Chemotype of Litsea cubeba Essential Oil and Its Bioactivity Syaliza Abdul Hammid* and Fasihuddin Ahmad Department of Chemistry, Faculty of Resource Science and Technology, University Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia syalizaham@yahoo.com.my Received: January 26 th , 2015; Accepted: April 21 st , 2015 The essential oils from different parts of Litsea cubeba, collected from the highlands of Sarawak, were isolated and their chemical compositions analyzed. This study demonstrated significant variations in the chemical compositions and the chemical profiles of the volatiles and could provide valuable supplementary information on the geographical variations of the species. The fruit essential oil was dominated by citronellal, d-limonene and citronellol, while the leaf oil was high in eucalyptol and α-terpineol. High concentrations of citronellal and citronellol in both the root and bark oils were identified. In the stem, the oil was dominated by eucalyptol, d-limonene and α-terpineol. The activity of the oils against brine shrimp larvae, bacteria, yeast and fungi was determined. The oils were toxic against brine shrimp larvae with LC 50 values ranging from 25.1 – 30.9 μL/mL. The oils also demonstrated a wide spectrum of inhibition against microorganisms with inhibition zones between 19.5 – 46.7 mm against Gram-positive bacteria and 10.5 – 90.0 mm against yeast and fungi. However, the oils were not active against Gram-negative bacteria. Keywords: Litsea cubeba, Essential oil, Chemotype, Cytotoxic activity, Antimicrobial. Litsea cubeba Pers., family Lauraceae family, is distributed in southern China, Japan and Southeast Asia, and the mountain areas of Taiwan, Thailand, northeast India, Korea, Vietnam and Indonesia [1,2,3]. In Sarawak, L. cubeba is known as Pahkak by the Bidayuh community in Kiding and Tenom in Lawas [4]. It is a small tree growing wild in the mountain areas of Sarawak, such as Padawan and Bario [5]. L. cubeba is known for its pleasant aroma and traditional usage. It is cultivated for its essential oil for the perfume industry, for feeding muga silk worms, to produce fast-growing timber, aromatherapy [6], treatment of disease [7], paint industry, resin varnish, plastic and biodiesel [8]. In Sarawak, the fruits are used as a flavor enhancer and for treatment of stomach ache [4]. Various studies on the fruit oils of L. cubeba collected from China, Taiwan, Vietnam, India and Thailand have shown citral as the main component [1, 2, 9-12]. A recent study reported an additional chemotype, whereby the fruit oil was dominated by 70% citronellol with 10% of citronellal [13]. Several variations of the chemical composition of the leaf oil have been reported. The Chinese leaf oil consisted of a high percentage of α-cis-ocimene, β-phellandrene [14], citronellal [15] and citral [11]. In India, sabinene-rich [13] and linalool-rich [14] leaf oils were identified. A study of Vietnam leaf oils collected from six provinces showed variation of chemical composition [15]. According to Bighelli et al. [15], the leaf oil was dominated by eucalyptol (range 0.2-51.7%), linalool (range 0.4-91.1%) and sabinene (range 0-48.1%). Eucalyptol was the dominant compound in the leaf oil collected from Indonesia, China and Taiwan [16-20]. In West Java, the leaf oil was characterized by eucalyptol and citral [9]. Stem bark oil of northeastern India was rich in citronellol, linalool and citronellal [18] while eucalyptol (26.6%), citronellol (21.7%), linalool (9.9%) and citronellal (8.7%) were reported in oils from Indonesia [20]. In China, the stem oil was predominant in β-phellandrene [21] A study of the root oil reported citronellal [22] and citral as the main components [11, 21]. Pharmacological studies indicated that the essential oil of L. cubeba possessed antispasmodic, bronchodilator, antimicrobial, antioxidant, antiparasitic, acute and genetic toxicity, cytotoxic and anticancer activities [9, 21-24]. The oil was also a potential insecticide and able to repel cabbage looper, Trichoplusia ni, Japanese termite, Reticulitermes speratus, mosquito, Aedes aegypti, maize weevil, Sitophilus zeamais, redflour beetle, Tribolium castaneum, nematode, Bursaphelenchus xylophilus, cigarette beetles, Lasioderma serricorne, and booklouse, Liposcelis bostrychophila [1, 2, 25-27]. L. cubeba has been well investigated from a phytochemical point of view and for its bioactivity properties. However, there is no published study on the chemical composition and bioactivity of L. cubeba essential oil from Sarawak. Therefore, this study was carried out to determine the quantitative and qualitative composition of the essential oil from different organs of L. cubeba collected in Sarawak, and to investigate the essential oils for their antimicrobial and cytotoxic activities. Essential oil composition: Hydro-distillation of L. cubeba gave clear and light yellow oil in yields ranging from 0.4% - 12.0%, v/w, on a dry weight basis, for different plant parts. The leaf oil was obtained in a yield of about 8.1%, while an average of 1.8% and 0.7% were recovered, respectively, from the bark and the root of the plant. The lowest oil yield was obtained from the stem (0.4%). A previous study reported that the fruit of L. cubeba (May Chang) gave 3-8% yield of oil using steam distillation [4]. The volatile components of the essential oil samples were analyzed using GC-MS and the results are presented in Table 1. A total of 15 compounds were identified in the fruit essential oil, which showed monoterpenes (92.9%) as the dominant group; citronellal (51.5%), d-limonene (10.4%) and citronellol (8.9%) were the major components. This result supported the findings of the previous study [4]. The strong smell of the fruit oil could be related to the presence of a high percentage of citronellal. Only a small percentage of sesquiterpenes (5.8%) and citral (2.6%) were present in the fruit oil. A citronellal-rich fruit oil was also found in the NPC Natural Product Communications 2015 Vol. 10 No. 7 1301 - 1304