Olawore et al. 604/Journal of Essential Oil Research Vol. 18, November/December 2006 Received: December 2004 Revised: February 2006 Accepted: March 2006 Constituents of Rhizome Essential Oils of Two Types of Cyperus articulatus L. Grown in Nigeria Nureni O. Olawore* and Lamidi A. Usman Department of Pure and Applied Chemistry, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, 210001, Nigeria Isiaka A. Ogunwande Department of Chemistry, University of Ibadan, Ibadan, Nigeria Kasali A. Adeleke Department of Chemistry, Lagos State University, Ojo, Lagos, Nigeria Abstract The essential oils of the rhizomes of the red and black types of Cyperus articulatus L. were investigated by GC and GC/MS. Oxygenated sesquiterpenes constituted the bulk of both oils (54.2% and 52.1% for the red and black types, respectively). The major components of the oil of the red type were cyperotundone (42.3%), piperitone (10.1%), β-maaliene (8.4%) and germacrone (5.3%), while the oil of the black type had an abundance of cedrol (19.0%), guaia- 5-en-11-ol (14.9%) and cyperotundone (9.6%). Key Word Index Cyperus articulatus, Cyperaceae, essential oil composition, cyperotundone, piperitone, cedrol, guaia-5-en-11-ol. 1041-2905/06/0006-0604$14.00/0—© 2006 Allured Publishing Corp. J. Essent. Oil Res., 18, 604-606 (November/December 2006) *Address for correspondence Introduction Cyperus articulatus L. (family Cyperaceae) is tropical sedge widely grown in Nigeria, where it is commonly known as ‘kajiji’ by the Hausas, ‘woire’ by the Fulanis and ‘ifin’ by the Yorubas (1). The plant is used in traditional medicine for the treatment of several ailments like epilepsy, malaria and dysentery in dif- ferent parts of the world (1). The therapeutic properties of this plant have been established by various workers. For instance, the non-volatile extracts of the rhizomes of C. articulatus are known to possess anticonvulsant, anti-malaria and antimicrobial properties (2-4). Repellant and anti-feedant properties of these extracts have also been reported (5). Nyasse et al. (6,7) have isolated the sesquiterpenic ketones, mandassidione, mustakone, corymbolone and the alcohol corymbolol, from Cameroonian grown C. articulatus. Earlier work on the essential oils from the Canadian grown C. articu- latus has led to the isolation and characterization of a bicyclic ketone, articulone, which was later, renamed cyperotundone and isopatchoul-4(5)en-3-one (8). Literature information is scant on the chemical composition of the oil from C. articulatus. However, research works on the oil composition of other Cyperus species have been reported. Ekundayo et al. (9) had reported that the main constituents of the essential oil of C. tuberosus were α-humulene (30.04%), humulene epoxide II (16.91%), β-caryophyllene (12.13%) and caryophyllene oxide (10.75%), while C. rotundus L. had cyperene (19.19%) and α-cyperone (17.72%) in abundance. On the other hand, Sonwa and Koenig (10) had isolated (-) nor-rotundone, (-)-isorotundone, (-)-cypera-2,4(15)-diene and (+)-cyperadione from C. rotundus. In continuation of our systematic study of the essential oils of Nigerian medicinal plants, we investigated the rhizome oils of the red and black types of C. articulatus. Experimental Plant materials: The dried rhizomes of the red and black types of C. articulatus were obtained in Ilorin, Kwara State, Nigeria. Identification was carried out at the herbarium of the Forestry Research Institute of Nigeria (FRIN), Ibadan, where voucher specimens were deposited. Oil isolation: Pulverized rhizomes of the red and black types of C. articulatus (500 g) were separately hydrodistilled for 3 h in a Clevenger-type apparatus, according to the Brit- ish Pharmacopoeia specification (11). The resulting oils were collected, preserved in a sealed sample tube and stored under refrigeration until analysis. Gas chromatography: GC analyses were performed on an Orion micromat 412 double focusing gas chromatography system fitted with two capillary columns coated with CP-Sil 5 and CP-Sil 19 (fused silica, 25 m x 0.25 mm, 0.15 µm film