Elsevier

Phytochemistry

Volume 65, Issue 14, July 2004, Pages 2045-2049
Phytochemistry

Sesquiterpenes from the east African sandalwood Osyris tenuifolia

https://doi.org/10.1016/j.phytochem.2004.05.007Get rights and content

Abstract

The essential oil of the east African sandalwood Osyris tenuifolia was investigated by chromatographic and spectroscopic methods. Beside several already known sesquiterpenes four new compounds could be isolated by preparative gas chromatography and their structures investigated by mass spectroscopy and NMR techniques. Two of the new compounds – tenuifolene (17) and ar-tenuifolene (15) – show a new sesquiterpene backbone. 2,(7Z,10Z)-Bisabolatrien-13-ol (23) and the cyclic ether lanceoloxide (21) belong to the bisabolanes.

The essential oil of East African sandalwood Osyris tenuifolia was investigated by NMR, Mass spectrometry and chemical correlations. Four new sesquiterpenes including 15 and 17 with a new skeleton were identified.

  1. Download : Download full-size image

Introduction

Osyris tenuifolia (East African sandalwood) belongs taxonomically to the Santalaceae. The small tree occurs in the equatorial region of Africa, where the extract of its small shoots is used as antipyretic agent by the Massai for cattle (Thanner, 1908). The essential oil of O. tenuifolia was investigated for the first time by Naves and Ardizio (1954), who could already identify the main constituent lanceol.

In the present work the essential oil of O. tenuifolia was analyzed by GC–MS. Four new sesquiterpenes – ar-tenuifolene (15), tenuifolene (17), 2,(7Z,10Z)-bisabolatrien-13-ol (23) and lanceoloxide (21) – could be isolated by preparative GC. The structures of the compounds were investigated by mass spectroscopy and NMR (1H, 13C, 1H–1H COSY, HMQC, HMBC and NOESY). Compounds 17 and 21 show a sesquiterpene backbone which is reported for the first time.

Section snippets

Results and discussion

The commercially available essential oil of O. tenuifolia shows a complex fraction of sesquiterpenoids. Most of the known compounds (1–14, 16 and 20) were identified by comparing their mass spectra and retention indices to a spectral library established under identical experimental conditions (Joulain and König, 1998). The already known sesquiterpenes epi-cyclosantalal (18) (Brunke and Vollhardt, 1995), (−)-epi-α-bisabolol (19) (Isaak et al., 1968; Kergomard and Veschambre, 1977), the main

Gas chromatography

Orion Micromat 412 double column instrument with 25 m fused silica capillaries with polysiloxane CPSil-5 and polysiloxane CPSil-19 (Chrompack); Carlo Erba Fractovap 2150 or 4160 gas chromatographs with 25 m fused silica capillaries with octakis(2,6-di-O-methyl-3-O-pentyl)-γ-cyclodextrin, heptakis(2,6-di-O-methyl-3-O-pentyl)-β-cyclodextrin or heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-β-cyclodextrin in OV 1701 (50%, w/w), split injection; split ratio approx. 1:30; FID; carrier gas 0.5

Acknowledgements

We gratefully acknowledge financial support of “Fonds der Chemischen Industrie”. We although thank Dr. V. Sinnwell, University of Hamburg, for his support in recording the NMR spectra and Mrs. A. Meiners and Mr. M. Preusse for GC–MS measurements.

References (9)

There are more references available in the full text version of this article.

Cited by (29)

  • Five new agarofuran sesquiterpene polyesters from Osyris lanceolata

    2013, Phytochemistry Letters
    Citation Excerpt :

    Despite its widespread use in traditional medicine, however, very limited phytochemical studies have been carried out on O. lanceolata in particular. There was only one previous study reported by Kreipl and Konig (2004) in which 23 sesquiterpenes were identified by GC–MS analysis from the essential oil of the dry wood of O. tenuifolia which is a synonym of O. lanceolata (African Flowering Plants Database, 2013). There were no reports in the literature on the chemical constituents of the roots, bark or leaves of O. lanceolata.

  • Sandalwood fragrance biosynthesis involves sesquiterpene synthases of both the terpene synthase (TPS)-a and TPS-b subfamilies, including santalene synthases

    2011, Journal of Biological Chemistry
    Citation Excerpt :

    This suggests factors controlling the spatial or temporal patterns of TPS expression, rather than the absence of, or mutations in the ORFs of the genes themselves, are likely to be responsible for the low- or no-oil phenotype. All oil producing species of Santalum, and even ancestral genera within the Santalaceae family (36), contain detectable levels of the santalenes, α-bergamotene, bisabolene, and bisabolol, and all species studied here contain complete genomic copies of the santalene synthase ORF. The uniformity of santalene product profiles of SaSSy, SauSSy, and SspiSSy is in contrast to the variety of compounds produced by the bisabolene/bisabolol synthases, and more so by the TPS-a group sesquiterpene synthases in the Santalum genus.

View all citing articles on Scopus
View full text