Effect of gamma rays on the essential oil and biochemical characteristics of the Satureja mutica Fisch & C. A. Mey.

There are 16 species in the genus Satureja L. (Lamiaceae), of which 10 are native. This research aimed to investigate the effect of gamma rays and storage conditions and duration on the percentage and components of the essential oil and some biochemical characteristics of Satureja mutica Fisch & C.A. Mey at the Research Institute of Forests and Rangelands. Plants were collected at the full flowering stage and exposed to different doses of gamma rays (0, 2.5, 5, 7.5, and 10 kGy) at the Atomic Energy Organization, Iran. The samples were kept in a refrigerator (4 °C) and in the shade (25 ± 2 °C) for 0, 120, and 240 h. This experiment was performed in a completely randomized design. Essential oil extraction was done by water distillation for 2 h. The composition of their essential oil components was identified using GC and GC/MS. Some biochemical traits, including phenol content, antioxidant capacity, and carbohydrate content, were measured. The results indicated that irradiation on the percentage of essential oil showed a statistically significant difference. In addition, the interaction effect of irradiation × storage conditions, irradiation × duration of storage, on the percentage of essential oil was significant. According to a comparison of the means, 2.5 kGy irradiation produced the highest percentage of essential oil (0.4%); in contrast, a significant decrease was detected in components with 7.5 and 10 kGy irradiation. It was observed that the percentage of some essential oil compounds decreased with the gamma-ray intensity increase. 2.5 kGy of gamma rays and shade storage conditions for 240 h led to the highest content of p-cymene and carvacrol. Nevertheless, the highest thymol content was obtained under refrigeration conditions without irradiation. The maximum phenol content and antioxidant capacity were obtained when the plants were irradiated with 2.5 and 7.5 kGy gamma rays. However, the maximum carbohydrate rate was observed in non-irradiated plants. It was concluded that low-intensity gamma rays could improve the percentage of essential oil and main components like p-cymene and carvacrol in S. mutica Fisch & C.A. Mey.

Development of core-shell magnetic molecularly imprinted polymer-based electrochemical sensor for sensitive and selective detection of ezetimibe.

A sensitive electrochemical molecularly imprinted polymer (MIP) sensor was fabricated for detection of ezetimibe (Eze) as an effective cholesterol absorption inhibitor on the surface of a screen-printed carbon electrode based on a magnetic nanoparticle decorated with MIP (Fe3O4@MIP). Placing the magnetic nanoparticle inside the MIP increases the biocompatibility, surface-to-volume ratio, and sensitivity of the sensor. Methacrylic acid (MAA) was used as a monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, and Eze as a template. The fabricated Fe3O4@MIP was characterized using Fourier-transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Detection of Eze was achieved by differential pulse voltammetry. Using this sensor, Eze can be sensitively detected in the range of 1.0 nM-10 µM and detection limit of 0.7 nM. In addition, we have shown that the proposed sensor successfully detects different concentrations of Eze in human serum samples and thus proves its practical application.

Efficient synthesis of 9,10-dihydropyrano[2,3-h]chromene-2,8-dione derivatives in ionic liquid and the study of their antioxidant activity.

Ionic liquid N,N,N',N'-tetramethylguanidinium trifluoroacetate (TMGT) has been applied as a green and reusable catalyst for the one-pot synthesis of 10-aryl substituted-9,10-dihydropyrano[2,3-h]chromene-2,8-diones via reaction of various aromatic aldehydes, 5,7-dihydroxycoumarin derivatives and Meldrum's acid. The reactions were rapid, clean and the products were prepared in good yield. The ionic liquid was stable during the reaction process and reused without significant loss of its activity. The synthesised compounds were evaluated for their antioxidant activity by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay.

Label-free and sensitive aptasensor based on dendritic gold nanostructures on functionalized SBA-15 for determination of chloramphenicol.

A highly sensitive and low-cost electrochemical aptasensor was developed for the determination of chloramphenicol (CAP). The system was based on a CAP-binding aptamer, a molecular recognition element, and 1,4-diazabicyclo[2.2.2]octane (DABCO)-supported mesoporous silica SBA-15 on the surface of a screen-printed graphite electrode for formation of dendritic gold nanostructures and improving the performance and conductivity of the biosensor. Hemin has been applied as an electrochemical indicator which interacted with the guanine bases of the aptamer. In the absence of CAP, hemin binds to the aptamer and produces a weak differential pulse voltammetric (DPV) signal. The presence of CAP led to stabilization of the folded aptamer, which generated an amplified DPV signal. The peak current of hemin increased linearly with the concentration of CAP. Under optimal conditions, two linear ranges were obtained from 0.03 to 0.15 µM and 0.15 to 7.0 µM, respectively, and the detection limit was 4.0 nM. The prepared biosensor has good selectivity against other non-target drugs. Thus, the sensor could provide a promising platform for the fabrication of aptasensors. The feasibility of using this aptasensor was demonstrated by determination of CAP in a human blood serum sample.

