Triterpenoids From Phellinus Igniarius And Galla Chinensis

Natural products are an important source for new drug discovery.Sanghuang is the fruiting body of Phellinus sp..Galla chinensis is a gall mainly caused by the Chinese aphid that parasite on the leaves of Rhus sp..Both of them are recorded as important medicinal resources in the "Compendium of Materia Medicas" and other ancient medical books.This paper mainly discussed triterpenoids from Phellinus igniarius and Galla chinensis.The methanol extract of the Phellinus igniarius was subjected to column chromatography over silica gel,ODS,Toyopearl HW 40F,MCI CHP20P,Sephadex LH-20,and semi-preparative high performe liquid chromatography.Totally 27 compounds were obtained,including 7 triterpenoids,1 sesquiterpene,4 phenylpropanoids,7 sterols and 8 pyranones.The structures of compounds were identified by extensive data analyses including 1H NMR,13C NMR,high resolution mass spectrometry,chemical correlation and X-ray single crystal diffraction.Compounds 1-27 were identified to be 3β-hydroxy-22R,25-epoxylanosta-7,9-dien-15one（1）,22R,25-epoxylanosta-8-en-2β,3β,15α-triol（2）,22R,25-epoxylanosta-7,9-dien-2β,3β,15a-triol（3）,2β,3β,11α,15α,22R,26-hexahydroxylanosta-8,24-dien-7-one（4）,2,15α,22R,26-tetrahydroxylanosta-1,7,9,24-tetraen-2-one（5）,2β,3β,22R,26-tetrahydroxylanosta-7,9,24-trien-1 5-one（6）,3-O-β-D-glucopyranosyl-3,22R,24-trihydroxy-25,26,27-trinorlanosta-7,9（14）-dien-15-one（7）,（2R）-1-（3’,5’-dichloro-4’-methoxyphenyl）-2,3-propanediol（8）,epoxyconiferyl alcohol（9）,osmundacetone（10）,scopoletin（11）,3β-hydroxycinnamolide（12）,phellinignincisterol C（13）,stellasterol（14）,ergosterol（15）,ergost-7,9（11）,22-trien-3β,5α,6α-triol（16）,cerevisterol（17）,（3β,5α,6β,22E）-6-methoxyergosta-7,22-diene-3,5-diol（18）,ergosterol peroxide（19）,baumin（20）,phelligridin E（21）,inonotusin B（22）,inoscavin A（23）,phellibaumins A（24）,phellifuropyranone A（25）,phelligridimer A（26）,davallialactone（27）.Among them,5 new compounds（1-3,6,8）was found and compound 9 was isolated from Phellinus fungis for the first time.In addition,the absolute configuration of compound 7 was attempted to validate through synthesis of 22S and 22R analogues with the same side chains as compound 7.The activity evaluation showed that compounds 20,26,27 had neuroprotective activity at a concentration of 20 μM.Chemical investigation on the ethyl acetate extract of Galla chinensis led to isolations of six tirucallane triterpenoids and their structures were identified as（24Z）-11-hydroxytirucall-7,24-dien-3-oxo-26-oic acid（28）,densiflorinic acid A（29）,masticadienonic acid（30）,isomasticadienonic acid（31）,masticadienolic acid（32）,isomasticadienolic acid（33）,respectively.Among them,compound 28 was isolated for the first time and compounds 29-33 were isolated from Galla Chinensis for the first time.Compounds 30-32 showed neuroprotective activity at a concentration of 1.6μM.To sum up,a total of 33 compounds（1-33）were isolated and identified from Phellinus igniarius and Galla chinensis,including 6 new compounds（1-3,6,8 and 28）.Compound 9 was isolated from Phellinus fungis for the first time and triterpenes（28-33）were isolated from Galla chinensis for the first time.Six compounds（20,26,27,30-32）were found to have neuroprotective activity in vitro.The above studies not only enriched the chemical composition of Phellinus igniarius and Galla chinensis,but also found compounds with neuroprotective activity.