d-Limonene, a monoterpene, is widely distributed as a natural nonnutritive constituent of a variety of foods and volatile oils, particularly citrus oils. d-Limonene and its derived metabolites have been shown to possess cancer chemotherapeutic and chemopreventive efficacy in various preclinical model systems. In our previous work, we have found that lemonade prepared with the whole lemon (Medit...

Limonene, a monocyclic monoterpene, is present in orange peel and other plants and has been shown to have chemopreventive activities. (+)- and (-)-Limonene enantiomers were incubated with human liver microsomes and the oxidative metabolites thus formed were analyzed using gas chromatography-mass spectrometry. Two kinds of metabolites, (+)- and (-)-trans-carveol (a product by 6-hydroxylation) an...

This is the first on the modulation of norfloxacin antibiotic activity by the volatile compounds of an essential oil. We report the chemical composition and antibiotic modifying activity of the essential oil extracted from the leaves of Croton zehntneri Pax et Hoffm (variety estragole), using the minimal inhibitory dose method and gaseous contact. The leaves of Croton zehntneri Pax et Hoffm (Eu...

We cloned the gene of d-limonene synthase (ArLMS) from Agastache rugosa (Labiatae). The function of ArLMS was elucidated by the preparation of recombinant protein and subsequent enzyme assay. ArLMS consisted of 2077 nucleotides including 1839 bp of coding sequence that encodes a protein of 613 amino acids. This protein has a 60 kDa molecular weight, which is identical to that of d-limonene synt...

(+)-limonene is a lipophilic antimicrobial compound, extracted from citrus fruits' essential oils, that is used as a flavouring agent and organic solvent by the food industry. A recent study has proposed a common and controversial mechanism of cell death for bactericidal antibiotics, in which hydroxyl radicals ultimately inactivated cells. Our objective was to determine whether the mechanism of...

The essential oils of peppermint and spearmint are distinguished by the position of oxygenation on the constituent p-menthane monoterpenes. Peppermint produces monoterpenes bearing an oxygen at C3, whereas spearmint produces monoterpenes bearing an oxygen at C6. Branching of the monoterpene biosynthetic pathways in these species is determined by two distinct cytochrome P450s that catalyze the r...

Terpene composition of needle and cortical oleoresin from lateral shoots were analyzed by GC/MS for four Silver fir (Abies alba Mill.) populations scattered in natural species range in Albania. More than sixty compounds were detected in the needle oleoresin, which was characterized by a high content of alpha-pinene, camphene, beta-pinene, limonene and bornyl acetate. Three monoterpenes, alpha-p...

Terpenes are the major secondary metabolites produced by plants, and have diverse industrial applications as pharmaceuticals, fragrance, solvents, and biofuels. Cyanobacteria are equipped with efficient carbon fixation mechanism, and are ideal cell factories to produce various fuel and chemical products. Past efforts to produce terpenes in photosynthetic organisms have gained only limited succe...

We studied the effects of natural essential oil on neurite outgrowth in PC12m3 neuronal cells to elucidate the mechanism underlying the action of the oils used in aromatherapy. Neurite outgrowth can be induced by nerve growth factor (NGF), where ERK and p38 MAPK among MAPK pathways play important roles in activating intracellular signal transduction. In this study, we investigated whether d-lim...