Analysis of the essential oil ofThymus eriocalyx from Iran

Chemical Profiles and Insecticidal Potential of Essential Oils Isolated from Four Thymus Species against Rhyzopertha dominica (F.)

Although chemical pesticides have been efficiently used to manage insect pest, their overuse has led to environmental contamination and threats to human health, enticing researchers to introduce eco-friendly and effective agents. In this study, the insecticidal effectiveness of essential oils isolated from Thymus species, including T. eriocalyx, T. kotschyanus, T. fallax, and T. vulgaris, was evaluated against the adults of Rhyzopertha dominica. The terpenes p-cymene, 1,8-cineole, linalool, α-terpineol, and carvacrol were the prominent compounds in the hydrodistilled essential oils. All essential oils produced significant fumigant at 24, 48, and 72-exposure times. The energy reserves protein by all essential oils, glycogen by T. kotschyanus and T. vulgaris, and lipid by T. fallax and T. vulgaris were significantly decreased compared to control. All essential oils except T. vulgaris affected the amylolytic and proteolytic activity of the pest. The pest increased the α- and β-esterase enzyme activity in response to the essential oils. Nutritional indices of adults were also affected by essential oils, in which feeding deterrence index was calculated from 20.41% to 61.11%. Accordingly, based on lethal and extensive sub-lethal insecticidal activities, T. eriocalyx, T. kotschyanus, T. fallax, and T. vulgaris essential oils can be considered as efficient agents for R. dominica management.

Essential oils composition and antioxidant properties of three thymus species

The essential oils of three wild-growing Thymus species, collected from west of Iran during the flowering stage, were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Under the optimum extraction and analysis conditions, 44, 38, and 38 constituents (mainly monoterpenes compounds) were identified in T. kotschyanus Boiss. and Hohen, T. eriocalyx (Ronniger) Jalas, and T. daenensis subsp lancifolius (Celak) Jalas which represented 89.9%, 99.7%, and 95.8% of the oils, respectively. The main constituents were thymol (16.4–42.6%), carvacrol (7.6–52.3%), and γ-terpinene (3–11.4%). Antioxidant activity was employed by two complementary test systems, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging and β-carotene/linoleic acid systems. Antioxidant activity of polar subfraction of T. daenensis subsp lancifolius (Celak) Jalas was found to be higher than those of the others in DPPH assay, while nonpolar subfraction of T. eriocalyx (Ronniger) Jalas has most antioxidant activity in β-carotene/linoleic acid test (19.1 ± 0.1 μg/mL and 96.1 ± 0.8% inhibition rate, resp.).

Determination and discrimination of intraspecific diversity of Astragalus gossypinus by eco-phytosociological method from west of Iran

Astragalus gossypinus Fischer with wide distribution in Iran belongs to the genus Astragalus (Fabaceae). According to existing references and information, individuals of this species are present in many stations with different ecological conditions. This study carried out for determination and discrimination of intraspecific diversity of Astragalus gossypinus by Eco-phytosociological method from west of Iran. In this method, the principle of data collecting and analyzing based on floristical composition (as floristical markers) of each Endogenous milieu (as the unit of study in Eco-phytosociological method). In this order, application of Endogenous milieu (special station) for data collecting and then their analyzing permit us only determine existence of inter and intraspecific diversity. Then for determinating kind and level of intraspecific diversity (Ecophene, Chemotype, Cytotype, Ecotype ...), can use other studies such as: morphological, anatomical, phytochemical, cytological and etc. In this survey, 29 special stations were studied and 195 species distinguished as companions for Astragalus gossypinus. Then floristic-ecologic data collected from each 29 special stations and analyzed by Anaphyto software (F.C.A, A.H.C, B.O, Marquag methods). Comparison of obtained results on multiple coordinate axes from F.C.A method with results from B.O, Marquag and A.H.C methods led to determination of 7 main groups of Endogenous milieus (special station). Flavonoid analyses were used for determinating kind and level of intraspecific diversity in 7 discriminated groups. Leaves flavonoid components of all collected individuals of Astragalus gossypinus were investigated by TLC method. Obtained data from flavonoid survey analyzed by SPSS and MVSP package with WARD and UPGMA methods. Finally, the results of flavonoid studies confirmed the same 7 groups that identified by floristical composition study and showed intraspecific diversity in chemotype level. So according to these results, we can introduce 7 chemotypes for Astragalus gossypinus from west of Iran. These chemotypes exist in different stations with various ecological conditions.