title: Rapid differentiation ofXihuangcaofrom the threeIsodonspecies by UPLC-ESI-QTOF-MS/MS and chemometrics analysis.
abstract: BACKGROUND
  Isodon lophanthoides,I. lophanthoidesvar.graciliflorusandI. serraare the three botanical sources ofXihuangcao, which are often used indiscriminately in herbal products. The aim of this study was to develop a rapid and accurate analytical method to identify the three different botanical sources ofXihuangcaoby combining UPLC-ESI-QTOF-MS with chemometrics analysis.
  
  
  METHODS
  Fifteen batches of plants were collected as reference materials and their chemical profiles were analyzed by UPLC-ESI-QTOF-MS. These data were subsequently processed by statistical methods, including principal component analysis (PCA), hierarchical cluster analysis (HCA) and orthogonal partial least squared discriminant analysis (OPLS-DA). An automated sample class prediction model was also built using Naive Bayes as a class prediction algorithm to rapidly determine the source species of twenty-seven batches of commercialXihuangcaosamples.
  
  
  RESULTS
  The base peak chromatograms of the three authenticated species showed different patterns and twenty-seven peaks were chosen, including six diterpenoids, one phenolic acid and two glycosides to distinguish among these three species. The results showed good differentiation among the three species by PCA, HCA and OPLS-DA.Isodon lophanthoidesvar.gracilifloruswas found to be the major botanical source of the commercial samples.
  
  
  CONCLUSIONS
  UPLC-ESI-QTOF-MS and subsequent chemometrics analysis were demonstrated effective to differentiate among the three different species of plants used asXihuangcao.
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong Special Administrative Region People's Republic of China.
authors.forename: Lai Lai
authors.initials: LL
authors.lastname: Wong
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong Special Administrative Region People's Republic of China ; Research Center for Pharmacognosy, Institute of Chinese Materia Medica, Academy of Chinese Medical Sciences, Beijing, People's Republic of China.
authors.forename: Zhitao
authors.initials: Z
authors.lastname: Liang
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong Special Administrative Region People's Republic of China ; Research Center for Pharmacognosy, Institute of Chinese Materia Medica, Academy of Chinese Medical Sciences, Beijing, People's Republic of China.
authors.forename: Hubiao
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong Special Administrative Region People's Republic of China ; Research Center for Pharmacognosy, Institute of Chinese Materia Medica, Academy of Chinese Medical Sciences, Beijing, People's Republic of China.
authors.forename: Zhongzhen
authors.initials: Z
authors.lastname: Zhao