title: Application of NIR and MIR spectroscopy for rapid determination of antioxidant activity of Radix Scutellariae from different geographical regions.
abstract: BACKGROUND
  The beneficial health effects of traditional Chinese medicines are often attributed to their potent antioxidant activities, usually established in vitro. However, these wet chemical methods for determining antioxidant activities are time-consuming, laborious, and expensive.
  
  
  OBJECTIVE
  This study was conducted to establish a rapid determination of antioxidant activity of Radix Scutellariae using near-infrared (NIR) and mid-infrared (MIR) spectroscopy.
  
  
  METHODS
  Antioxidant capabilities were evaluated using 2,2-diphenyl-1-picrylhydrazyl hydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. The total flavonoid contents (TFCs) of Radix Scutellariae were measured by the aluminium chloride colorimetric method. The same sample was then scanned using NIR and MIR spectroscopy. Chemometrics analysis using partial least-squares (PLS) regression was performed to establish the models for predicting the antioxidant activities of Radix Scutellariae.
  
  
  RESULTS
  A better predictive performance was achieved using PLS models based on NIR data. The determination coefficient (R(2)) and the residual predictive deviation (RPD) for the validation set were 0.9298 and 2.84 for DPPH, and 0.9436 and 2.66 for TFCs, respectively. MIR-PLS algorithms gave a slightly lower reliability (R(2) = 0.9090 and 0.9374, RPD = 2.01 and 2.42, for DPPH and TFC, respectively). Very comparable results for ORAC were obtained with the two methods.
  
  
  CONCLUSIONS
  The developed spectroscopic method can be successfully applied in high-throughput screening of the antioxidant capability of Radix Scutellariae samples. It can also be a viable and advantageous alternative to laborious chemical procedures.
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.|State Key Laboratory of Dao-di Herbs, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.|Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
authors.forename: Jingxia
authors.initials: J
authors.lastname: He
authors.affiliation: State Key Laboratory of Dao-di Herbs, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
authors.forename: Fajie
authors.initials: F
authors.lastname: Li
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
authors.forename: Raorao
authors.initials: R
authors.lastname: Li
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.|Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
authors.forename: Jianchun
authors.initials: J
authors.lastname: Su
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
authors.forename: Jidan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.|State Key Laboratory of Dao-di Herbs, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000032:analysis / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis; D057166:High-Throughput Screening Assays; D016018:Least-Squares Analysis; D031364:Scutellaria baicalensis / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D000975:Antioxidants; D004365:Drugs, Chinese Herbal; D005419:Flavonoids
keywords: Radix Scutellariae; antioxidant capacity; chemometrics; mid-infrared; near-infrared