title: Characterisation of the degradation of salvianolic acid B using an on-line spectroscopic analysis system and multivariate curve resolution.
abstract: BACKGROUND
  Chinese herbal medicines contain complex ingredients that are unstable during the manufacturing process. Current off-line methods are usually time-consuming and inaccurate.
  
  
  OBJECTIVE
  The aim of this study was to develop a continuous-flow-based on-line spectroscopic system for monitoring the degradation of unstable compounds in Chinese herbal medicines.
  
  
  METHODS
  An on-line spectroscopic analysis system in the evaluation of the degradation of unstable compounds was implemented, using salvianolic acid B from Danshen (Radix Salviae Miltiorrhizae) as a model compound. Resolution of the mixture spectra obtained during the reaction was performed with multivariate curve resolution (MCR), and the pure spectra and kinetic profiles of reactant species were reconstructed.
  
  
  RESULTS
  The degradation process of salvianolic acid B is probably a consecutive two-step reaction of the form A → B → C, where A is salvianolic acid B, and B and C are the intermediate and final products, respectively. The intermediate and final products were suggested to be a mixture of lithospermic acid and danshensu [3-(3, 4-dihydroxyphenyl) lactic acid], and a mixture of danshensu and salvianolic acid A, respectively.
  
  
  CONCLUSIONS
  The findings suggested that the combined use of on-line spectroscopic analysis and MCR might be a cheap, readily available, sensitive tool to monitor the transformation of unstable components of Chinese herbal medicines.
authors.affiliation: Pharmaceutical Informatics Institute, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xintian
authors.forename: Qu
authors.initials: Q
authors.lastname: Haibin
mesh_terms: D000465:Algorithms; D001572:Benzofurans / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D013058:Mass Spectrometry; D008956:Models, Chemical; D015394:Molecular Structure; D015999:Multivariate Analysis; D009862:Online Systems; D018517:Plant Roots / Q000737:chemistry; D027561:Salvia miltiorrhiza / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D053630:Depsides
chemical_list: D001572:Benzofurans; D004365:Drugs, Chinese Herbal; C076944:salvianolic acid B; D053630:Depsides