Thermal, photo-oxidation and antimicrobial studies of linalyl acetate as a major ingredient of lavender essential oil

Abstract

Lavender oil, obtained from the flowers of Lavandula angustifolia (Family: Lamiaceae) by steam distillation, The major component of lavender oil is linalyl acetate was isolated and subjected to oxidation thermally and photochemically using (mcpba and H2O2) respectively to produce mixture of 6,7-epoxy-3,7-dimethyl-1-octene-3-yl acetate (3) and 1,2-epoxy-3,7-dimethyl-6-octene-3-yl acetate (4) photochemically, while produced epoxide 4 only thermally. On the other hand, photooxygenation of 1 using different singlet oxygen sensitizers gave two hydroperoxide derivatives of 6-hydroperoxy-3,7-dimethylocta-1,7-diene-3-yl acetate (5) and 7-hydroperoxy-3,7-dimethylocta-1,5-diene-3-yl acetate (6) in the presence of tetraphenyl porphin (TPP), whereas gave hydroperoxide 6 only using hematoporphyrin (HP). Studies on the antimicrobial especially Microsporum canis and Microsprum gallinna showed that linalyl acetate and its epoxide and hydroperoxide derivatives have a good antibacterial action. Keywords: Medicinal plants, Monoterpene, Linalyl acetate, Essential oil, Epoxidation, Antibacterial, m-Chloroperbenzoic acid, Photooxygenation, Epoxide