Chemical Constituents From The Root Of Nothopanax Davidii And Their Anti-inflammatory Activities In Vitro

Nothopanax davidii is one of the plants of Nothopanax Miq which belongs to the family of Araliaceae.Its barks and roots are used as folk herbs with the functions of dispelling wind dampness,strengthening bones and muscles to treat diseases such as falling injury,rheumatic joint pain and so on.Up to now,several new triterpenoid saponins with anti-inflammatory activity were isolated from the barks and leaves,but the studies on the roots have not been reported.In order to develop and utilize the medicinal plant,the chemical constituents of N.davidii in the root and the anti-inflammatory activity in vitro were systematically studied in this paper.The crude powder of N.davidii roots were extracted with 95%and 75%ethanol at room temperature,and then successively extracted with petroleum ether（PE）,dichloromethane（DCM）,ethyl acetate（Et OAc）and n-butanol（n-Bu OH）to obtain different polar parts.The chemical constituents were isolated and purified by various modern separation methods such as recrystallization,silica gel,Sephadex LH-20,ODS column chromatography and preparative or semi-preparative HPLC,and their structures were identified by 1D and 2D nuclear magnetic resonance spectroscopy(¹H NMR,¹³C NMR,¹H-¹H COSY,HMQC,HMBC,NOESY),ultraviolet spectroscopy,infrared spectroscopy,mass spectrometry and circular dichroism spectrum,as well as physicochemical properties.Eighteen compounds had been isolated from the DCM and Et OAc extraction fraction including seven lignans,eight triterpenes and triterpenoid saponins,one flavanol,one phenolic and one sterol,and named as:（7S,8R）-dihydro-5′-hydroxy-7-（4-hydroxy-3-methoxyphenyl）-1′-benzofuranpropanol-9-O-β-D-xylopyranoside（1）,（7R,8S）-3’,4,7,9’-tetrahydroxy-3-methoxy-8-O-4’-neolignan-9-O-β-D-xylopyranoside（2）,（7S,8R）-3’,4,7,9-tetrahydroxy-3-methoxy-8-O-4’-neolignan-9’-O-α-L-rhamnopyranoside（3）,Lyoniside（4）,Nudiposide（5）,（+）-Isolariciresinol-9-O-β-D-xylopyranoside（6）,（-）-Isolariciresinol-9-O-β-D-xylopyranoside（7）,kaji-ichigoside F₁（8）,Rosamultin（9）,Arjunetin（10）,Niga-ichigoside F₂（11）,euscaphic acid（12）,myrianthic acid（13）,trans-3-O-p-hydroxycinnamoyl ursolic acid（14）,2-oxopomolic acid（15）,protocatechuic acid（16）,Epicatechin（17）,β-sitosterol（18）.Among them,compound 1 was a new compound,the absolute configuration of compound 2 was confirmed for the first time,all of which were isolated from this plant for the first time and compounds 1-15 and 17 were firstly isolated from Nothopanax Miq.The anti-inflammatory activities of the isolated lignans,triterpenes and triterpenoid saponins were preliminarily predicted by Discovery Studio software using molecular docking technology with nitric oxide synthase（i NOS）as the target protein.The cytotoxicity was determined by MTT method.The nitric oxide（NO）production was measured by the Griess method to evaluated the anti-inflammatory activities on RAW264.7 cells inflammation model induced by lipopolysaccharide（LPS）.The results showed that compound 1-7 had high docking scores with i NOS,a protein related to inflammatory pathway,and had no significant cytotoxicity to RAW264.7 cells when the dose was less than 100μM.Compared with the model group,compound 1-4 significantly inhibited NO production at the dose of 100μM,with an inhibition rate of 13.66%（*P<0.05）,23.95%（**P<0.01）,20.79%（**P<0.01）,28.07%（***P<0.001）,respectively,showing certain anti-inflammatory potential in vitro.Compounds5-7 showed no significant inhibitory effect on inflammation.