthesis technique.The antioxidant activities of monomer compounds isolated from Lonicerae japonicae flos were evaluated by thin layer chromatography-biosynthesis technique.Results:Twenty-four compounds were isolated and identified as:myo-inositol(1),8-heptadecanol(2),1-tridecanol(3),β-sitosterol(4),benzoic acid(5),5-hydroxy-7,3’,4’-trimethoxyflavone(6),5,7,4’-hydroxy-3’-methoxyflavone(7),Nortirucallane A(8),isorhamnetin(9),Tetrapedic acid B(10),tricin(11),8,16-dihydroxyp palmitic acid(12),hydnocarpin D(13),6,7,10-trihydroxy-8-octadecenoic acid(14),methoxyhydnocarpin-D(15),β-daucosterol(16),luteolin-7-O-β-D-galactoside(17),caffeic acid methyl ester(18),caffeic acid(19),apigenin(20),luteolin(21),Ochnaflavone(22),kaempferol(23)quercetin(24).The antioxidant activities of ethanol extract,petroleum ether extraction,methylene chloride extraction,ethyl acetate extraction and n-butanol extraction were detected by Oxidative Damage Cell Model of A549 Cells Induced by Hydrogen Peroxide(H2O2).In particular,the antioxidant cure rates of the petroleum ether extraction and n-butanol extraction were more than 50%.Direct TLC-bio-autoradiography showed that the extraction of Lonicerae japonicae flos had good anti-oxidative effect in addition to aqueous extract of dregs.Direct TLC-bio-autoradiography showed that compounds with antioxidant activity were:benzoic acid(5),5-hydroxy-7,3’,4-trimethoxyflavone(6),5,7,4-hydroxy-3 ’-methoxyflavone(7),isorhamnetin(9),tricin(11),hydnocarpin D(13),6,7,10-trihydroxy-8-octadecenoic acid(14),methoxyhydnocarpin-D(15),luteolin-7-O-β-D-galactoside(17),caffeic acid methyl ester(18),caffeic acid(19),apigenin(20),luteolin(21),Ochnaflavone(22),kaempferol(23)quercetin(24).Conclusion:Compound 8 is a new tirucallane-type nortriterpenoid.Compounds 2,3,5,9,10,12,14 and 15 were isolated from the genus of Lonicera for the first time.