Polar Subfraction Of Methanol Extract Research Articles

Changes in composition and antioxidant activities of essential oils in Phlomis anisodonta (Lamiaceae) at different stages of maturity

The composition of hydro-distilled essential oils of Phlomis anisodonta Boiss. subsp. occidentalis Jamzad in vegetative, flowering and post flowering stages were investigated using GC and GC-MS, leading to identification of 41, 26 and 23 compounds, respectively. In all three samples, sesquiterpenes were the main components. In vegetative stage the main components of the oil were germacrene-D (14.3%), bicyclogermacrene (12.4%) and α-pinene (6.8%); in flowering stage, germacrene-D (52.6%) and β-caryophyllene (15.9%); and in fruiting stage, germacrene-D (27.9%), bicyclogermacrene (17.6%), caryophyllene oxide (14.7%) and β-caryophyllene (11.3%). The samples were also subjected to screening for their possible antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid assays. In the first experiment, the free radical scavenging activity of polar subfraction of methanol extract in fruiting stage was superior to all other extracts (IC50= 41±0.4 μg/ml). When using linoleic acid system, oxidation of the linoleic acid was effectively inhibited by the non-polar subfraction of methanol extract in different stages. The results of this study show that the composition of essential oils varies considerably both in different parts of the plants and at different stages of development. When using the plants for medicinal purposes, it is important to be aware of the effective developmental phase, i.e. when the most effective components reach their peak volume, as well as the most useful parts. Phenology, Antioxidant activity, Volatile oils, Germacrene-D, Bicyclogermcrene

Chemical Composition and Antioxidant Activity of Essential Oil and Methanolic Extracts of Ferula microcolea (Boiss.) Boiss (Apiaceae)

The essential oils of Ferula microcolea, collected from west Iran were obtained by hydrodistillation during the flowering stage and analyzed by gas chromatography and gas chromatography/mass spectrometry. Under the optimum conditions of analysis, 22 constituents (mainly monoterpen compounds) were identified in Ferula microcolea, representing 93.6% of the oil. The main constituents were α-pinene (27.3%), β-pinene (16.4%), nonanal (8.7%), β-caryophyllene (8.5%), and thymol (6.7%). The samples were also subjected to screening for their possible antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl and β-carotene-linoleic acid assays. In the first case, the free radical-scavenging activity of polar sub-fraction of methanol extract showed to be superior as compared to other extracts (IC50 = 34.3 ± 0.3 μg/ml). Nonpolar sub-fraction of methanol extract exhibited stronger activity than the essential oil. In the case of the linoleic acid system, oxidation of the linoleic acid was effectively inhibited by the polar sub-fraction of methanol extract (86.5 ± 0.9%), while the oil and nonpolar sub-fraction of methanol extract were less effective (55.2 ± 0.4% and 81.5 ± 0.8%, respectively).

Chemical Composition, Antioxidant, and Antibacterial Activities of the Essential Oil and Methanol Extracts of Eucalyptus oleosa Leaves

This study was designed to examine the chemical composition of essential oil and in vitro antioxidant and antibacterial activity of the essential oil and methanol extracts of Eucalyptus oleosa F. Muell. The chemical composition of the hydrodistilled essential oil of the leaves of E. oleosa was analyzed by gas chromatography and gas chromatography/mass spectrometry. The main constituents of the oil were found to be 1,8-cineole (45.1%), α-pinene (14.52%), and α-terpineol (4.35%). The essential oil showed strong antibacterial activity against the test microorganisms studied, while polar subfraction of methanol extract had moderate antibacterial activity and the nonpolar subfraction of methanol extract did not show any antibacterial activity. In contrast, the extract showed much better activity than the essential oil in antioxidant activity assays employed, e.g., in DPPH systems, the highest radical-scavenging activity was shown by the polar subfraction (15.1 ± 0.7 μg/ml). In the second case, the inhibition capacity (%) of the nonpolar subfraction (98.2% ± 1.5) was found to be the stronger one. In addition, the amounts of total phenol components in the polar subfraction (186.3 ± 2.1 μg/mg) and the nonpolar subfraction (79.6 ± 1.4) were determined.

Chemical Composition, Antioxidant, and Antibacterial Activities of the Essential Oil and Methanol Extracts of Eucalyptus largiflorens F. Muell

