The p-menthane monoterpenes of the Mentha species are biosynthesized from geranyl pyrophosphate via the monocyclic olefin 4S-limonene. A monoterpene cyclase was isolated from both Mentha x piperita (peppermint) and Mentha spicata (spearmint) that catalyzes the cyclization of geranyl pyrophosphate to 4S-limonene. This enzyme, 4S-limonene synthase, was purified to apparent homogeneity by dye liga...

Extracorporeal shockwave lithotripsy (ESWL) of gall bladder stones leaves residual fragments that need to be dissolved by chemical solvents. In this study we compared the in vitro dissolving capacity of methyl tert-butyl ether (MTBE), mono-octanoin, limonene, and limonene/mono-octanoin (70%/30%). From nine sets of five human gall stones obtained at cholecystectomy, four stones were used for dis...

Plant essential oils (EOs) and a wide range of their individual components are involved in a variety of biological interactions with insect pests including stimulatory, deterrent, toxic and even hormetic effects. Both the beneficial and toxic properties of citrus EOs on the Mediterranean fruit fly (medfly) have been experimentally evidenced over the last years. However, no information is availa...

An improved method of sample preparation was used in a microplate assay to evaluate the bactericidal activity levels of 96 essential oils and 23 oil compounds against Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica obtained from food and clinical sources. Bactericidal activity (BA50) was defined as the percentage of the sample in the assay mixture...

objective: some evidence suggests that chronic uptake of estragole and methyl-eugenol, found in the essential oil of artemisia dracunculus (tarragon), may be associated with an increased risk of hepato-carcinogenicity. the present study was conducted to investigate the immumodulatory and anti-inflammatory potentials of estragole and methyl-eugenol free extract of tarragon. materials and methods...

The pollination process in oil palm is assisted by the insect Elaeidobius kamerunicus, which occurs when male and female flowers bloom producing volatile compounds that act as attractants. This study aims to identify based on differences times with gas chromatography mass spectrometry (GC-MS). research steps include determining time of release flowers, extracted using steam distillation, identi...

The isomerization of estragole to trans-anethole is an important reaction and is industrially performed using an excess of NaOH or KOH in ethanol at high temperatures with very low selectivity. Simple Ru-based transition-metal complexes, under homogeneous, ionic liquid (IL)-supported (biphasic) and "solventless" conditions, can be used for this reaction. The selectivity of this reaction is more...

BACKGROUND The burden of liver disease in the UK has risen dramatically and there is a need for improved diagnostics. AIMS To determine which breath volatiles are associated with the cirrhotic liver and hence diagnostically useful. METHODS A two-stage biomarker discovery procedure was used. Alveolar breath samples of 31 patients with cirrhosis and 30 healthy controls were mass spectrometric...

The work presented in this thesis aims to improve the possibilities for diagnosing contact allergy to oxidized limonene and linalool and to, in patients, study contact allergy from structurally closely related hydroperoxides with regard to their specificity, potency and cross-reactivity. The fragrance terpenes limonene (from citrus oil) and linalool (from lavender oil) are widely used in househ...