Gas chromatographic-mass spectrometric examination of chemical composition of two Eurasian birch (Betula L.) bud exudates and its taxonomical implication

• The chemical composition of buds of two white birches was investigated by GC–MS.
• More than 350 compounds of different classes were identified.
• The compositions varied qualitatively and quantitatively between the species.
• A rapid approach to determination of the taxonomical implications of birch species is proposed.

GC–MS was used to investigate the chemical diversity of bud exudates obtained from two species of white birch in Poland, Betula pendula Roth and Betula pubescens Ehrh. The ether extracts of the bud exudates contained more than 210 organic compounds including: terpenoids, phenylpropenoids of sesquiterpene alcohols and flavonoids. Headspace solid-phase microextraction (HS-SPME) made it possible to detect as many as 140 volatile organic compounds (VOCs), mainly sesquiterpene hydrocarbons and their oxygen derivatives. The chemical compositions of both the ether extracts and the VOCs varied qualitatively and quantitatively between the species. The extracts from B. pendula buds contained predominantly triterpenoids. However, B. pubescens exhibited high amounts of sesquiterpenoids, flavonoid aglycones and phenylpropenoids of caryophyllane series sesquiterpenols. The differences in the composition of compounds in the bud exudates enabled the two species of birch to be differentiated.

While the triterpenoids are specific for Betula pendula, Betula pubescens buds are characterized by the presence of the sesquiterpene phenylpropenoids.Figure optionsDownload as PowerPoint slide