M.Tech. / There are over 250 cinnamon species existing worldwide, and amongst them, 2 species Cinnamomum cassia and Cinnamomum zeylanicum, are commonly used all over the world as spices, fragrances in perfumes and as medicines. These two species are distinguished from each other by the presence and absence of certain compounds depending on the origin and distribution of the plant. Nevertheless, all cinnamon species contain essential oils and water soluble components and the composition of these components found in each species depends on the type of species involved. These components are made up of phenyl propanoids, terpenes, flavonoids and saponins. In general, the essential oil component contains the following compounds: cinnamaldehyde as a major constituent with its derivatives cinnamic acid, cinnamyl alcohol, ethyl cinnamate, cinnamyl acetate and 2-methoxy cinnamaldehyde; eugenol; linalool; coumarin; carvone; carvacrol and β-caryophyllene. Most of these compounds are abundantly found in the bark except in the case of eugenol which is found in either leaves or bark depending on the species involved. The other water soluble component is composed of a group of compounds such as tannin, chalcone, catechins and anthocyanidins. These compounds polymerize to form methyl hydroxy chalcone polymers (MHCP) which has been shown to play an important role in lowering blood sugar levels in Type ll diabetic individuals. It is said that MHCP has an ability to promote the phosphorylation process which in turn activates the beta-cells and thereby creating insulin activity that will then convert glucose into glycogen. Besides all health benefits of cinnamon, the plant contains a toxic compound, coumarin which impacts badly on animals resulting in death, and little information on its toxicity to human beings has been documented. Concerns arose about the possible presence of coumarin in these formulations, since these formulations are made from the cinnamon and the plant contains coumarin. This work has investigated the potential toxicity of coumarin from cinnamon powder and cinnamon formulation. The components from both cinnamon samples were extracted using various solvents according to their polarities and these compounds were screened on thin layer chromatography (TLC). The essential oil components were separated by column chromatography, and quantified by using high performance liquid chromatography (HPLC), all components (essential oil and water soluble) were identified by HPLC, and finally the characterization of the essential oil components was done with infrared (IR) and nuclear magnetic resonance (NMR) whereas those of the water soluble were characterized by using liquid chromatography coupled to a mass spectrometer (LC-MS).