title: An effective identification and quantification method for Ginkgo biloba flavonol glycosides with targeted evaluation of adulterated products.
abstract: BACKGROUND
  Ginkgo biloba L. (Ginkgoaceae) leaf extract is one of the most popular herbal products on the market, as it contains flavone glycosides (≥ 24%) and terpene lactones (≥ 6%), which are proposed to have significant physiological effects. Unfortunately, the challenging financial climate has resulted in a natural health product market containing adulterated ginkgo products.
  
  
  OBJECTIVE
  42 ginkgo samples were analyzed to establish an HPLC profile for authentic ginkgo and common ginkgo adulterants, and to develop a method capable of easily detecting adulteration in ginkgo commercial products.
  
  
  METHODS
  In this study an efficient and targeted HPLC analysis method was established that is capable of distinguishing flavonol glycosides and aglycones simultaneously for the evaluation of ginkgo powdered extracts (PEs) and finished products in a single, 13 min run. Thirteen ginkgo leaf samples, fifteen standardized powdered extracts, and fourteen commercially available ginkgo products have been analyzed using this new HPLC method. Chromatograms were compared to six standard reference materials: one flavonol glycoside (rutin), three aglycones (quercetin, kaempferol and isorhamnetin), and two isoflavones (genestin and genistein). The quantitative chromatographic data was interpreted by principal component analysis (PCA), which assisted in the detection of unexpected chromatographic features in various adulterated botanical products.
  
  
  RESULTS
  Only three of the commercially available ginkgo finished products tested in this study were determined to be authentic, with flavonol glycoside rutin, and aglycones quercetin, kaempferol, and isorhamnetin found to be common adulterants in the ginkgo powdered extract and finished product samples.
  
  
  CONCLUSIONS
  Despite evidence of adulteration in most of the samples, each of the samples discussed herein met most of the current pharmacopeial standards. It is therefore critical that a preliminary evaluation be utilized to detect adulteration in commercial ginkgo products, prior to the acid hydrolysis procedure utilized in the current testing methods.
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada; Canadian Institute of Medicinal Plants, 12233 Riverside Way, Richmond, BC V6W 1K8, Canada; Hubei University of Chinese Medicine, Wuhan 430000, PR China. Electronic address: ycma@canphyto.com.
authors.forename: Yuan-Chun
authors.initials: YC
authors.lastname: Ma
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada. Electronic address: anahitam@canphyto.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Mani
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada; Canadian Institute of Medicinal Plants, 12233 Riverside Way, Richmond, BC V6W 1K8, Canada.
authors.forename: Yaling
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada.
authors.forename: Jaclyn
authors.initials: J
authors.lastname: Thomson
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada; Canadian Institute of Medicinal Plants, 12233 Riverside Way, Richmond, BC V6W 1K8, Canada.
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada.
authors.forename: Flavie
authors.initials: F
authors.lastname: Peudru
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Chen
authors.affiliation: Canadian Phytopharmaceuticals Corp., 12233 Riverside Way, Richmond, BC V6W 1K8, Canada; Canadian Institute of Medicinal Plants, 12233 Riverside Way, Richmond, BC V6W 1K8, Canada.
authors.forename: Mai
authors.initials: M
authors.lastname: Luo
authors.affiliation: Natural Health Products Program, Aquatic and Crop Resource Development, National Research Council of Canada, Halifax, Nova Scotia B3H 3Z1, Canada.
authors.forename: Junzeng
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Natural Health Products Program, Aquatic and Crop Resource Development, National Research Council of Canada, Halifax, Nova Scotia B3H 3Z1, Canada.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Chapman
authors.affiliation: Hubei Nuokete Pharmaceutical Co., Ltd., Xiaochang, Hubei 432900, PR China.
authors.forename: Zhen-Tuo
authors.initials: ZT
authors.lastname: Shi
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004340:Drug Contamination / Q000517:prevention & control*; D044948:Flavonols / Q000032:analysis*; D019833:Genistein / Q000032:analysis; D020441:Ginkgo biloba / Q000737:chemistry*; D006027:Glycosides / Q000032:analysis*; D044949:Kaempferols / Q000032:analysis; D007783:Lactones / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D011794:Quercetin / Q000031:analogs & derivatives / Q000032:analysis; D012015:Reference Standards; D013729:Terpenes / Q000032:analysis
chemical_list: D044948:Flavonols; D006027:Glycosides; D044949:Kaempferols; D007783:Lactones; D010936:Plant Extracts; D013729:Terpenes; C047368:3-methylquercetin; C006552:kaempferol; D011794:Quercetin; D019833:Genistein
keywords: Adulteration; Ginkgo biloba; Ginkgo supplements; LC-MS; PCA; Pharmacopeia