Unusual Secondary Metabolites of the Aerial Parts of Dionysia diapensifolia Bioss. (Primulaceae) and Their Anti-Inflammatory Activity.

The genus Dionysia, belonging to the Primulaceae family, encompasses more than 50 species worldwide with a center of diversity located in the arid Irano-Turanian mountains. In this study, a phytochemical investigation of the aerial parts of D. diapensifolia Bioss. led to the isolation of 24 phenolic compounds 1-7 and 9-25, and one sesquiterpenoid 8. Compound 1 was identified as new natural product, while isolation of 2 and 3, already known as synthetic products, from a natural source is reported for the first time in the present study. Isolation of compound 8 from a Dionysia species and indeed the whole Primulaceae family is reported for the first time too. Structure elucidation was performed by extensive spectroscopic analyses (1D-, 2D-NMR, and MS), and by comparison with reported literature data. Furthermore, DP4+ chemical shift probability calculations were performed to establish the relative configuration of compound 1. Additionally, subfractions obtained by liquid-liquid extraction of the methanolic extract of the plant, and subsequently the isolated new and selected known compounds 1-4, 6, 8-11 obtained from the diethyl ether subfraction were investigated for their inhibitory effect on NO release and iNOS and COX-2 expression in J774A.1 murine macrophages. The results showed a potential anti-inflammatory activity of the obtained subfractions, of which the diethyl ether subfraction was the most active one in inhibiting NO release and COX-2 expression (p < 0.001). Among the investigated isolated compounds, compound 4 significantly (p < 0.001) inhibited NO release and iNOS and COX-2 expression in a comparable manner like the used positive controls (L-NAME and indomethacin, respectively). Moreover, other isolated substances displayed moderate to high inhibitory activities, illustrating the potential anti-inflammatory activity of Dionysia diapensifolia.

Green synthesis of silver nanoparticles using Eucalyptus leucoxylon leaves extract and evaluating the antioxidant activities of extract.

This study was designed to examine the in vitro antioxidant activity of essential oil and methanol extracts of Eucalyptus leucoxylon. Furthermore, the polar fraction of the extract was used as a reducing agent for the green synthesis of silver nanoparticles (Ag NPs). Antioxidant activities of the samples were determined by using three different test systems, namely DPPH and ß-carotene/linoleic acid and reducing power. The structure and composition of the prepared Ag NPs were characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-vis spectroscopy. Synthesised Ag NPs were almost spherical in shape with an average diameter of about ∼ 50 nm and synthesised within 120 min reaction time at room temperature.

In vitro bioactivity of essential oils and methanol extracts of Salvia reuterana from Iran.

The chemical composition of the essential oils, antioxidant activity (DPPH and beta-carotene/linoleic acid assays) and total phenolic content (Foline-Ciocalteu) of the flowers and leaves of Salvia reuterana were determined. Essential oils extracted from the flowers and leaves by hydrodistillation were analyzed by GC and GC/MS. Forty-four constituents, representing 99.7-99.9% of the oils, were identified. The major components were germacrene D, benzoic acid hexyl ester, bicyclogermacrene, beta-gurjunene and ishwarene, constituting 33.7-31.9% of the oils. The highest radical-scavenging activity (DPPH test) was shown by the methanol extract of the flowers (IC50 = 77.6 microg/mL). In the beta-carotene/linoleic acid assay, the methanol extract of the leaves showed the highest inhibition (40.3%) which was only slightly lower than that shown by BHT (82.9%). The total phenolic contents of the methanol extracts of the flowers and leaves as gallic acid equivalents were 81.4 and 88.3 microg/mg, respectively. The plant also showed good antimicrobial activity against three strains of tested microorganisms.

Comparative study on the antioxidant activities of the different extracts and the composition of the oil extracted by n-hexane from Iranian Vitex pseudo-negundo.

Antioxidant activities of different extracts obtained from the aerial parts of Vitex pseudo-negundo from Kashan, central Iran, were evaluated for the first time in this study using ß-carotene/linoleic acid and scavenging of free-radical (DPPH) assays. Water extract showed the highest activity in both assays. GC-MS analysis of the oil extracted by n-hexane revealed 46 compounds with trans-ß-farnesene being the main component. Several new compounds, not reported in the previous literature, were identified in the essential oil of this chemo-type.

Composition of essential oil and biological activity of extracts of Viola odorata L. from central Iran.

Essential oil composition of the leaves of Viola odorata L. growing wild in Kashan, central Iran, was extracted by hydro distillation-solvent extraction method and analysed using GC-MS technique. The analysis revealed the presence of 25 identified compounds, representing 92.77% of the oil with butyl-2-ethylhexylphthalate (30.10%) and 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-2(4H)-benzofuranone (12.03%) being the two main components. Several components were identified for the first time in this chemotype of V. odorata. Antioxidant and antibacterial activities of the oil, methanol and chloroform extracts were also evaluated for the first time in this research work.

