Chemical Constituents From Two Alangium And Two Liparis Species And Biological Screening For Anti-inflammatory And Antibacterial Activities

Exploring bioactive natural products and elucidating their pharmacological basis,has always been the main research task of natural medicinal chemistry.Through early screening of anti-inflammatory activity from the medicinal plant extractive library and intensive literature research,we selected the genus Alangium and Liparis as our research objects with the purpose of discovering chemical components with anti-inflammatory and anti-bacterial properties.Also,the chemical constituents and bioactivities of these two genera were reviewed before our research was conducted.Four species from the above two genera(Alangium alpinum,Alangium kurzii Craib var.Laxifolium,Liparis regnieri Finet and Liparis viridiflora(B1.)Lindl.)were selected in this study in order to investigate their chemical composition.Preliminary anti-inflammatory and antibacterial activity screenings towards the isolated monomeric compounds were performed subsequently.1.Study on Chemical Constituents of Two Species of Genus AlangiumA variety of modern separation and purification techniques(silica gel column chromatography,preparative thin layer chromatography,MCI column chromatography,Sephadex LH-20 gel column chromatography,preparative HPLC,etc.)were applied on the isolation of A.alpinum and A.kurzii.And a series of analytical methods(ESI-MS,EI-MS,IR,ID and 2D NMR,CD,ICP-AES and XRD,etc.)were used to characterize the structures of these isolates.A total of 120 monomeric compounds were isolated from these two species,and 110 of them were identified.The types of these compounds included cadinane sesquiterpenes,cadinane sesquiterpene alkaloids,lignans and their glycosides and phenolic glycosides,etc.A total of thirteen new compounds were identified,namely cadinane sesquiterpene alkaloid(GS-2),cadinane sesquiterpene alkaloid metal complex(GS-la),arylnaphthalenelignan glycosides(SY-1～SY-4),tetrahydrofuranlignan glucosides(SY-9,SY-10),benzofuranlignan glycosides(SY-19,SY-20)and neolignan glucosides(GS-16,GS-17).Among them,as a new cadinane sesquiterpenoid alkaloid,GS-2 and chemical components of its type were discovered from nature for the first time.Additionally,the phenonmenon that GS-1 coordinated with metal ions to form metal complex as crystals was also very rare.GS-1 was worth further study for its potential property as metal chelators.2.Study on Chemical Constituents of Two Species of Genus LiparisA combination of modern separation and purification techniques were used to separate chemical components of L.regnieri and L.viridiflora.The monomer compounds were characterized by means of various analytical methods.A total of 90 monomeric compounds were isolated from these two species,and 80 of them were identified.The types of the compounds included benzoic acid derivatives,phenanthrenes,biphenanthrenes and phenanthrene glycosides,etc.A total of fifteen new compounds were identified namely phenanthrenes(YR-1,YR-2,YR-4～YR-9),biphenanthrene(YR-39),phenanthrene glycosides(YR-41,YR-42),and other classes(YR-49～YR-52).Biphenanthrenes was a rare kind of chemical composition in nature and for the first time they were discovered in genus Liparis.3.Anti-inflammatory and antibacterial activities screening of the monomer compoundsIn this study,160 compounds isolated from the four plants were screened for anti-inflammatory and antibacterial activities.The results showed that phenanthrenes possessed significant anti-inflammatory activities.And dimeric phenanthrenes were found to exhibit more prominent activities than monomeric phenanthrenes.Based on the structural characteristics of these phenanthrenes and biphenanthrenes,we summarized their structure-activity relationship,which is of great importance for the development of anti-inflammatory lead compounds.In summation,chemical components with anti-inflammatory and antibacterial effects from these four plants will provide an important scientific basis for the rational development and utilization of genus Alangium and Liparis and provide a new direction for the seek and discovery of new anti-inflammatory and antibacterial agents.