FLAVOUR AND FRAGRANCE JOURNAL Flavour Fragr. J. 2003; 18: 387–389 Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ffj.1214 Copyright © 2003 John Wiley & Sons, Ltd. John Wiley & Sons, Ltd. Chemical composition of the leaf volatile oils of Callitris intratropica R. T. Baker & H. G. Smith from Nigeria LEAF VOLATILE OIL OF CALLITRIS INTRATROPICA Isiaka A. Ogunwande, 1 Nureni O. Olawore, 2 * Adeleke A. Kasali 3 and Wilfried A. König 4 1 Department of Chemistry, University of Ibadan, Ibadan, Nigeria 2 Department of Pure and Applied Chemistry, Ladoke Akintola University of Technology, PMB 4000, Ogbomoso, Nigeria 3 Department of Chemistry, Lagos State University, Ojo, Lagos, Nigeria 4 Institut für Organische Chemie, Universität Hamburg, Hamburg D-20146, Germany Received 3 October 2001 Revised 16 September 2002 Accepted 18 September 2002 ABSTRACT: The chemical composition of the leaf volatile oils of Callitris intratropica from two different regions in Nigeria were investigated by GC and GC–MS. The essential oils comprised mainly monoterpenoids (93.0 –95.9%), while sesquiterpenoids constituted the minor components (1.4 – 4.4%). The quantitatively significant constituents of the essential oils were α-pinene (35.9 –55.6%), limonene (21.6 –50.5%) and myrcene (6.0 –10.1%). Copyright © 2003 John Wiley & Sons, Ltd. KEY WORDS: Callitris intratropica R. T. Baker & H. G. Smith; Cupressaceae; leaves; essential oils; limonene; α-pinene; monoterpenes; sesquiterpenes Introduction Callitris intratropica R. T. Baker & H. G. Smith belongs to one of the three species in the white Cypress pine complex, family Cupressaceae, and is native to Northern Australia. 1 It has since been introduced into various parts of the world. Literature information is scanty on the chemical constituents of the volatile oil of C. intratropica. A series of known sesquiterpenes, including β-elemene, selina-4,11-diene, α-guaiene, α-guaioxide, β-selinene, α- selinene, α-bulnesene, α-guaiol, β-eudesmol, γ-eudesmol, bulnesol and sesquiterpene lactone dihydrocolumellarin (guainolide), were identified from a commercial sample of the essential oil of the plant from South Africa. 2 Also identified in the same investigation was a new compound whose structure was established to be (-)- eudesma-1,4(15),11-triene. 2 This paper reports, for the first time, the compre- hensive analysis of the essential oils from the leaves of C. intratropica growing in Ogbomoso (South West) and Kaduna (North Central), regions of Nigeria. Experimental Plant Samples Samples of the leaves of C. intratropica were collected from the Forestry Station, Forestry Research Institute of Nigeria (FRIN), Afaka, Kaduna, Nigeria, in June 2000, and from a location at Ogbomoso in December 2000. Mr Sylvester Boyi of FRIN, Kaduna, and Mr T. K. Odewo of FRIN’s Herbarium, Ibadan, authenticated the samples. Voucher specimens were deposited at the herbarium of FRIN Ibadan, Nigeria. The leaves were air-dried under a shade. Isolation of the Volatile Oil Pulverized air-dried samples (350 g) were subjected to hydrodistillation in a Clevenger-type apparatus in accord- ance with British Pharmacopoeia (BP) methods. 3 The distillation time was 4 h. GC Analyses The GC analyses were performed on an Orion Analytical Micromat 412 gas chromatographic (GC) system fitted with two capillary columns coated with CP-Sil 5 and * Correspondence to: N. O. Olawore, Department of Pure and Applied Chemistry, Ladoke Akintola University of Technology, PMB 4000, Ogbomoso, Nigeria. E-mail: nurelawore@yahoo.co.uk