Study On Chemical Constituents Of Burdock Inflorescence Bracts

Arctium lappa L is a biennal herbaceous plants of Compositae. It is widely distributed in our country and grows at the slopes, fields, roadsides and the edge of the town or bushes. Burdock inflorescence bracts is the shell of the Fructus arctii, and the taste is pungent, bitter or quality of cold. It is a kind of famous traditional chinese medicine to treat cough, wind hot, and Lowering inflammation, it also widely used in the treatment of wind hot cold, lung hot cough, sore throat. Modern pharmacology proved that fructus arctii has the functions of Inhibiting bacterial growth, Inhibiting tumor regeneration, Inhibiting influenza virus, falling blood sugar and another pharmacological activities, so it has a good development prospect in the medicine field.Firstly, soaking the dry Burdock inflorescence bracts in the ethanol, then concentrating the leaching solution and water dispersion, and then extracted with the hexane, ethyl acetate and n-butanol, respectively to get the corresponding solvent extract. As the results, twenty three individual compounds were gainned by using silica gel column chromatography and HPLC methods. The structures are identified based on the physical and chemical properties and spectral data analysis, namely, icosan-1-ol(1), β-sitosterol(2), isofouquierol(3), lupeol(4), 3β-hydroxy-21,22-epoxyursa-20(30)-en(5), 3β,21β-dihydroxyl-20(30)-en-taraxastane(6), oleanolic acid(7), ulaol(8), 4(14)-eucaly puts ene-8α,11-glycol(9), monogynol A(10), arctigenin(11), carthamogenin(12), linoleic acid monoglyceride(13), three linoleic acid glycerides(14), Daucosterol(15), and quercetin(16),(22E)-5,8-two oxygen ergoster ol-6,22-diene-3β alcohol(17), pinoresinol(18), 5-(3,4-dimethoxy-phe nyl)-tetrahydro-pyr an-2-1(19), coffee acid(20), gallic acid(21), chrysoeriol(22), scopoletin(23). Compounds 22, 10,3,5, 6, 8, and 9 were firstly separated from the plant of the genus. Compounds(11, 12, 16, 22, and 23) were scanned for the antioxidant activity by the method of eliminating free radical to DPPH. The result shows compound 12 has antioxidant activity with IC50 = 22.1 μM. At the same time, the antibacterial activity of the hexane, ethyl acetate and n-butanol extract were tested, too. The ethyl acetate extract showed antibacterial activity to Bipolaria maydis, Setosphaeria turcica, Phyllostlcta melongenae Sawada, Fusarium oxysporum.sp.cucumebrium Owen, and Alternatia sonali, haxane extract exhibited activity to Phyllostlcta melongenae Sawada, Botrytis cinerea Pers, Bipolaria maydis, Fusarium oxysporum.sp.cucumebrium Owen, Alternatia sonali, and n-butanol extract was active to Bipolaria maydis, Setosphaeria turcica, Phyllostlcta melongenae Sawada, Fusarium oxysporum.sp.cucumebrium Owen, and Alternatia sonali. The antibacterial activity of these extracts became stronger with the higher concentration.