title: Improved extraction of ginkgotoxin (4'-O-methylpyridoxine) from Ginkgo biloba products.
abstract: A simple extraction procedure was applied to the analysis of canned/packaged white nuts and Ginkgo biloba extracts. Extraction by shaking with water at room temperature was more convenient to use than a previously published Soxhlet procedure for analysis of packaged Ginkgo biloba seeds (white nuts) for ginkgotoxin; recoveries from spiked dried seeds by the simple extraction procedure averaged 76%. Determination was by liquid chromatography with UV or fluorescence detection. Recoveries of ginkgotoxin from a spiked and unspiked natural health product (powder from Ginkgo biloba capsules) were equivalent by both procedures; recovery from spiked powder by the simple extraction procedure was 81%. Application of this extraction procedure in the analysis of 6 samples of white nuts (vacuum packaged and canned products) showed that free ginkgotoxin was present in 5 samples at concentrations up to 25 microg/g dry weight. Total ginkgotoxin was determined after hydrolysis with beta-glucosidase of sample extracts in which a peak corresponding to the 5'-O-glucoside was detected. Ginkgotoxin was determined in 10 Ginkgo biloba natural health products by the same method at levels up to 181 microg/g.
authors.affiliation: Health Canada, Health Products and Food Branch, Food Research Division, Address Locator 2203D, Ottawa, Ontario, K1A 0L2, Canada.
authors.forename: Guillaume A
authors.initials: GA
authors.lastname: Lawrence
authors.forename: Peter M
authors.initials: PM
authors.lastname: Scott
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid; D020441:Ginkgo biloba / Q000378:metabolism*; D006868:Hydrolysis; D010936:Plant Extracts; D010946:Plants, Medicinal; D011736:Pyridoxine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D013696:Temperature; D014466:Ultraviolet Rays; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: C406624:4'-O-methylpyridoxine; D010936:Plant Extracts; D001617:beta-Glucosidase; D011736:Pyridoxine