Planta Medica International Open 2017; 4(S 01): S1-S202
DOI: 10.1055/s-0037-1608584
Lecture Session – Quality Control
Georg Thieme Verlag KG Stuttgart · New York

Quality assessment of Ginkgo biloba supplements based on a single HPLTC Method

D Frommenwiler
1   CAMAG, Muttenz, Switzerland
2   Department of Pharmacology and Pharmacognosy, University of Barcelona, Barcelona, Switzerland
,
A Booker
3   UCL School of Pharmacy, University of London, London, United Kingdom
4   Division of Herbal and East Asian Medicine, Department of Life Sciences, University of Westminster, London, United Kingdom
,
M Heinrich
3   UCL School of Pharmacy, University of London, London, United Kingdom
,
E Reich
1   CAMAG, Muttenz, Switzerland
,
S Cañigueral
2   Department of Pharmacology and Pharmacognosy, University of Barcelona, Barcelona, Switzerland
› Author Affiliations
Further Information

Publication History

Publication Date:
24 October 2017 (online)

 
 

    Ginkgo biloba L. (GB) is one of the top-selling herbal products in the world. The extract of GB used in commercial preparation is often standardized to 24% of flavonol glycosides and 6% terpene lactones. Being a high-value herbal (medicinal) product, GB extracts may be a subject for economically driven adulteration.

    In [1] we reported that of 35 GB products (containing extracts and plant material) from the UK market only two show the HPTLC fingerprint that described in the Ph. Eur. and USP monographs for Ginkgo extract. All others contain high levels of quercetin, rutin, or additional zones not characteristic of GB.

    Aiming at a better characterization of the adulterants, additional detection modes were evaluated and another derivatization step was added to the original HPTLC method for identification. Beside added rutin and/or quercetin, the modified method detects added Buckwheat and Styphnolobium japonicum (L.) Schott (SJ – syn.: Sophora japonica L.) fruit prior to derivatization as well as SJ flower after derivatization. Additional HPTLC methods were established to verify the levels of quercetin (NMT 0.5%) and the presence of genistein as marker for SJ fruit.

    Samples were also assayed for total flavonoid glycosides by HPLC according to the USP and Ph. Eur monographs on Ginkgo leaves and extract. Twelve samples were in compliance with the total amount of flavonol glycoside specified in the monographs. However, ten of those had elevated levels of quercetin in HPTLC fingerprint. This was confirmed with an additional HPLC limit test for rutin and quercetin described in the ginkgo extract monograph from USP.

    With the proposed modified HPTLC method for identification of GB several types of adulteration can be detected without additional chromatography. That significantly saves cost in a routine setting.

    [1] Booker A, Frommenwiler D, Reich E, Horsfield S, Heinrich M. J Herb Med 2016; 6: 79 – 87


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