Seasonal Variation of Essential Oil Yield and Composition ofThymus hyemalis

Abstract

The aerial parts of THYMUS HYEMALIS Lange were collected throughout its complete vegetative cycle (April 1981 to March 1982) from the same locality. The yield and composition of essential oil have been determined in eleven samples with special reference to the content of 1,8-cineole, camphor, thymol, and carvacrol. It was found that the yield and composition of the oil changed from month to month. On the basis of the results obtained, July might be proposed as the most suitable month for harvesting T. HYEMALIS, giving the maximum yield in essential oil, which is especially rich in terpenic hydrocarbons at this time. Maximum levels of 1,8-cineole in August, however, might warrent harvesting during this month as well.

Comparison of ohmic-assisted hydrodistillation with traditional hydrodistillation for the extraction of essential oils from Thymus vulgaris L.

“…Golmakani and Rezaei extracted essential oils from thyme with HD and reported the yield of 2.39% (wt.%). Cabo et al (1987) collected the aerial parts of Thymus hyemalis Lange throughout its complete vegetative cycle and reported that the essential oil content varying from 0.15% on December 23 to 0.58% on July 4 of the next year. Similar results were reported for T. vulgaris L. (2-and 5-year old plants) (Hudaib, Speroni, Di Pietra, & Cavrini, 2002).…”

“…23). The essential oil composition of T. vulgaris can be influenced by harvest time, ecological and climatic conditions (Cabo et al, 1987;Putievsky & Basker, 1977). Many authors have reported that T. vulgaris oil components change by different ecological regions, growing conditions, harvest time and years (Baranauskiene et al, 2003;Kastner, 1969;Özgüven & Stahl-Biskup, 1989;Özgüven & Tansi, 1998;Piccaglia & Marotti, 1991).…”

Essential oil composition, phenolic content, antioxidant, and antimicrobial activity of cultivatedSatureja rechingeriJamzad at different phenological stages

“…Essential oil constituents and secondary metabolites in medicinal and aromatic plants are strongly influenced by their origin, environmental conditions, ontogenetic variation [11,12], management practices (e.g., harvest time), and ecological and climatic conditions [13]. Therefore, antimicrobial, antioxidant, and other biological activities may vary, based on the variations in chemical compositions of essential oils and the extracts of medicinal plants [14][15][16].…”

“…b Minimum inhibitory concentration, values as mg/mL. c Oxa: oxacillin (1 μg/disk), Tet: tetracycline (30 μg/disk); Amox: amoxicillin (10 μg/disk); Keto: ketoconazol (20 μg/disk); Gen: gentamicine (30 μg/disk);(7)(8)(9)(10)(11)(12)(13)(14), moderately active; ( > 14), highly active; NA, not active. to you by | Dalhousie University Authenticated Download Date | 6/22/15 10:13 PM…”

Essential Oil Composition, Total Phenolic Content, Antioxidant Activity and Antifungal Properties of IranianThymus daenensissubsp.daenensisCelak. as in Influenced by Ontogenetical Variation

“…These compounds can delay or inhibit the oxidative damage caused by free radicals and can protect us against major diseases such as coronary heart disease and cancer in human 9,[13][14][15][16] . The yield of plant material, essential oil composition and secondary metabolites in medicinal and aromatic plants are strongly influenced by harvest time, ontogenetical variation and environmental factors such as soil type and nutriton 9,[17][18][19] . Knowledge of the factors that influence on yield and essential oil composition in medicinal plants is insufficient, and these factors seems to play a important role in drug yield and essential oil composition in medicinal and aromatic plants.…”