title: Rapid structural determination of amides in Piper longum by high-performance liquid chromatography combined with ion trap mass spectrometry.
abstract: A reversed-phase liquid chromatography/tandem multistage mass spectrometry (MS/MS) method was developed for the characterization of amides from the extracts of Piper longum. The characteristic fragmentations of the amides found in P. longum showed diagnostic structural information. Extracted ion chromatography (EIC) and constant neutral losses were used to guide the search for the amides of interest. Amides of known structures that contain four subtypes of amides were rapidly determined, and novel amides were also identified for this plant. Forty-two amides were rapidly identified, of which 22 were found in this plant for the first time and 9 were new compounds. The method is convenient and sensitive, especially for minor components in the unpurified, complex mixture; the structures of unknown constituents could be determined, in the absence of authentic sample, by comparison of the fragmentation patterns with those of homologous compounds.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
authors.forename: Cuirong
authors.initials: C
authors.lastname: Sun
authors.forename: Saifeng
authors.initials: S
authors.lastname: Pei
authors.forename: Yuanjiang
authors.initials: Y
authors.lastname: Pan
authors.forename: Zhiquan
authors.initials: Z
authors.lastname: Shen
mesh_terms: D000577:Amides / Q000737:chemistry* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000378:metabolism; D031701:Piper / Q000737:chemistry* / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000577:Amides; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts