This is a refereed journal and all articles are professionally screened and reviewed ORIGINAL ARTICLE Advances in Environmental Biology, 4(2): 250-253, 2010 ISSN 1995-0756 © 2010, American-Eurasian Network for Scientific Information 250 Corresponding Author: Hamid A.A., Department of Chemistry, University of Ilorin, P.M.B 1515, Ilorin, Kwara State, Nigeria. Tel. +2340735931646; E-mail: hamidmemo@yahoo.com, Chemical Constituents of Leaf Essential Oil of North-central Nigerian Grown Vitex Agnus-castus l Hamid A.A., Usman L.A., Adebayo S.A., Zubair M.F., Elaigwu, S.E., Department of Chemistry, University of Ilorin, P.M.B 1515, Ilorin, Kwara State, Nigeria. Hamid A.A., Usman L.A., Adebayo S.A., Zubair M.F., Elaigwu, S.E., Chemical Constituents of Leaf Essential Oil of North-central Nigerian Grown Vitex Agnus-castus l: Adv. Environ. Biol., C(): CC-CC, 2010 ABSTRACT Pulverized leaf of vitex agnus-castus on hydrodistillation, afforded oil in the yield of 0.8%v/w. GC, GC/MS analyses of the oil revealed the abundance of hydrocarbon and oxygenated monoterpenes (53.2 and 24.5% respectively). The major constituents of the oil were; ȕ-pinene (20.0%), viridiflorol (9.8%), α-pinene (9.1%), cis- ocimene (8.4%), 1,8-cineole (6.7%), ȕ-farnesene (5.4%), terpinen-4-ol (4.2%), α-terpineol (4.1%) and ȕ-phellandrene (4.1%). Key words: Vitex agnus-castus, verbenaceae, ȕ-pinene, α-pinene, cis-ocimene, viridiflorol and 1,8-cineole. Introduction Vitex agnus-castus L. (Verbenaceae) is a perennial grey shrub, with a strong aromatic odour [1]. It is grown as ornamental plant in Nigeria and in different parts of the world. The plant is used in folk medicine for the treatment of premenstrual syndrome (PMS), gynecological and digestive complaints, infertility, stomachache, headache, influenza, diarrhea and syphilis [2-11].It is also used as carminative, antiseptic, a diuretic and an anaphrodisiac [7,9]. The various biological activities of the plant such as immunodulatory, antimicrobial and antioxidant properties justified its use in traditional medicine [12- 14]. The insecticidal property of the plant has also been reported [15]. Phytochemical studies of the plant revealed the presence of casticin, eupatorin, penduletin, vitexin, orientin, vitetrifolin B and C, rotundifuran, vitexilactone and spathulenol [12-14]. Earlier work on leaves, inflorescences and fruits essential oils of vitex agnus- castus grown in Southern Italy has led to the identifications of 1,8-cineole, α-terpineol, sabinene, ȕ- selinene, ȕ-caryophyllene and cis-ȕ-farnesene as the main constituents of the oils [16]. Sabinene, ȕ- farnesene and 1,8-cineole were the most abundant constituents of the leaf, flower and fruit essential oils of North Brazilian grown V.agnus-castus [17]. α- pinene, ȕ-pinene, limonene, sabinene, 1,8-cineole and terpineol were identified as the principal constituents of the leaf oil of South-west Nigerian grown V.agnus- castus [13]. In continuation of our studies of essential oil from medicinal plants used in folk medicine in North-central Nigeria, we investigated the leaf essential oil of Vitex agnus-castus.