Antioxidant and antibacterial activity of flavonoid-, polyphenol- and anthocyanin-rich extracts from Thymus kotschyanus boiss & hohen aerial parts.

The total phenolic and flavonoid contents, antioxidant and antibacterial properties of flavonoid- (water, ethyl acetate and hexane fractions), polyphenol- and anthocyanin-rich extracts of Thymus kotschyanus aerial parts were investigated. All the extracts showed significant amounts of phenolic and flavonoid compounds and exhibited strong antioxidant activity. Among the extracts, water fraction contained the highest phenolic and flavonoid contents (881.06 ± 16.52 mg GAE/g of extract and 74.60 ± 3.05 mg QE/g of extract, respectively). It also presented the highest DPPH(•) scavenging activity with an IC50 of 14.21 ± 0.53 µg mL(-1), and the highest reducing power at 400 µg mL(-1) by A700 = 2.46 ± 0.04. The extracts were found to exert moderate antibacterial activity against both Gram-negative and Gram-positive bacteria. These findings highlighted a scientific basis to the traditional usage of T. kotschyanus, also showed its potential as a rich source of natural antioxidant and antibacterial compounds.

Evaluation of the antioxidant and antibacterial properties of ethanol extracts from berries, leaves and stems of Hedera pastuchovii Woron. ex Grossh.

This study was designed to examine the total phenolic and flavonoid contents, radical scavenging and antibacterial activity of the ethanolic extracts from leaves, berries and stems of Hedera pastuchovii Woron. ex Grossh. The berry extract, which contained the highest phenolic and flavonoid compounds, showed an appreciable DPPH(·) scavenging ability in comparison with leaf and stem extracts. The various extracts exhibited moderate to good activity against both Gram-negative and Gram-positive bacteria, and the effectiveness of leaf extract was higher for all tested bacteria.

Biochemical activities of acetone extracts of Hyssopus angustifolius.

Antioxidant and antihemolytic activities of acetone extracts of Hyssopus angustifolius flowers, leaf and stems were investigated employing different in vitro and ex vivo assay systems. IC50, for 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical-scavenging activity were 239.4 +/- 8.4 microg/mL for flowers, 357.8 +/- 11.1 microg/mL for stems and 182.5 +/- 7.5 microg/mL for leaf. All extracts showed moderate nitric oxide scavenging activity. The leaf extract exhibited better hydrogen peroxide scavenging and Fe2+ chelating activity than the others (IC50 were 261.0 +/- 6.2 microg/mL for hydrogen peroxide and 534.0 +/- 9.9 microg/mL for Fe3+ chelating activity). The extracts exhibited good antioxidant activity in linoleic acid peroxidation system and weak reducing power ability. The leaf extract showed better antihemolytic activity than the flower and stem (IC50 = 65.7 +/- 1.8 microg/mL).

Biological activities of ethyl acetate extract of different parts of Hyssopus angustifolius.

CONTEXT: Hyssopus angustifolius M. Bieb. (Lamiaceae) is one of the most important medicinal plants in Iranian traditional medicine for the treatment of lung inflammation, laryngitis and cough relief. Much attention has been paid to this medicinal plant because of its traditional uses. OBJECTIVE: The present study examined the antioxidant and antihemolytic activities of ethyl acetate extract of stems, leaf and flowers of Hyssopus angustifolius. MATERIALS AND METHODS: Antioxidant activity of extracts was evaluated by employing six different models, i.e., DPPH, nitric oxide and hydrogen peroxide scavenging, metal chelating and reducing power activities and hemoglobin-induced linoleic acid system. Also, antihemolytic activity was evaluated against hydrogen peroxide-induced hemolysis. RESULTS: Flowers extract showed the better activity than leaf and stems extracts in DPPH radical scavenging activity (IC50 was 275.4 ± 7.6 µg mL⁻¹). Leaf, stems and flowers extracts showed good nitric oxide scavenging activity (IC50 were 376.6 ± 11.4 µg mL⁻¹ for flowers, 297.6 ± 9.6 µg mL⁻¹ µg mL⁻¹ for leaves and 837.8 ± 19.2 µg mL⁻¹ for stems). The leaf extract exhibited better hydrogen peroxide scavenging and Fe²âº chelating activity than stems and flowers extracts. In hemoglobin-induced linoleic acid system, all of the extracts exhibited very good activity. Also, extracts show weak reducing power activity. The ethyl acetate extract of leaf showed better antihemolytic activity than the flower and stems (IC50 was 94.0 ± 2.4 µg mL⁻¹). DISCUSSION AND CONCLUSION: These findings give a scientific basis to the traditional usage of Hyssopus angustifolius, also showing its potential as rich sources of natural antioxidant compounds.