Phytochemical Study Of Eremostachys Moluccelloides Bunge

Eremostachys moluccelloids Bunge is a member of the family Lamiaceae.It is about 25-30 cm tall which root and neck are covered with long hairy nodular white pubescence.Flowers are white,yellow-white to yellow,calyx tubular bell-shaped,flowering from June to July.Mainly distributed in West and Central Asia,including Iran,Afghanistan and other countries.It is distributed in Xinjiang province of China which born in gravelly sandy Gobi arid land.The genus Eremostachys Bunge(Lamiaceae),comprises about 60 species occurring mainly in West and Central Asia.Phytochemical investigations on a few species of Eremostachys revealed the presence of coumarins,flavonoids,phenyl ethanoid glycosides,iridoid glycosides and monoterpene glycosides.The methanol extracts of the plant were extracted with four different polarity solvents: n-hexane,dichloromethane,n-butanol and water.Due to the non-polar of n-hexane fraction,the compounds are mainly volatile oil,and in recent years,the study of the volatile oil compounds has been more extensive.However,the polarities of dichloromethane fraction and n-butanol fraction are in the medium,which contain a large number of small molecular compounds,and it has not been studied much before.Therefore,this study chose these two fractions to separate and purify the chemical constituents and identify their structures.Dichloromethane fraction was firstly separated by TLC and silica gel column chromatography.The selection of eluent was basically the same as that of developing agent in TLC and slowly increased the polarity of the eluent,so that different polar compounds can be fully eluted.According to the difference of molecular weight,the gel column chromatography is used to separate the components.The reversed phase prepare high performance liquid chromatography can be used to separate the components in methanol,acetonitrile and water.Finally,the pure compounds were obtained.However,the polarity of components extracted by n-butanol is larger than that of dichloromethane fraction compounds.Firstly,HP-20 macroporous resin column was used to roughly separate,and the eluents are separated by pure water,25% methanol-water,50% methanol-water,75% methanol-water and 100% methanol.The components can be divided into five parts according to their polarity.The components are mainly separated and purified by the preparation of RP-HPLC,and finally different pure compounds are obtained.Phytochemical investigation of the methanol extract from the aerial part of Eremostachys moluccelloides Bunge(Lamiaceae)from Armenia led to the isolation of18 compounds which are identified as luteolin-7-O-β-glucoside(1),verbascoside(2),chlorogenic acid(3),echinacoside(4),luteolin7-O-(6??-O-β-D-a-piofuranosyl)-β-D-glucopyranoside(5),apigenin-7-O-β-glucoside(6),p-coumaric acid(7),vanillic acid(8),apigenin-7-O-(6′′-E-p-coumaroyl)-β-d-glucopyranosidel(9),apigenin 7-O-(3 ",6"-E-p-dicoumaroyl)-β-glucoside(10),lamalbide(11),6β-h-ydr-oxy-7-epi-loganin(12),phloyoside II(13),5-hydroxy-3’,4’,7-trimethoxyflavone(14),loliolide(15)and5-Hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one(16),14-hydroxyabieta-8,11,13-triene-18-oic-12-carboxy-13-(hydroxymethyl)-lactone(17),2β,14-dihydroxyabieta-8,11,13-triene-11-carbaldehyde-12-carbo-xy-13-(hydroxymeth yl)-lactone(18).The structures were elucidated on the basisof 1D and 2D NMR spectroscopy,UV,MS and by comparison with reported compounds in previous literature.Among them,compounds 1-10,13-18 were obtained from this species for the first time.Compounds 3,4,7,8,10,14-18 have not been isolated previously from any species within the genus Eremostachys.The chemotaxonomic significance of the isolated compounds is discussed.While most of these compounds are well known and widely distributed,the two diterpenes(17 and 18)are noteworthy as this is only the second report of compounds having this tetracyclic skeleton.The narrow,known distribution,to date,of this tetracyclic skeleton suggests that it may be useful as a chemotaxonomic marker for this subfamily,if not for the Lamiaceae as a whole.In previous investigations,the cytotoxic activities against tumor cell lines(MCF-7,Hep G2)of compounds 5,9,10,11,12,13,17,18 from E.molluceloides have not been studied,encouraging us to evaluate the potential cytotoxic activities of these compounds.Therefore,their cytotoxic activities against the MCF-7 and Hep G2 tumor cell lines were evaluated using the CCK8 assay with doxorubicin used as positive control.Compound 12 displayed weak cytotoxic activity against the Hep G2 tumor cell line and compound 18 showed weak cytotoxic activity against the MCF-7 tumor cell line.And other compounds didn’t show obvious cytotoxic activity against two tumor cell lines.