title: High-performance thin-layer chromatographic fingerprints of isoflavonoids for distinguishing between Radix Puerariae Lobate and Radix Puerariae Thomsonii.
abstract: The roots of Pueraria lobata (Wild.) Ohwi and Pueraria thomsonii Benth have been officially recorded in all editions of Chinese Pharmacopoeia under the same monograph 'Gegen' (Radix Puerariae, RP). However, in its 2005 edition, the two species were separated into both individual monographs, namely 'Gegen' (Radix Puerariae Lobatae, RPL) and 'Fenge' (Radix Puerariae Thomsonii, RPT), respectively, due to their obvious content discrepancy of puerarin, the major active constituent. In present paper, the fingerprint of high-performance thin-layer chromatography (HPTLC) combining digital scanning profiling was developed to identify and distinguish the both species in detail. The unique properties of the HPTLC fingerprints were validated by analyzing ten batches of Pueraria lobata and P. thomsonii samples, respectively. The common pattern of the HPTLC images of the roots of Pueraria spp. and the respective different ratios of the chemical distribution can directly discern the two species. The corresponding digital scanning profiles provided an easy way for quantifiable comparison among the samples. Obvious difference in ingredient content and HPTLC patterns of the two species questioned their bio-equivalence and explained that recording both species separately in the current edition of Chinese Pharmacopoeia (2005 edition) is reasonable due to not only the content of major constituent, puerarin, but also the peak-to-peak distribution in the fingerprint and integration value of the total components. Furthermore, the HPTLC fingerprint is also suitable for rapid and simple authentication and comparison of the subtle difference among samples with identical plant resource but different geographic locations.
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
authors.forename: Si-Bao
authors.initials: SB
authors.lastname: Chen
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Liu
authors.forename: Run-Tao
authors.initials: RT
authors.lastname: Tian
authors.forename: Da-Jian
authors.initials: DJ
authors.lastname: Yang
authors.forename: Shi-Lin
authors.initials: SL
authors.lastname: Chen
authors.forename: Hong-Xi
authors.initials: HX
authors.lastname: Xu
authors.forename: Albert S C
authors.initials: AS
authors.lastname: Chan
authors.forename: Pei-Shan
authors.initials: PS
authors.lastname: Xie
mesh_terms: D002855:Chromatography, Thin Layer / Q000379:methods*; D005419:Flavonoids / Q000032:analysis*; D029001:Herbal Medicine; D007202:Indicators and Reagents; D029908:Pueraria / Q000737:chemistry*; D012015:Reference Standards; D013045:Species Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D005419:Flavonoids; D007202:Indicators and Reagents