Studies On The Chemical Constituents And Biological Activities Of Aruncus Sylvester

Aruncus sylvester Kostel.（Rosaceae）is a perennial herb distributed mainly in the northwest of China,Japan,North Korea and Russia.The dried roots of A.sylvester are commonly known as‘Jinmaosanqi’,and have been used in Chinese folk medicine for the treatment of traumatic injury and internal lesion caused by overexertion.At present,there is no systematic research on the chemical constituents and biological activities of A.sylvester at home and abroad.Therefore,based on the previous research,this subject continues to further study the chemical constituents and biological activities of A.sylvester to provide a scientific basis for the clinical application and further development of A.sylvester.The chemical constituents and biological activities of A.sylvester were systematically studied in this study.18 compounds were isolated from the ethanol extract of the roots of A.sylvester Kostel.by solvent extraction,silica gel column chromatography,polyamide column chromatography,Sephadex LH-20 column chromatography,reversed phase medium pressure preparative chromatography,along with high performance liquid chromatography.UV,IR,¹H NMR,¹³C NMR,DEPT,HSQC,HMBC,NOESY,HR-ESI-MS spectra,along with other structure identification methods were used to identify the structures of the isolated compounds.And the structures of 17 compounds were established,including seven phenylpropanoid（caffeic acid（ASE-5）,methyl caffeate（ASE-7）,grayanin（ASE-10）,cis-feruloyl glucose（ASB 50-11a）,trans-feruloyl glucose（ASB 50-11b）,3,4-di-O-（E）-caffeoyl-α-glucopyranoside（ASB50-9a）,3,4-di-O-（E）-caffeoyl-β-glucopyranoside（ASB 50-9b））,seven monoterpenoids（aruncide A（ASB 50-1）,sylvesteroside B（ASB 50-6）,sylvesteroside D（ASB 50-13）,sylvesteroside E（ASB 50-2）,sylvesteroside F（ASB 50-12）,sylvesteroside G（ASB50-5）,sylvesteroside H（ASB 50-10））and three flavonoids（2S-eriodictyol-7-O-β-D glucopyranoside（ASB 50-8a）,2R-eriodictyol-7-O-β-D glucopyranoside（ASB 50-8b）,isorhamnetin-3-O-β-D-glucoside（ASB 50-15））.Among the 17 compounds,ASB 50-9a,ASB 50-9b,ASB 50-6,ASB 50-13,ASB50-2,ASB 50-12,ASB 50-5 and ASB 50-10 were new compounds,and ASE-10,ASB 50-8a,ASB 50-8b and ASB 50-15 were reported to isolate from A.sylvester for the first time.From the changing of ¹H NMR spectra,it was found that ASB 50-8（8a and 8b）,ASB 50-9（9a and 9b）,ASB 50-11（11a and 11b）are isomers,which brings difficulty to separation and structure identification.Meanwhile,as the configurations of the double bonds in ASB 50-2,ASB 50-12,ASB 50-5 and ASB 50-10 would change under the sunlight,the absolute configurations of the new compounds are not confirmed yet.The antioxidant activity of different fractions from the ethanol extract of A.sylvester was evaluated by 1,1-diphenyl-2-picrylhydrazyl（DPPH）method.The ethyl acetate extract（ASE）and n-Butyl alcohol extract（ASB）exhibited good antioxidant potential,while the petroleum ether extract（ASP）exhibited scarcely any antioxidant potential.Thus confirming that the bioactive components of A.sylvester are present in ASE and ASB.Six compounds were selected to further study their antioxidant activity,including1,3,6-tri-O-（E）-caffeoyl-β-D-glucopyranoside,3,4-di-O-（E）-caffeoyl-α/β-glucopyranoside,1,3,4-tri-O-（E）-caffeoyl-β-D-glucopyranoside,1,4-di-O-（E）-caffeoyl-β-D-glucopyranoside,3,6-di-O-（E）-caffeoyl-α/β-glucopyranosideand1-O-（E）-caffeoyl-β-D-glucopyranoside.Resultsshowedthat1,3,6-tri-O-（E）-caffeoyl-β-D-glucopyranosideand1,3,4-tri-O-（E）-caffeoyl-β-D-glucopyranoside exhibited strong antioxidant activity with IC₅₀values of 135.59μM and 111.41μM,respectively.Theα-glucosidase inhibitory activity of different fractions from the ethanol extract of A.sylvester was evaluated by 4-nitrophenyl-α-glucopyranoside（PNPG）method.The ethyl acetate extract（ASE）and n-Butyl alcohol extract（ASB）exhibitedα-glucosidase inhibitory activity with the IC₅₀values of 3.2μg/m L and 28.0μg/m L,respectively.It was further confirmed that the bioactive components of A.sylvester are present in ASE and ASB.Six compounds which have been tested antioxidant activity were applied toα-glucosidase inhibitory assay.Results suggested that1,3,6-tri-O-（E）-caffeoyl-β-D-glucopyranosideand1,3,4-tri-O-（E）-caffeoyl-β-D-glucopyranoside had potentα-glucosidase inhibitory activity with IC₅₀values of 1.16μM and 0.71μM,respectively.This work studied the chemical constituents and bioactivities of A.sylvester systematically,which provides scientific evidence for the medicinal application of A.sylvester,as well as for its development as natural antioxidants and its development and utilization in the treatment of type 2 diabetes.