Quantitative Analysis of Bilobalide and Ginkgolides from Ginkgo biloba Leaves and Ginkgo Products Using 1H-NMR

Young Hae Choi; Hyung-Kyoon Choi; Arno Hazekamp; Paloma Bermejo; Yvonne Schilder; Cornelis Erkelens; Robert Verpoorte

doi:10.1248/cpb.51.158

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Quantitative Analysis of Bilobalide and Ginkgolides from Ginkgo biloba Leaves and Ginkgo Products Using ¹H-NMR

Young Hae Choi, Hyung-Kyoon Choi, Arno Hazekamp, Paloma Bermejo, Yvonne Schilder, Cornelis Erkelens, Robert Verpoorte

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Keywords: bilobalide, ginkgolide, ¹H-NMR spectrometry, quantitative analysis, Ginkgo biloba leaves, Ginkgo products

JOURNAL FREE ACCESS

2003 Volume 51 Issue 2 Pages 158-161

DOI https://doi.org/10.1248/cpb.51.158

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Abstract

¹H-NMR spectrometry was applied to the quantitative analysis of the bilobalide, ginkgolides A, B, and C in Ginkgo biloba leaves and six kinds of commercial Ginkgo products without any chromatographic purification. The experiment was performed by the analysis of each singlet H-12, which were well separated in the range of δ 6.0—7.0 in the ¹H-NMR spectrum. However, the H-12 protons of bilobalide and ginkgolides may have overlapped with H-6 or H-8 protons of the Ginkgo flavonoids. Therefore, the optimum ¹H-NMR solvent for the analysis of the compound was selected through the evaluation of solvent effects on the resolution of these signals from the compounds. Acetone-d₆–benzene-d₆ (50 : 50) was found to be the best one among the solvents evaluated. The quantity of the compounds was calculated by the relative ratio of the intensity of each compound to the known amount of internal standard (25 μg/ml), phloroglucinol. This method allows rapid and simple quantitation of underivatized bilobalide and ginkgolides in 5 min without any pre-purification steps.

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