Essential oils are complex natural mixtures, their main constituents, e.g. terpenes and phenylpropanoids, being responsible for their biological properties. Essential oils from eucalyptus, tea tree and thyme and their major monoterpene compounds alpha-terpinene, gamma-terpinene, alpha-pinene, p-cymene, terpinen-4-ol, alpha-terpineol, thymol, citral and 1,8-cineole were examined for their antivi...

Rate constants for the gas phase reactions of O(P) atom with a series of monoterpenes have been determined at ambient temperature (~302-309K) and atmospheric pressure using a relative rate technique. Using the literature rate constants for O(P) + isobutene, cis and trans-2-butene, 3-methyl-1-butene, 2-methyl-2-butene and 2,3-dimethyl-2-butene as the standards, the O(P) rate constants derived fo...

AIMS To investigate the in vitro antiviral activity of Melaleuca alternifolia essential oil (TTO) and its main components, terpinen-4-ol, alpha-terpinene, gamma-terpinene, p-cymene, terpinolene and alpha-terpineol. METHODS AND RESULTS The antiviral activity of tested compounds was evaluated against polio type 1, ECHO 9, Coxsackie B1, adeno type 2, herpes simplex (HSV) type 1 and 2 viruses by ...

This in vitro study aimed at estimating the disappearance rates of 14 terpenes and terpenoids after 24-h incubation with mixed bacteria from caprine rumens. These compounds comprised nine monoterpene hydrocarbons (δ-3-carene, p-cymene, β-myrcene, (E)- and (Z)-β-ocimene, α-phellandrene, α-terpinene, γ-terpinene and α-terpinolene), four oxygenated monoterpenes ((E)- and (Z)-linalool oxide, 4-terp...

OBJECTIVE The aim of this study was to evaluate the antioxidant and anti-inflammatory activities of Plai oil-encapsulated niosomes (Zingiber cassumunar Roxb.) on inflamed subcutaneous Wistar rat skin by therapeutic ultrasound. METHODS Pure oil from Plai rhizomes was extracted by steam distillation, and antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging ...

In Experiment 1, four normosmics and four anosmics (three congenital, one idiopathic) provided odor and nasal pungency thresholds, respectively, for the following terpenes: delta3-carene, p-cymene, linalool, 1.8-cineole, and geraniol, plus the structurally related compound cumene. Additionally, all subjects provided nasal localization (i.e., right/left) and eye irritation thresholis. Trigeminal...

The compositions of essential oils (EOs) from Spanish marjoram (Thymus mastichina L.) grown in several bioclimatic zones of Murcia (SE Spain) were studied to determine their absolute and relative concentrations using gas chromatography-mass spectrometry. 1,8-Cineole and linalool were the main components, followed by α-pinene, β-pinene and α-terpineol. (-)-Linalool, (+)-α-terpineol and (+)-α-pin...

acetylcholinesterase properties of the aerial parts and roots essential oils from Crithmum maritimum L., Apiaceae, gathered in the area of Monastir (Tunisia). The essential oils have been analysed by GC and GC-MS. Remarkable differences were found between the constituent percentages of the different studied organs. The most important compounds from the aerial parts were: γ-terpinene (39.3%), me...

Compositional changes of Citrus tamurana Hort. ex Tanaka (hyuganatsu) essential oil were analyzed after storage for 1, 3, 6, and 9 weeks at -21, 5, 20, and 30 degrees C. The total amount of oxides increased greatly. The contents of monoterpene alcohols and ketones also increased. The total amount of monoterpene hydrocarbons was unchanged up to 30 degrees C. However, the contents of myrcene, gam...

The aerial parts of Pituranthos tortuosus (Desf.) Benth and Hook (Apiaceae), growing wild in Egypt, yielded 0.8%, 0.6%, and 1.5% (v/w) of essential oil when prepared by hydrodistillation (HD), simultaneous hydrodistillation-solvent (n-pentane) extraction (Lickens-Nickerson, DE), and conventional volatile solvent extraction (preparation of the "absolute", SE), respectively. GC-MS analysis showed...