Analysis of Ginkgo biloba for the Presence of Ginkgotoxin and Ginkgotoxin 5′-Glucoside
| Autor: | Peter M. Scott, David Lewis, Guillaume A. Lawrence, Benjamin P.-Y. Lau |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Pharmacology
Chromatography biology Chemistry Ginkgo biloba Ginkgo Extraction (chemistry) biology.organism_classification Mass spectrometry Analytical Chemistry chemistry.chemical_compound Glucoside Environmental Chemistry Ginkgoales Ginkgotoxin Agronomy and Crop Science Quantitative analysis (chemistry) Food Science |
| Zdroj: | Journal of AOAC INTERNATIONAL. 83:1313-1320 |
| ISSN: | 1944-7922 1060-3271 |
| DOI: | 10.1093/jaoac/83.6.1313 |
| Popis: | Hot water extracts of Ginkgo biloba seeds were analyzed for the presence of ginkgotoxin (4′-O-methylpyridoxine) by reversed-phase liquid chromatography (LC) using methanol–0.05M KH2PO4 (1 + 9, v/v) adjusted to pH 3 as mobile phase. Detection was by fluorescence (excitation 280 nm, emission 370 nm). A straight line calibration curve was obtained for the 10–100 ng injected. After addition of β-glucosidase (37°C/h), an earlier eluting peak disappeared and the ginkgotoxin peak increased. The identity of the ginkgotoxin was confirmed by LC/MS and LC/MS/MS. LC/MS/MS also confirmed the 5′-glucoside by comparison with the 3-glucoside. This is the first identification of a glucoside of ginkgotoxin in Ginkgo biloba. An unknown compound of MW 267 also observed in the Ginkgo biloba seed extract was shown not to be 3,5′-diacetylginkgotoxin by its different LC retention time. Extraction of ground Ginkgo biloba seeds with boiling water in a Soxhlet for 2 × 2 h yielded a total of 179 μg/g of free ginkgotoxin. The concentration in powder from Ginkgo biloba capsules was several times lower than this (17–64 μg/g) in 3 samples but higher in another (457 μg/g). Canned ginkgo seeds (white nuts) contained no detectable free ginkgotoxin but the glucoside was present. Different extraction times were studied: 0.5 h gave only 52 μg/g free ginkgotoxin in the ginkgo seeds. However, boiling an extract for 4 h showed about 15% loss of ginkgotoxin and its glucoside. |
| Databáze: | OpenAIRE |
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