Simultaneous isolation and preparation of four iridoid glycosides from Lamiophlomis rotata by preparative RP-HPLC

Objective To establish a gradient preparative chromatography,RP-HPLC,and mass spectrometry(MS) method for the preparation and identification of four iridoid glycosides from Tibetan medicinal herb Lamiophlomis rotata.Methods After the plant was extracted with water,the crude extract was purified by polyamide column and macroporous adsorptive resins column.Then preparative liquid chromatography was used to isolate shanzhiside methylester,phloyoside II,loganin,and 8-O-acetyl-shanzhiside methylester.The samples were identified by HPLC and MS.Results MS determination indicated that the four monomers were identical to be shanzhiside methylester,phloyoside II,loganin,and 8-O-acetyl-shanzhiside methylester.The results showed that purities of the products were 95.7%(shanzhiside methylester),94.8%(phloyoside II),96.3%(loganin),and 98.2%(8-O-acetyl-shanzhiside methylester),respectively.Conclusion The method has good separative effect.It is suitable to be used for the prepared separation of four iridoid glycosides from L.rotata.