Comprehensive Analysis of Flavonols inGinkgo bilobaProducts by Ultra-High-Performance Liquid Chromatography Coupled with Ultra-Violet Detection and Time-of-Flight Mass Spectrometry

Abstract

The aim of this study was to survey the flavonol compositions of Ginkgo biloba products, especially those on the Japanese market. Sixteen food products, six medicinal products, and raw Ginkgo biloba leaves were examined by ultra-high-performance liquid chromatography coupled with ultra-violet detection and time-offlight mass spectrometry. Eleven flavonol glycosides, three biflavones, and a flavonol aglycone were qualified by analysis of accurate mass spectra. The quantitative data obtained were then applied to multivariate data analysis, and the flavonol compositions of the food and medicinal products were classified into four groups. Most of the food products were classified into the same group as the medicinal products, which contained high percentages of flavonol glycosides. On the other hand, some food products contained high percentages of biflavones or an aglycone.Key words: Ginkgo biloba; flavonols; comprehensive analysis; principal component analysis Ginkgo biloba is a plant of Chinese origin, called ''icho'' in Japanese and ''yin-kuo'' in Chinese. Ginkgo biloba leaves have been used as an herbal medicine in China for 5,000 years. In 1966, the pharmacological effect of an extract of Ginkgo biloba leaves on blood circulation was first reported in the West. 1) In recent years, the extracts have been used globally as herbal medicines to cure dementia and other diseases, 2,3) and also as foods. Annual sales of Ginkgo biloba products were reported to amount to 420 million euros in Germany, 107 million dollars in the United States, and 4.3 billion yen in Japan. 4)Terpene lactones and flavonol glycosides are the main biologically active components in Ginkgo biloba extracts. Terpene lactones have anti-platelet activity and inhibit beta amyloid peptide aggregation.2) Flavonol glycosides are known to act as antioxidants in the human body. The synergistic effects of these components are considered to be effective against Alzheimer's, cardiovascular, and other diseases. 3)In Japan, Ginkgo biloba products are categorized as foods, the origin and content of which are not as strictly regulated as those of medicines. In this circumstance, there is a possibility of inferior quality in some food products, 5) and thus it is necessary to survey the biologically active components of Ginkgo biloba products on the Japanese market.We have reported surveillance of the composition of terpene lactones and flavonols in Ginkgo biloba products.6,7) However, in our previous study, 7) we could not determine the details of the compositions of the flavonols, since many species of flavonol glycosides are degraded into a few flavonol aglycones and sugar units during the hydrolytic process. 8) In determining the details of flavonol composition, the lack of commercial analytical standards appears to be a problem. 5) In previous reports, 9-11) LC-UV methods were reported to determine flavonol glycosides, but peak identification was not sufficient. Although NMR analysis identified peaks in LC-UV and LC-ECD chromatograms, 12,13) it was a very t...

Ginkgo biloba leaf extract EGb 761® as a paragon of the product by process concept

“…A Dutch study showed similarly strong differences in quality among 29 ginkgo products ( Fransen et al, 2010 ). Significant differences in quality between various G. biloba preparations were also found in a Japanese study ( Kakigi et al, 2012 ). Among the preparations analyzed in a Polish study, products were found containing relatively small amounts of flavone glycosides or terpene lactones, but with ginkgolic acid concentrations of up to 392 ppm ( Gawron-Gzella et al, 2010 ).…”

Mass spectrometry‐based approaches to assess the botanical authenticity of dietary supplements

“…Furthermore, eight PFS showed amounts of quercetin, kaempferol, and isorhamnetin that suggested adulteration with synthetic aglycones (Avula, Sagi, Gafner, et al, 2015). Kakigi et al (2012) used a similar targeted analysis based on profiling 15 compounds (11 flavonol glycosides, three biflavones, and quercetin) by UHPLC-UV-TOF-MS. However, the approach was slightly different since it did not comprise full quantification of the compounds.…”

Regulatory science of natural products

“…During the course of our research on the origins of natural products using morphological, genomic, and chemical analyses, we found that the ingredients of some of the following health food products did not originate from the material listed on the label: chondroitin sulfate [ 51 ], white kwao keur ( Pueraria candollei var. mirifica ) [ 52 ], black cohosh [ 53 , 54 ], haru-ukon ( Curcuma aromatica ) [ 55 ], bilberry [ 56 ], ginkgo leaf [ 57 ], chaste berry [ 58 ], and herbal materials for foodstuffs, such as Isodonis Herba and Isodonis extracts [ 59 ] and Sida products [ 60 ]. The average ratio of wrongly labeled products, including those with constituents from the stated origin but containing adulterants, to correctly labeled products was approximately one-third [ 61 ].…”

“…The results tested by the National Consumer Affairs Center of Japan for health food products of chondroitin sulfate and α-lipoic acid also showed a similar ratio in 2008. Furthermore, chromatographic analyses revealed that the content range of active ingredients in health foods, such as bilberry [ 56 , 62 ], vine leaf [ 63 ], ginkgo leaf [ 57 ], and chaste berry [ 58 ], is wider than that of pharmaceutical products.…”