1241 Research Article Received: 28 December 2008 Revised: 27 February 2009 Accepted: 2 March 2009 Published online in Wiley Interscience: (www.interscience.wiley.com) DOI 10.1002/jsfa.3582 Chemical composition and insecticidal properties of Cinnamomum aromaticum (Nees) essential oil against the stored product beetle Callosobruchus maculatus (F.) Rezuanul Islam, a,b Rejaul Islam Khan, b Sharif M Al-Reza, a Yong Tae Jeong, a Chi Hyun Song a and M Khalequzzaman c* Abstract BACKGROUND: Cinnamomum aromaticum is a widely used cooking ingredient in South Asian countries. In this study the essential oil of C. aromaticum was tested against the stored product beetle Callosobruchus maculatus. The objective was to identify the natural compounds with insecticidal properties in the essential oil of C. aromaticum with a view to its potential use as an alternative to synthetic pesticides. RESULTS: The chemical composition of the hydrodistilled bark essential oil of C. aromaticum was analysed by gas chromatography/mass spectrometry, and cis-cinnamaldehyde (53.90%) was found to be the principal constituent. The surface film and fumigation toxicities and repellency activity against C. maculatus were evaluated. The extracted oil showed 94.44% mortality against adult C. maculatus through the surface film bioassay. The LD 50 values were 27.56 and 23.16 μg cm -2 after 24 and 48 h of exposure respectively. The regression equations were calculated as Y = 0.39 + 3.20X and Y = 1.25 + 2.75X respectively. In the fumigation bioassay the LD 50 value was 434.69 μg cm -2 after 24 h of exposure, with the regression equation Y = 0.87 + 1.57X . It was also found that the extracted oil contained compounds that had a dose-dependent protective effect on egg hatching and adult emergence. CONCLUSION: The results obtained from this study suggest that the toxicity and insecticidal activity of C. aromaticum are attributable to its essential oil, which could be used as a biodegradable and natural bioprotectant for controlling stored product pests. c  2009 Society of Chemical Industry Keywords: essential oil; Cinnamomum aromaticum; Callosobruchus maculatus; insecticidal activity; cinnamaldehyde INTRODUCTION The genus Cinnamomum comprises about 250 species distributed throughout Asia and Australasia. 1 Different varieties of cinnamon oil contain cinnamaldehyde, eugenol, cinnamic acid, cinnamyl acetate, benzaldehyde, methyl salicylate, hydrocinnamaldehyde, o-methyl-coumaraldehyde, salicyaldehyde, cuminaldehyde, α- pinene, 1,8-cineol, linalool and α-terpineol. 2 The leaf essential oil of Cinnamomum osmophloeum grown in Taiwan contained mainly trans-cinnamaldehyde (79.85%) and showed excellent antibacterial, antitermite, antimite, antimildew, antipathogenic, antifungal and anti-inflammatory activities. 3–5 The bark essential oil of Cinnamomum zeylanicum contained 13 compounds, with (E)- cinnamaldehyde as the major component along with δ-cadunene (0.9%), α-copaenene (0.8%) and α-amorphene (0.5%). 6 The major components of cinnamon leaf grown in Little Andaman, India were eugenol (76.6%), linalool (8.5%) and pipertone (3.3%), 7 whereas the stem-distilled volatile oil of cinnamon fruit grown at Karnataka and Kerala, India consisted of hydrocarbons (32.8 and 20.8% respectively) and oxygenated compounds (63.7 and 73.4% respectively), with trans-cinnamyl acetate and β -caryophyllene as major components. 8,9 The search for new strategies or natural products to control destructive insect pests and vectors of diseases is desirable owing to the prevalent occurrence of vector resistance to synthetic insecticides and the problem of toxic non-biodegradable residues contaminating the environment and having undesirable effects on non-target organisms. 10,11 The practice of adding a little vegetable oil to stored rice or legumes for protection against insect pests is well known and well established in oriental countries such as China, ∗ Correspondence to: M Khalequzzaman, Department of Zoology, Rajshahi University, Rajshahi 6205, Bangladesh. E-mail: kzaman@ru.ac.bd a Department of Biotechnology, Daegu University, Gyungsan City, Gyungbuk 712-714, Korea b Department of Biotechnology and Genetic Engineering, Islamic University, Kushtia 7003, Bangladesh c Department of Zoology, Rajshahi University, Rajshahi 6205, Bangladesh J Sci Food Agric 2009; 89: 1241–1246 www.soci.org c  2009 Society of Chemical Industry