title: Discrimination between genetically identical peony roots from different regions of origin based on 1H-nuclear magnetic resonance spectroscopy-based metabolomics: determination of the geographical origins and estimation of the mixing proportions of blended samples.
abstract: Sixty peony root training samples of the same age were collected from various regions in Korea and China, and their genetic diversity was investigated for 23 chloroplast intergenic space regions. All samples were genetically indistinguishable, indicating that the DNA-based techniques employed were not appropriate for determining the samples' regions of origin. In contrast, (1)H-nuclear magnetic resonance ((1)H-NMR) spectroscopy-based metabolomics coupled with multivariate statistical analysis revealed a clear difference between the metabolic profiles of the Korean and Chinese samples. Orthogonal projections on the latent structure-discrimination analysis allowed the identification of potential metabolite markers, including γ-aminobutyric acid, arginine, alanine, paeoniflorin, and albiflorin, that could be useful for classifying the samples' regions of origin. The validity of the discrimination model was tested using the response permutation test and blind prediction test for internal and external validations, respectively. Metabolomic data of 21 blended samples consisting of Korean and Chinese samples mixed at various proportions were also acquired by (1)H-NMR analysis. After data preprocessing which was designed to eliminate uncontrolled deviations in the spectral data between the testing and training sets, a new statistical procedure for estimating the mixing proportions of blended samples was established using the constrained least squares method for the first time. The predictive procedure exhibited relatively good predictability (adjusted R (2) = 0.7669), and thus has the potential to be used in the quality control of peony root by providing correct indications for a sample's geographical origins.
authors.affiliation: College of Pharmacy, Seoul National University, Seoul, 151-742, South Korea.
authors.forename: Jung A
authors.initials: JA
authors.lastname: Um
authors.forename: Young-Geun
authors.initials: YG
authors.lastname: Choi
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Lee
authors.forename: Yun Sun
authors.initials: YS
authors.lastname: Lee
authors.forename: Chang Ju
authors.initials: CJ
authors.lastname: Lim
authors.forename: Young A
authors.initials: YA
authors.lastname: Youn
authors.forename: Hwa Dong
authors.initials: HD
authors.lastname: Lee
authors.forename: Hi Jae
authors.initials: HJ
authors.lastname: Cho
authors.forename: Jeong Hill
authors.initials: JH
authors.lastname: Park
authors.forename: Young Bae
authors.initials: YB
authors.lastname: Seo
authors.forename: Hsun-chih
authors.initials: HC
authors.lastname: Kuo
authors.forename: Johan
authors.initials: J
authors.lastname: Lim
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Yang
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Kwon
authors.forename: Jeongmi
authors.initials: J
authors.lastname: Lee
mesh_terms: D000409:Alanine / Q000032:analysis / Q000378:metabolism; D001120:Arginine / Q000032:analysis / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001952:Bridged-Ring Compounds / Q000032:analysis / Q000378:metabolism; D002681:China; D002736:Chloroplasts / Q000737:chemistry* / Q000378:metabolism; D021901:DNA, Intergenic / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D005960:Glucosides / Q000032:analysis / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D055432:Metabolomics / Q000706:statistics & numerical data*; D039821:Monoterpenes / Q000032:analysis / Q000378:metabolism; D015999:Multivariate Analysis; D029596:Paeonia / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D058974:Phylogeography; D018517:Plant Roots / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011786:Quality Control; D056910:Republic of Korea; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000378:metabolism; D006027:Glycosides
chemical_list: D000409:Alanine; D001120:Arginine; D015415:Biomarkers; D001952:Bridged-Ring Compounds; D021901:DNA, Intergenic; D018744:DNA, Plant; D005960:Glucosides; D039821:Monoterpenes; D005680:gamma-Aminobutyric Acid; C015423:peoniflorin; D006027:Glycosides; C014959:albiflorin