Background:
The official compendium of the quantification of ginkgo flavonoids from
Ginkgo biloba extract has been proposed using HPLC. The drawbacks of this technique appear to be
due to the restricted efficiency in terms of the recovery results and suitability of the system for the
quantification of these compounds. This study investigated the potential advantages and limitations
of the development of efficient extraction methods for the recovery of flavonol glycosides (quercetin,
kaempferol and isorhamnetin) and terpene trilactones (bilobalide, ginkgolide A, ginkgolide B and
ginkgolide C) using extraction, quantification and detection techniques, namely, GC-FID and
UHPLC-DAD, which are alternatives to those techniques available in the literature.
Methods:
Two different extraction methodologies have been developed for the determination of flavonoids
(quercetin, kaempferol and isorhamnetin) and terpene trilactones (bilobalide, ginkgolide A,
ginkgolide B and ginkgolide C) using ultra-high-pressure liquid chromatography coupled to a diode
array detector and gas chromatography coupled to a flame ionization detector.
Results:
In this study, the Ginkgo biloba extract mass, hydrolysis preparation method (with or without
reflux), and volume of the extraction solution seemed to affect the ginkgo flavonoid recovery.
The UHPLC-based method exhibited higher extraction efficiency for ginkgo flavonoid quantification
compared to the pharmacopoeial method. The developed method exhibited higher extraction efficiency
for terpene quantification compared to the previous method that used extractive solution without
pH adjustment, with less time of extraction and less amount of the sample and organic solvent
aliquots.
Conclusion:
The UHPLC and GC analysis methods established in this study are both effective and
efficient. These methods may improve the quality control procedures for ginkgo extract and commercial
products available in today´s natural health product market. The results indicate that redeveloped
extraction methods can be a viable alternative to traditional extraction methods.
Effect of Ginkgo Biloba Extract on N-Methyl-D-Aspartic Acid Receptor Subunit 2B Expression in a Salicylate-Induced Ototoxicity Model
