Analysis of volatile constituents of Ginkgo leaf

Abstract

Ginkgo biloba L. (Ginkgoaceae) is one of the oldest trees on earth. The medicinal use of its seeds and leaves has been a tradition for thousands of years. The standardized extract (known as EGb 761) contains several biologically active components, among them are terpenes and flavonoid glycosides that are responsible for the pharmacological activities of Ginkgonis folium. According to European Union herbal monographs (EUHM), the leaves of Ginkgo are recommended for the treatment of dementia, cerebral vascular insufficiency, and disorders of the peripheral circulation. The aim of our work was to analyze volatile constituents of Ginkgo leaf. Leaves of 3 Ginkgo trees were analyzed; 2 of which grow in the Medicinal Plants Garden (young trees A and B) and 1 at the Botanical Garden (old tree C) in Bratislava. The leaves were collected in 2014. The essential oil was isolated and quantified using hydrodistillation according to European Pharmacopoeia (Ph. Eur.) The volatile constituents of Ginkgonis folium were evaluated qualitatively and quantitatively using gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). We identified 16 constituents of the leaves of tree A, 18 in tree B, and 14 in tree C. The volatiles of the 3 trees differ in the respective amounts of monoterpenoids, hydrocarbons, fatty acids, and their methyl esters. The following constituents were identified in all of the 3 trees in largest percentage: hexahydrofarnesyl acetone (23.6%, 16.0%, and 27.7%), α-linolenic acid methyl ester (14.8%, 20.7%, and 15.1%), and pentacosane (22.2%, 22.4%, and 21.9%). Other identified compounds include the monoterpenes (E)-α-ionone and (E)-β-ionone.