Study On The Chemical Constituents And Their Anti-inflammatory Activities From Inula Japonica

Inula japonica Thunb.has been used in Chinese folk medicine for the treatment of bronchitis,nausea,hiccup,excessive sputum and inflammation,it belongs to the genus Inula of family Compositae and distributes in China,Korea,Japan and other region of world.At present,It is reported that many compositions have been identified from I.japonica,mainly included flavonoids,sterols,coumarin and terpenoids,etc.The anti-inflammatory,antibacterial,antihepatitic,antitumor and antioxidant activities from I.japonica have been reported before.Our previous study demonstrated that the anti-inflammatory and anti-asthmatic activities of the flowers extract of I.japonica.In order to search the constituents from I.japonica,we began to study the chemical consitituents from I.japonica by repeated column chromatography,including silica gel,toyopearl HW-40 and preparative HPLC,38 compounds were isolated from 75%EtOH extract of I.japonica.By analysis of IR,MS,1D NMR and 2D NMR spectra,the structures of isolated compounds were identified as follows:1?-hydroxy-3-oxo-11?H-eudesma-4(5)-en-12,8?-olide(1),1-O-?-D-glucopyranosyl-11?H-eudesma-4(5)-en-12,8?-olide(2),1-O-?-D-glucopyranosy1-4,11?H-eudesma-5(6)-en-12,8?-olide(3),1-oxo-4?H-eudesma-5(6),11(13)-dien-12,8?-olide(4),6?-isobutyryloxy-linulicin(5),6a-(2-methylbutyryloxy)linulicin(6),6a-(3-methylvaleryloxy)linulicin(7),1?-hydroxy-8?-acetoxy-3-oxo-eudesma-4(5),11(13)-dien-12-oic acid methyl ester(8),19-O-?-D-glucopyranosyl-16a-hydroxy-17-acetoxy-ent-kauran-19-oic acid(9),ivangustin(10),1?,3a-dihydroxy-eudesma-4(5),11(13)-dien-12,8?-olide(11),(1?,3?,4?,7?,8?,11?)-1,3-dihydroxy eudesm-12,8-lactone(12),1?-hy droxyalantolactone(13),(1 R,4S,5R?R,8R,1 OS)-1,5-dihydroxy-eudesma-11(13)-en-12,8-olide(14),1?-hydroxy-4?,11?H-eudesma-5en-12,8?-olide(15),deacetylinulicin(16),inulicin(17),1,6-0,0-diacetylbritannilactone(18),6a-isobutyryloxy-1-hydroxy-4?H-1,10-secoeudesma-5(10),11(13)-dien-12,88-olide(19),6a-isovaleryLoxy-1-hydroxy-4?H-1,10-secoeudesma-5(10),11(13)-dien-12,8?-olide(20),1?-hydroxy-8?-acetoxy-isocostic acid methyl ester(21),1?-hydroxy-8?-acetoxycostic acid methyl ester(22),16a,17-dihydroxy-ent-kauran-19-oic acid(23),quercetin(24),napetin(25),eupatin(26),spinacetin(27),luteolin(28),taxifolin(29),taraxasterol acetate(30),arnidiol(31),p-hydroxycinnamic acid(32),caffeic acid(33),caffeoyl acetate(34),(6R,7E)-9-hydroxy-4,7-megastigmadien-3-one(35),(3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmen-9-one(36),8,9,10-trihydroxythymol(37),dihydrosyringenin(38).Compound 1?9 are new compounds.Compound 23,29,32,34,36,38 were isolated from the genus Inula for the first time,Compound ??? 10,23,25?27,29,31?36,38 were isolated from this plant for the first time.The anti-inflammatory activities of isolated compounds were examined,including the suppression effects of NO producion in macrophages,inhibition effects of LTC4 synthesis and degranulation in mast cells.In the non-cytotoxic concentrations,we used Griess method to test the suppression effects of LPS-induced NO production in RAW264.7 cells,the results showed that compounds 4,18?20,24 and 28 had strong suppression effects of NO,their IC50 are 3.46 ?M,13.8 ?M,3.11 ?M,1.9 26.5 ?M and 24.5 ?M,respectively.The results of the LTC4 synthesis suppression showed that compounds 14,15,18,20,22,24?29 exhibited potent inhibition effects of LTC4 synthesis in KL-induced mast cells.In addition,compounds 5,24,25,28 revealed potent inhibition activities on degranulation in KL-induced mast cells.To evaluate the anti-inflammatory activities of isolated compounds,including the suppression effects of NO producion,inhibition effects of LTC4 synthesis and degranulation.We found the anti-inflammatory ingredients of I.japonica were sesquiterpenes and flavonoids,and the strongest inhibitory activities were eudesmanes(compounds 18?20)and flavonoids(compounds 24?29).