title: Assessing the quality of Smilacis Glabrae Rhizoma (Tufuling) by colormetrics and UPLC-Q-TOF-MS.
abstract: BACKGROUND
  The quality of the materials used in Chinese medicine (CM) is generally assessed based on an analysis of their chemical components (e.g., chromatographic fingerprint analysis). However, there is a growing interest in the use of color metrics as an indicator of quality in CM. The aim of this study was to investigate the accuracy and feasibility of using color metrics and chemical fingerprint analysis to determine the quality of Smilacis Glabrae Rhizoma (Tufuling) (SGR). The SGR samples were divided into two categories based on their cross-sectional coloration, including red SGR (R-SGR) and white SGR (W-SGR).
  
  
  METHODS
  Forty-three samples of SGR were collected and their colors were quantized based on an RGB color model using the Photoshop software. An ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOF MS) system was used for chromatographic fingerprint analysis to evaluate the quality of the different SGR samples. Hierarchical cluster analysis and dimensional reduction were used to evaluate the data generated from the different samples. Pearson correlation coefficient was used to evaluate the relationship between the color metrics and the chemical compositions of R-SGR and W-SGR.
  
  
  RESULTS
  The SGR samples were divided into two different groups based on their cross-sectional color, including color A (CLA) and B (CLB), as well as being into two separate classes based on their chemical composition, including chemical A (CHA) and B (CHB). Standard fingerprint chromatograms were for CHA and CHB. Statistical analysis revealed a significant correlation (Pearson's r = -0.769, P < 0.001) between the color metrics and the results of the chemical fingerprint analysis.
  
  
  CONCLUSIONS
  The SGR samples were divided into two major clusters, and the variations in the colors of these samples reflected differences in the quality of the SGR material. Furthermore, we observed a statistically significant correlation between the color metrics and the quality of the SGR material.
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.|School of Pharmacy, Gui Yang Collage of Traditional Chinese Medicine, Guiyang, 550002 China.
authors.forename: Xicheng
authors.initials: X
authors.lastname: He
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yi
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.
authors.forename: Yina
authors.initials: Y
authors.lastname: Tang
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.
authors.forename: Jianye
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.
authors.forename: Yazhou
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Gui Yang Collage of Traditional Chinese Medicine, Guiyang, 550002 China.
authors.forename: Lisha
authors.initials: L
authors.lastname: Dong
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist Univesity, Hong Kong, China.
authors.forename: Hubiao
authors.initials: H
authors.lastname: Chen
keywords: Colormetrics; Fingerprint analysis; Smilacis Glabrae Rhizoma