/ Studies on Betula essential oils
Issue in Honor of Prof. Atta-ur-Rahman ARKIVOC 2007 (vii) 335-348 Studies on Betula essential oils K. Hüsnü Can Baser* and Betül Demirci Department of Pharmacognosy, Faculty of Pharmacy, Anadolu University, 26470-Eskisehir, Turkey E-mail: khcbaser@anadolu.edu.tr Dedicated to Professor Atta-Ur-Rahman on the occasion of his 65th birthday Abstract Essential oils were obtained from leaf, branch and buds of Betula species: B. pendula Roth, B. browicziana A.Güner, B. litwinowii Doluch., B. recurvata V. Vassil., and B. medwediewii Regel naturally growing in various parts of Turkey. Also buds of the common birch B. pendula essential oil from Germany and two species native to Finland namely, Betula pubescens ssp. czerepanovii (Orlova) Hämet-Ahti and Betula pubescens ssp. pubescens Erhr. were investigated. Betula essential oils were obtained by different distillation techniques such as hydrodistillation, microdistillation and Likens-Nickerson simultaneous distillation-extraction method (SDE). The resulting volatile compositions were elucidated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) systems. Known and new sesquiterpenes were isolated from Betula essential oils using column chromatographic techniques. Structure determination of each isolated compound was carried out using 1D and 2D NMR spectroscopic techniques supported by MS, UV and GC FITR. Biological activities were determined both for essential oils and pure compounds isolated from the oils of Betula species. Antifungal, antibacterial and antioxidant activity results were carried out using various in vitro techniques. Keywords: Betulaceae, Betula species, Birch tree, essential oil, sesquiterpenes, caryophyllene, chromato-spectral techniques, biological activity Introduction Well-known as birch tree, the genus Betula of the family Betulaceae, has a wide distribution in the northern hemisphere from Canada to Japan.1 Five Betula species, namely B. browicziana A. Güner, B. litwinowii Doluch., B. medwediewii Regel, B. pendula Roth and B. recurvata V. Vassil are naturally growing in eastern and northern Turkey, at high altitudes. Only B. browicziana is endemic to Turkey.2,3 The Birch tree has a long history of medicinal use in different countries and cultures to cure skin diseases especially eczema, infections, inflammations, rheumatism and urinary disorders. ISSN 1424-6376 Page 335 ©ARKAT USA, Inc.
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