title: Sparse partial-least-squares discriminant analysis for different geographical origins of Salvia miltiorrhiza by (1) H-NMR-based metabolomics.
abstract: BACKGROUND
  (1) H nuclear magnetic resonance (NMR) spectroscopy has clear advantages in respect of detecting various primary and secondary metabolites in plants simultaneously, non-targeted and non-destructively.
  
  
  OBJECTIVE
  To establish a method for detecting both primary and secondary metabolites in Salvia miltiorrhiza and screening potential geographical biomarkers effectively.
  
  
  METHODS
  Primary and secondary metabolites of S. militiorrhiza were detected and identified by (1) H-NMR fingerprint. Sparse partial-least-squares discriminant analysis (sPLS-DA) was undertaken for classification and variable selection in a one-step procedure and the classification error rates were implemented to estimate the cluster validation of sPLS-DA. Potential candidate metabolites by characterised different geographical origins of S. miltiorrhiza were identified according to the sparse loading vectors. The levels of these metabolites were quantified and evaluated by Kruskal-Wallis tests and also showed significant difference.
  
  
  RESULTS
  Twenty-six primary and secondary metabolites were identified in samples from different regions. The results suggest that malonate and succinate can be possibly recognised as the key markers for discriminating the geographical origin of S. miltiorrhiza based on the regulation and influence on the root respiratory rates of plants.
  
  
  CONCLUSIONS
  (1) H-NMR metabolic profiling combination with PLS-DA provided a very efficient and visualised representation of similarities and dissimilarities between S. miltiorrhiza samples.
authors.affiliation: Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, PR China; Key Laboratory of TCM Chemistry and Analysis, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, PR China; Research and Development Center of TCM, Tianjin International Joint Academy of Biotechnology and Medicine, Tianjin, 300457, PR China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Jiang
authors.forename: Chunhua
authors.initials: C
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yifan
authors.initials: Y
authors.lastname: Feng
authors.forename: Yuefei
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D016002:Discriminant Analysis; D016018:Least-Squares Analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D055432:Metabolomics / Q000379:methods*; D027561:Salvia miltiorrhiza / Q000378:metabolism*; D064210:Secondary Metabolism
keywords: Danshen; NMR; geographical origin; metabolomics; sparse PLS-DA; sparse loading vectors