Study On Chemical Components And Activity Screening From Secondary Metabolites Of Platycarya Longipes

Platycarya longipes,belongs to the genus Platycarya of Juglandaceae,is a dominant and constructive species in karst forest ecosystem,which plays a key role in the protection and stability of karst ecosystem.It also has the medicinal value of clearing away heat and toxic materials,promoting blood circulation and removing blood stasis,killing parasites and relieving itching.In recent years,the researches mainly focused on the simulation of the physiological and ecological experiments of drought as well as the field investigation of the P.longipes,however,there are few reports on the secondary metabolites of P.longipes.In this dissertation,the secondary metabolites of P.longipes are studied.And the chemical constituents isolated form this plant are evaluated for their anti-bacterial and anti-tumoractivities.We hope these works will provide experimental basis for futher studies on the chemical composition and potential pharmaceutical values of P.longipes.Besides,it could be helpful to analyze the relationships between chemical components and plant groups from the perspective of chemical taxonomy and the biological protection of the plants in karst forest ecosystem from this genus.In this study,P.longipes was collected from Qiandongnan of Guizhou Province.After the total extract and then extracted by different polar solvents to yield the different polarities.Subsequently,the monomer compound were obtained by comprehensive separation methods,and then the structures of these compounds were elucidated by different spectroscopy methods.In addition,Sulforhodamine B（SRB）colorimetric method was used to test the anti-tumor activity of these compounds in vitro.Additionally,the antibacterial activity of the isolated compounds was tested by the method of punch diffusion based on seven strains.The main results of our study are as follows:1.20 compounds were isolated by repeatedly chromatographic meth ods,among them,15 compounds were identified by spectroscopic metho ds combined with literature data.These compounds including rhoiptelol C（1）,rhoiptelol B（2）,5-hydroxy-7-（4-hydroxy-3-methoxyphenyl）-1-（4-hydroxyphenyl）-3-heptanone（3）,（R）-4-（5-hydroxy-7-（4-hydroxyphenyl）heptyl）-2-methoxy-phenol（4）、5-hydroxymethyl-2-furancarboxaldehyde（5）、1,7-bis（4-hydroxy-3-methoxyphenyl）-3,5-heptanediol（6）、1,7-bis（4-hydroxy-3-methoxyphenyl）-3,5-heptanediol（7）,methyl gallate（8）,qu ercetin-3-O-α-L-rhamnopyranoside（9）,1-（4-hydroxy-3-methoxyphenyl）-7-（4-hydroxyphenyl）-3,5-heptanediol（10）、rel-（3R,5S）-3,5-dihydroxy-1-（4-hydroxy-3-methoxyphenyl）-7-（4-hydroxyphenyl）-heptane（11）,myrice tin-3-O-α-L-rhamnoside（12）,Kaempferol-3-O-α-L-rhamnopyranoside（13）,（7S,8R,7″R,8″R）-4″-hydroxy-3,3″,5,5′-tetramethoxy-4′,7-epoxy-4,8″-o xy-8,3′-sesquineoligna-7″,9,9′,9″-tetrol（14）,（7S,8R,7″S,8″S）-4″-hydroxy-3,3″,5,5′-tetramethoxy-4′,7-epoxy-4,8″-oxy-8,3′-sesquineoligna-7″,9,9′,9″-tetrol（15）.Most of these compounds belongs to diarylheptanoids,and th e others belongs to flavonoids,lignans,phenolic derivatives and lignans.Of which,compounds 2-7 and 9-15 were isolated from P.longipes.for th e first time.2.In the evaluation of anti-tumor activity in vitro,SRB method was used to detect the inhibitory effect of compounds 1,4,7,8,9,10,12 isolated from P.longipes.against human hepatoma SK-Hep-1 cells.The experimental results show that the diarylheptanoid compounds 4 and 7could show some inhibitory activity against the human hepatoma SKHep-1 cell in vitro.Nevertheless,the flavonoid glycosides 9,12 and phenolic derivative 8 didn’t show significant inhibitory activity in vitro.In the in vitro bacteriostatic activity experiment,the antimicrobial activities of compounds 1,3,6,8,9,10 and 12 against drug-resistant Staphylococcus aureus,Salmonella typhimurium,Micrococcus luteus,Shigella sonnei,Escherichia coli,Proteus vulgaris and Candida albicans were tested by punch diffusion method.The results showed that these compounds isolated from P.longipes.did not show significant antibacterial activity against the selected seven strains in vitro.Conclusion: Fifteen compounds,including diarylheptanoids,flavonoids,lignans and phenolic derivatives,were isolated from P.longipes（most of them were isolated from this plant for the first time）.In addition,the antitumor and antibacterial activities were evaluated in vitro,and the results showed that diarylheptanoids had potential antitumor activity.The above findings provide experimental and theoretical data for the chemotaxonomy of P.longipes and the biological protection of karst environment,and provide a reference for the development and utilization of the potential medicinal value of P.longipes.