The Isolation And Identification Of Iridal-type Triterpenoid From Iris Tectorum Maxim

ObjectiveThe rhizome of Iris tectorum Maxim.belongs to iridacea,which is recorded in the Pharmacopecia of People’s Republic of China(ed.2005).It is widely distributed in Guangdong,Guangxi,Sichuan province.It has been used as a folk medicine for the treatment of sore throat,cough and asthma instead of belamcanda chinensis(L.)Redoute.In recent years,a series of the novel iridal-type triterpenoids have been discovered from the rhizome of Iris tectorum Maxim.Iridal-type triterpenoids are a kind of special compounds being different from the ordinary triterpenoids,which are unique metabolites of the Iridaceae,and have a variety of biological activities.This project focuses on the isolation and identification of the Iridal-type triterpenoids from the rhizome of Iris tectorum.The research is to find more novel and active iridal-type triterpenoids,which lays the foundation for further pharmacodynamic studies and research on the mechanism of iridal-type triterpenoids.MethodsUsing a variety of positive and negative reversed phase column chromatography(such as the D101 macroporous resin,silica gel column,MCI column,gel column,ODS column)as well as HPLC,were to isolated iridal-type triterpenoids from the 70%ethanol extract of the rhizome of Iris tectorum Maxim.The structure of the compound was determined based on the data such as mass spectrometry,nuclear magnetic,infrared,ultraviolet,and optical rotation,Mosher’s methods,Snatzke’s methods.Results31 compounds were isolated from the rhizome of Iris tectorum Maxim.Their structures were elucidated as spiroiridal A(IT-1)、spiroiridal B(IT-2)、iritectol H(IT-3)、iritectol I(IT-4)、iritectol J(IT-5)、spirioiridotectal G(IT-6)、spirioiridotectal H(IT-7)、iritectol G(IT-8)、iristectorene I(IT-9)、iristectorene H(IT-10)、isoiridogermanal(IT-11)、iridobelamal A(IT-12)、iridal(IT-13)、iridal 26(IT-14)、iritectol F(IT-15)、22-epiiritectol F(IT-16)、iridojaponal C(IT-17)、iristectorenes B(IT-18)、Iristectorenes D(IT-19)、spirioiridotectal B(IT-20)、Spirioiridotectal A(IT-21)、polycycloiridal D(IT-22)、belamcanolide A(IT-23)、5,7-dihydroxy-8-(1-(4-hydroxy-3-methoxyphenyl)ethyl)3-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one(IT-24)、5,7-dihydroxy-8-(1(4-hydroxy-3-methoxyphenyl)allyl)-3-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one(IT-25)、Irilin D(IT-26)、tectorigenin(IT-27)、6-hydroxybiochanin A(IT-28)、genistein(IT-29)、dihydrokaempferol(IT-30)、(2R,3R)-(+)-4’-O-methyldihydroquercetin(IT-31).ConclusionA total of 31 compounds were isolated from the rhizome of Iris tectorum Maxim,including 23 iridal-type triterpenoids and 8 flavonoids.There are 9 new iridal-type triterpenoids in the triterpenoids,where IT-1 and IT-2 are two novel triterpenoids.And two new flavonoids were also isolated.