Chemical composition of essential oil and in vitro antioxidant activities of the essential oil and methanol extracts of Eucalyptus loxophleba.

This study was designed to examine the chemical composition of the essential oil and the antioxidant activity of the essential oil and methanol extracts of Eucalyptus loxophleba Benth. subsp. The chemical composition of the essential oil of the leaves of E. loxophleba was analysed by GC and GC/MS. The main constituents of the oil were found to be 1,8-cineole (39.4%), methyl amyl acetate (19.8%) and aromadendrene (10%). Antioxidant activities of the samples were determined by two different test systems namely DPPH and ß-carotene/linoleic acid. In the DPPH system, the highest radical-scavenging activity was shown by the polar subfraction of the methanol extract (15.2 ± 1.7 µg mL⁻¹). Also, in the second case, the inhibition capacity (%) of the polar subfraction (94.1 ± 1.3) was found to be stronger. In addition, the amounts of total phenol components in the polar subfraction (273.0 ± 2.6 µg mg⁻¹) and nonpolar subfraction (146.3 ± 2.5 µg mg⁻¹) were determined.

Comparative study of composition and biological activities of SDE prepared essential oils from flowers and fruits of two Hypericum species from central Iran.

Essential oil (EO) compositions of flowers and fruits of Hypericum perforatum L. and Hypericum scabrum L. growing wild in Kashan, central Iran, were determined by simultaneous steam distillation-solvent extraction method and analysed using GC-MS technique. Analysis revealed 28 identified compounds for H. perforatum, with two main components being α-pinene (25.36%) and α-amorphene (12.12%). Thirty-five compounds were identified in H. scabrum L. representing 98.60% of the oil with α-pinene (70.21%) and p-mentha-1,5-dien-8-ol (2.89%) as main components. Some new compounds were found in significant quantities which were not found in other chemotypes. The antioxidant activities of the EOs evaluated for the first time in this study using ß-carotene bleaching and DPPH assays seemed to be attributed directly to α-pinene contents in them. Antibacterial activities of both mentioned EOs were higher than that of their main constituent, α-pinene, against Staphylococcus aureus and Escherichia coli.

Essential oil composition and antioxidant and antimicrobial properties of the aerial parts of Salvia eremophila Boiss. from Iran.

The essential oil composition and in vitro antioxidant and antimicrobial activity of the essential oil and methanol extract of Salvia eremophila were evaluated in this research. GC and GC/MS analysis of the plant essential oil resulted in the identification of 28 compounds representing 99.24% of the oil. Borneol (21.83%), alpha-pinene (18.80%), bornyl acetate (18.68%) and camphene (6.54%) were detected as the major components consisting 65.85% of the oil. The plant essential oil and methanol extract were also subjected to screenings for the evaluation of their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid tests. While the plant essential oil showed only weak antioxidant activities, its methanol extract was considerably active in both DPPH (IC(50)=35.19 microg/ml) and beta-carotene-linoleic acid (inhibition percentage: 72.42%) tests. Appreciable total phenolic content (101.25 microg/mg) was also detected for the plant methanol extract as gallic acid equivalent in the Folin-Ciocalteu test. The plant was also screened for its antimicrobial activity and good to moderate inhibitions were recorded for its essential oil and methanol extract against most of the tested microorganisms.

Chemical composition and antioxidant activities of the essential oil and methanol extracts of Psammogeton canescens.

This study is outlined to probe the chemical composition of essential oil and in vitro antioxidant activity of the essential oil and methanol extracts of Psammogeton canescens. The chemical composition of the hydrodistilled essential oil of the aerial parts of P. canescens was analyzed by GC and GC/MS. The main constituents of the oil were found to be beta-bisabolene (33.35%), apiole (28.34%), alpha-pinene (11.86%) and dill apiole (8.17%). Antioxidant activities of the samples were determined by three various testing systems namely DPPH, beta-carotene/linoleic acid, and reducing power assay. In DPPH system, the highest radical-scavenging activity was seen by the polar subfraction of methanol extract (49.5+/-1.21mug/ml). Furthermore, in the second case the inhibition capacity (%) of the polar subfraction (92.40%+/-0.72) found to be the stronger one. However, in the reducing power assay, a reverse activity pattern more than in the first two systems was observed, and the essential oil was stronger radical reducer than was the methanol extract in all of the concentration tested. Our findings demonstrate that the essential oil and methanol extracts of P. canescens possess significant antioxidant activities and may be suggested as a new potential source of natural antioxidant.