This study was designed to examine the chemical composition of essential oil and in vitro antioxidant and antimicrobial activity of the essential oil and methanol extracts of Eucalyptus largiflorens F. Muell. The chemical composition of the hydrodistilled essential oil of the leaves of E. largiflorens was analyzed by gas chromatography and gas chromatography/mass spectrometry. The main constituents of the oil were found to be 1,8-cineole (23.1%), cryptone (15.1%), 4-allyloxyimino-2-carene (11.2%), and 4-terpineol (9.6%). The essential oil showed strong antibacterial activity against the studied microorganisms, except for P. aeruginosa, while polar subfraction of methanol extract had moderate antimicrobial activity and the nonpolar subfraction of methanol extract did not show any antimicrobial activity. In contrast, the extract showed better activity than the essential oil in antioxidant activity assays employed, e.g., in a 2,2-diphenyl-1-picryl-hydrazyl system. Also, the polar subfraction of methanol extract (15.1 ± 0.7 μg/ml) showed the highest radical-scavenging activity. In the second case, the inhibition capacity (%) of the nonpolar subfraction (92.7% ± 2.5) was found to be the stronger one. Finally, the total amounts of phenol constituents in the polar subfraction (142.6 ± 0.9 μg/mg), nonpolar subfraction (68.6 ± 0.4 μg/mg), and the oil (36.0 ± 0.6 μg/mg) were determined.

Determination of the chemical composition and in vitro antioxidant activities of essential oil and methanol extracts of Echinophora platyloba DC

This study was designed to examine the chemical composition and in vitro antioxidant activity of essential oil and methanol extracts of Echinophora platyloba from Iran. Gas chromatography (GC) and GC/MS (mass spectrometry; MS) analysis of the essential oil resulted in the identification of 29 compounds, which comprised 97.4% of the oil. The main constituents were found to be: (Z)-β-ocimene (26.7%), Δ-3-carene (16.2%) and limonene (6.6%). Antioxidant activities of the essential oil and the methanolic extracts from E. platyloba were evaluated using three different test systems, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, β-carotene–linoleic acid bleaching and reducing power assays. In the DPPH system, the highest radical-scavenging activity was shown by the polar sub-fraction of methanol extract (71.2 ± 1.11 µg mL−1). Also in the second case, the relative inhibition capacity (%) of the essential oil (68.0 ± 1.14%) was found to be the stronger one. In addition, the amounts of total phenol components in the polar sub-fractions of methanolic extract (67.5 ± 0.48 µg mg−1), nonpolar sub-fractions of methanol extract (35.3 ± 0.12) and the oil (83.3 ± 0.24 µg mg−1) were determined.

The in vitro antioxidative properties of the essential oils and methanol extracts of Satureja macrosiphonia Bornm

This study was designed to examine the in vitro antioxidant activities of the essential oil and methanol extracts of Satureja macrosiphonia in pre-flowering and flowering stages. GC and GC-MS analyses of the essential oils resulted in the identification of 35 and 24 compounds, representing the 95.1% and 92.6% of the oils, respectively. Major constituents of the oil of the pre-flowering stage were terpinene-4-ol (20.8%) and α-terpineol (14.7%), while in the oil of the flowering stage α-terpineol (26.7%) and borneol (16.6%) were found to be the main components. The samples were subjected to screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene–linoleic acid assay. In general, the polar subfraction of methanol extract in the flowering stage exhibited the greatest antioxidant activity in the DPPH test. In the β-carotene–linoleic acid test, the essential oil of the flowering stage had the highest antioxidant activities.

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 β-bisabolene (33.35%), apiole (28.34%), α-pinene (11.86%) and dill apiole (8.17%). Antioxidant activities of the samples were determined by three various testing systems namely DPPH, β-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 ± 1.21 μg/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.

Studies on the antioxidant activity of the essential oil and methanol extract of Marrubium globosum subsp. globosum (lamiaceae) by three different chemical assays

This study is designed to examine the chemical composition and in vitro antioxidant activity of the essential oil and sub-fractions of the methanol extract of Marrubium globosum subsp. globosum. The GC and GC–MS analysis of the essential oil were resulted in the determination of 84 components representing 88.2% of the oil. The major constituents of the oil were spathulenol (15.8%), β-caryophyllene (9.0%), caryophyllene oxide (7.9%), germacrene D (6.5%), and bicyclogermacrene (3.1%). Antioxidant activities of the samples were determined by three different test systems namely DPPH, β-carotene/linoleic acid and reducing power assay. In DPPH system, the weakest radical scavenging activity was exhibited by the essential oil (1203.38 ± 7.18 μg ml −1). Antioxidant activity of the polar sub-fraction of methanol extract was superior to the all samples tested with an EC 50 value of 157.26 ± 1.12 μg ml −1. In the second case, the inhibition capacity (%) of the polar sub-fraction of methanol extract (97.39% ± 0.84) was found the strongest one, which is almost equal to the inhibition capacity of positive control BHT (97.44% ± 0.74). In the case of reducing power assay, a similar activity pattern was observed as given in the first two systems. Polar sub-fraction was the strongest radical reducer when compared with the non-polar one, with an EC 50 value of 625.63 ± 1.02 μg ml −1. The amount of the total phenolics was highest in polar sub-fraction (25.60 ± 0.74 μg/mg). A positive correlation was observed between the antioxidant activity potential and total phenolic level of the extracts. On the other hand, total flavonoid content was found equal for the both sub-fractions.