title: Analysis of iridoid glucosides in Hedyotis diffusa by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.
abstract: An HPLC-DAD-ESI-MS/MS method was developed for analysis of iridoid glucosides (IGs) from Hedyotis diffusa Willd. The optimized separation condition was achieved with the Complex Sample Analysis Software System (CSASS) software, under which the whole analytes were achieved complete resolution especially for some isomeric IGs. Based on the UV and fragmentations, eleven IGs were detected. According to the fragmentation patterns of the three standard IGs, especially those of the isomeric standards, seven IGs including three pairs of isomers were unambiguous/tentatively identified. For the isomeric IGs with methyl ester or carboxyl group at C-4, the extents of the losses of CH3OH and/or H2O from their molecular and/or the aglycone adducts are useful for the differentiation of the stereoisomers in positive ion (PI) mode, which depends on the stereochemistry of the hydroxyl group on the cyclopentanoid unit.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
authors.forename: Cunman
authors.initials: C
authors.lastname: Li
authors.forename: Xingya
authors.initials: X
authors.lastname: Xue
authors.forename: Dayong
authors.initials: D
authors.lastname: Zhou
authors.forename: Feifang
authors.initials: F
authors.lastname: Zhang
authors.forename: Qing
authors.initials: Q
authors.lastname: Xu
authors.forename: Lingling
authors.initials: L
authors.lastname: Ren
authors.forename: Xinmiao
authors.initials: X
authors.lastname: Liang
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D032064:Hedyotis / Q000737:chemistry* / Q000145:classification*; D039823:Iridoids / Q000032:analysis* / Q000737:chemistry; D015394:Molecular Structure; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D011208:Powders; D012015:Reference Standards; D015203:Reproducibility of Results; D012984:Software; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D039823:Iridoids; D010936:Plant Extracts; D011208:Powders