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Sage (Salvia officinalis L.) is an important medicinal and aromatic plant, whose the volatile oil from the leaves are commonly used as a raw material in pharmaceutical and perfumery industries. In this study, the influences of the foliar applications of 24-epibrassinolide (BRs: 2.5, 3.0, and 3.5 µM) and paclobutrazol (PBZ: 17, 25, and 34 µM) as well as three moisture conditions (non-stress, slight water deficit stress, and mild water deficit stress) on the content and chemical compositions of the essential oil from the sage leaves were investigated. For evaluation of phytochemical characteristics, the essential oils were analyzed by GC-FID and GC/MS. Substantial effect of the foliar applications of BRs and PBZ under different moisture conditions on the quantity and quality of the essential oil of sage was found. The highest essential oil contents were recorded for sage plants treated with BRs at 3.5 µM under mild drought stress (0.79 mL/100 g dry matter) followed by PBZ at 17 µM under slight drought stress (0.72 mL/100 g dry matter). Using the BRs and PBZ foliar meaningfully enhanced biologically active substances, including 1,8-cineole, α-thujone, β-thujone, and camphor as the major constituents in the essential oil under different moisture conditions. In final, it can be concluded that the applied of the BRs and PBZ mitigate the reducing effects of water shortages on improve the quantity and quality yield of S. officinalis L. under drought stress. [ABSTRACT FROM AUTHOR]

Mountain fennel (Zaravschanicamembranacea) and Ferulagoangulata belonging to the Apiaceae family are important aromatic and spice plants in Iran, which the aerial parts of these herbs are used as flavoring agents in dairy foods. This investigation was devoted to the determination of total phenols and flavonoids contents of Z.membranacea and F.angulata after their extraction using three solvents (ethanol, n-hexane, and methanol), as well as the determination of the antioxidant and the antibacterial activities of all obtained extracts. The results indicated that methanol appeared the most effective solvent for polyphenols and flavonoids' extraction for both herbs. In fact, the highest total phenols and flavonoids contents among the six prepared extracts from two herbs were found in the methanol extract of Z.membranacea. The results indicated that the extracts of have diverse antioxidant capacities, however, the methanol extract of Z.membranacea exhibited the highest antioxidant activities by DPPH, FRAP and ABTS assays. Moreover, the antibacterial activity of different extracts was evaluated using the disk diffusion agar method against Salmonellaenterica and Pseudomonasaeruginosa, and Bacillussubtilis and Staphylococcusepidermidis. The highest inhibition zone was obtained from the methanol extract of Z.membranacea for four bacteria. Similarly, the maximum antibacterial activity (MIC) also was obtained from the methanol extract of Z.membranacea for four bacteria. Positive and significant correlations were noted between the phenolic and flavonoid contents and antioxidant activities by DPPH, FRAP, and TEAC assays. In conclusion, methanol was found to be the best solvent of choice for the extraction of phenolic and flavonoid compounds rich extracts with free radical scavenging and antibacterial activities. Further studies should focus on the isolation and identification of active secondary metabolites from the extracts from Iranian herbs. [ABSTRACT FROM AUTHOR]

Thymus daenensis Celak. is an aromatic herb used as a popular medicine and its natural products in the form of extracts and essential oil have significant economic values in Iran. We hypothesized that spraying plants grown under deficit irrigation system with chitosan can be considered as an applicable method to enhance essential oil and antioxidant activity in thyme. Response of thyme to three irrigation regimes including well-watered, moderate stress, and severe stress along with three levels of chitosan application rates 0, 200, and 400 μL L was evaluated in a 2-year study in 2014 and 2015. Drought stress condition significantly shortened phenologic stages, more specifically in the first (establishment) year. All growth parameters were reduced dramatically as drought stress intensified. Imposing even moderate stress reduced leaf area as much as 59 and 44% in the first year and the second year, respectively. Biomass yield of plants grown under severe drought stress decreased substantially, whereas essential oil content and the share of thymol in thyme oil which possesses the greatest degree of biological activity improved. Maximum oil yield (1.50 g plant) was obtained from plants under mild drought stress when sprayed with 400 μL L chitosan in the second year when plants were well-established. Foliar applications of chitosan reduced the adverse effect of water deficit on oil yield and improved thymol content of the essential oil. Chitosan also increased secondary metabolites including α-terpinene, p-cymene, γ-terpinene, thymol, carvacrol and β-caryophyllene. Leaf flavonoid reduced under deficit irrigation while more phenol was found in plants grown under deficit irrigation. The essential oil of thyme exhibited antioxidant property when the plants were sprayed with 400 μL L chitosan. The results of this study indicated that thyme can be grown successfully under moderate stress and that application of chitosan elicitor can to some degree compensate the negative impact of deficit irrigation on its biomass and essential oil yield. [ABSTRACT FROM AUTHOR]

Myrtle, Myrtus communis L. (Myrtaceae), an evergreen shrub also known as wild myrtle, has a history of use as a culinary and medicinal plant. To determine the diversity within the species, plant leaves of myrtle were collected in 12 natural habitats in Iran for investigation of chemical constituents in the essential oil. Extraction of the essential oils produced yields ranging from 0.7 to 1.5 mL per 100 g dry tissue. An analysis of the oils by GC and GC/MS revealed 40 compounds, constituting 90.1-99.9 % of the essential oils. Chemical constituents varied with the site of sample origin, although the principal essential oil components from all populations, were α-pinene (17.5-37.1 %), 1,8-cineole (9.9-29.8 %), linalool (7.0-23.1 %), and α-terpineol (5.3-8.3 %). Limonene (tr, 22.7 %) was a major constituent in three populations. Characterized chemotypes included Chemotype I: α-pinene/1,8-cineole/linalool, Chemotype II: α-pinene/linalool, Chemotype III: α-pinene/1,8-cineole, and Chemotype IV: α-pinene/1,8-cineole/limonene. The main source of variability in chemical composition and oil yield appeared to be differences in environmental conditions and chemotypes as plant populations collected from close geographical areas could be classified in a cluster. [ABSTRACT FROM AUTHOR]