Study On The Chemical Constituents And Pharmacological Activities Of The Root Of A. Chinensis

Rhododendron molle,also known as Huang Dujuan,Nao Yanghua,is a plant in Rhododendron species of rhododendraceae.Rhododendron molle is a deciduous shrub and grows in 0.5-2 meters high.Rhododendron molle can treat rheumatoid arthritis and bruise injury.They are distributed in Jiangsu,Anhui,Zhejiang,Jiangxi,Fujian,Henan,Hubei,Hunan,Guangdong,Guangxi,Sichuan,Guizhou and Yunnan provinces.Total plant,including flowers,fruits,roots and other parts,contains intoxication toxin,naoyanghua toxin,and andromedotoxin and other components,which make people vomit,diarrhea or spasm when eaten by mistake.Sheep often linger and die after eating,so it was named"Yang Zhizhu".In medicine,Rhododendron molle is used as anesthetics and analgesics,and the whole plant can be used as pesticide.Early studies on the plant have reported that diterpenoids and their glycosides showing certain analgesic effect,which may be the active component of the plant's efficacy.However,the triterpenoids in this plant have not been systematically studied.Therefore,based on the full literature research on the active components of rhododendron family,in this paper,the triterpenoids contained in Rhododendron molle roots are separated and the new skeleton triterpenoids are obtained,trying to reveal the medicinal material basis of this plant.In this study,four different parts were extracted by petroleum ether,dichloromethane,ethyl acetate and methanol.Triterpenoids were found in dichloromethane and ethyl acetate according to the test of mass spectrometry.A total of 65 triterpenoids were isolated from these two parts,and their plane structures were established on the basis of a variety of spectrum analysis(UV,IR,HRESIMS,NMR,etc.),The stereoscopic structures of the compounds were determined by coupling constant,NOESY and single crystal X-ray diffraction.The results show that there are 17 new compounds,of which compound 23 is a new skeleton triterpenoid.Compound 23 forms a new skeleton triterpenoid of 5/5/6/6/6/6-fused ring system through the process of A-ring cleavage,elimination of C-23,rearrangement of C2 and C4,esterification of C3 and C24;Compounds 4,5,26 and 31 are all 7-membered lactone rings formed by C2 and C23 after A-ring oxidation,resulting in new triterpenoids of 7/6/6/6-ring system;compounds 1,24 and 27 are 6/6/6/6-ring compounds of 1-carbon reduction of A-ring cleavage ring;compounds 3 and 25 are compounds of 3-carbon reduction of A-ring cleavage ring,compound 2 and 28 are 6/6/6/6-ring compound with one carbon reduction from C-2 to methyl ester;compound 6 is a new oxidized oleanolane triterpene,29 and 30 are new oxidized Ursane-type triterpenes.GABAA receptor modulators can be used as anesthetics,or in the treatment of anxiety,epilepsy,sleep disorders,mental disorders and other diseases.There are many subtypes of GABAA receptor,among which ?1?2?2 subtype is the most important subtype.The results showed that compounds 2,5,14,33 amd 45 had a positive regulatory effect on ?1?2?2 subtype GABAA receptor.It was found that Rhododendron molle has the regulatory effect of GABAA receptor.GABAA receptor modulators can be used as anesthetics and analgesics,or in the treatment of anxiety,epilepsy,sleep disorders,mental disorders and other diseases.In order to find a new active leading compound with analgesic effect and to further clarify the correlation between the traditional efficacy of Rhododendron molle and its chemical components,the isolated monomers were screened for in vitro activity.There are many subtypes of GABAA receptor,among which ?1?2?2 subtype is the most important subtype.The results showed that compound 2,5,14,33 and 45 had a positive regulatory effect on GABAA receptor of ?1?2?2 subtype.The anti-inflammatory activity of compounds 18,19 and 47 was screened by LPS induced TNF-? production model of mouse peritoneal macrophages.The results showed that some triterpenoids in Rhododendron molle had positive regulatory effects on GABAA receptor of ?1?2?2 subtype and anti-inflammatory effects,which was consistent with the traditional effects of anesthesia and analgesia of Rhododendron molle,and provided an important clue for the discovery of more comprehensive effective substances and precursors of Rhododendron molle.