Quantitation of bilobalide and ginkgolides A, B, C and J by means of nuclear magnetic resonance spectroscopy

Abstract

A quantitative 'H NMR procedure for the determination of bilobalide and ginkgolides A, B, C and J in Ginkgo bilobu leaves and in phytopharmaceuticals without prior chromatographic separation of the mixture has been developed. The method is based on the comparison of the integral of each H-12 proton of the five ginkgo terpene trilactones with that of the olefinic protons of the internal standard (maleic acid). These protons are all well separated at 200 MHz and occur in a less crowded region of the NMR spectrum (6.15-6.50 ppm). The selectivity, reproducibility and sensitivity are comparable with high pressure liquid chromatography (HPLC) with refractive index (RI) detection. The minimum amount that can be quantified within 30min at 200MHz is approximately 0.1 mg for all four ginkgolides and bilobalide. Advantages, in comparison with HPLC-RI, are that no reference substances are needed and that for the occasional analysis of a limited number of samples a very significant time-gain can be achieved.

1H NMR-based metabolomics combined with HPLC-PDA-MS-SPE-NMR for investigation of standardized Ginkgo biloba preparations

“…Based on earlier 1 H NMR investigations of Ginkgo biloba extracts (van Beek et al 1993; Choi et al 2003; Li et al 2004), spectra of all samples were acquired in acetone- d 6 with an inter-pulse delay of 2.84 s, which assured full relaxation of magnetization between excitations. The spectra constitute the dataset for the multivariate data analysis, and an overview of the spectra is shown in Fig.…”

Liquid chromatography/electrospray mass spectrometry of bioactive terpenoids inGinkgo biloba L.

“…10 -12 Moreover, totally different approaches, such as biological standardization using the PAF-antagonist properties of ginkgolides 13 and 1 H NMR spectroscopy, 14 have been proposed. Recently, Camponovo et al 15 developed an HPLC method using either thermospray (TSP) MS detection or evaporative light scattering detection (ELSD).…”

Liquid chromatography/electrospray tandem mass spectrometry of terpenoid lactones in Ginkgo biloba

“…To standardize commercial ginkgo products and to carry out quality control studies, assays have been reported based on a wide variety of analytical techniques including HPLC or capillary electrophoresis with UV absorbance detection [20,21], HPLC with refractive index detection [22], HPLC with evaporative light scattering detection (ELSD) [23], gas chromatography (GC) with flame ionization detection [24], GC-mass spectrometry (GC-MS) [25], NMR [26], and liquid chromatography-mass spectrometry (LC-MS) [27][28][29][30]. Although ginkgo extracts usually contain considerable quantities of flavonoids which have strong UV absorption, terpenoid lactones lack UV chromophores so that even trace amounts of co-eluting compounds such as the abundant flavonoids might interfere with their detection.…”