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The free-radical-scavenging property, antibacterial activity and brine shrimp toxicity of petroleum ether (PE), dichloromethane (DCM) and methanol (MeOH) extracts of Centaurea persica, a Turkish medicinal plant, were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtiter plate based assay, and the brine shrimp lethality assay, respectively. Additionally, the disc diffusion assay was also used to assess antibacterial activity. Only the MeOH extract of C. persica exhibited a significant free-radical-scavenging property in the DPPH assay, with an RC50 value of 0.025 mg/mL. However, in the TLC-based qualitative assay, petroleum ether and DCM extracts showed an extremely low level of free-radical-scavenging property. Among the solid-phase extraction fractions of the MeOH extract, the fractions eluted with 60% and 80% MeOH in water exhibited the highest level of free-radicalscavenging activity (RC50 = 0.010 and 0.015 mg/mL, respectively). While DCM extract showed reasonable antibacterial activity against five out of the nine test strains both in the disc diffusion assay and in the resazurin assay, the MeOH extract was highly active against both Escherichia coli and ampicillin-resistant E. coli strains. Among the solid-phase extraction fractions of the MeOH extract, fractions eluted with 80% MeOH in water and 100% MeOH displayed significant antibacterial potencies against both E. coli species. None of the extracts showed any significant toxicity towards brine shrimps (LD50 = >1.00 mg/mL).

Rumex obtusifolius L. (Polygonaceae), commonly known as 'broad-leaf dock', is one of the most common Irish wayside weeds, and it also occurs in silage fields, on river banks, in ditches and on waste grounds. The ethnobotanical uses of this species include its use as an antidote to nettle, depurative, astringent, laxative, and tonic, and in the treatment of sores, blisters, burns, cancer and tumors. The bioactivities of n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of the leaves of R. obtusifolius were assessed using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, the newly developed micro-titer-based antimicrobial assay incorporating resazurin as an indicator of cell growth, and the brine shrimp lethality assay. The most potent free radical scavenging activity was displayed by the MeOH extract with a RC50 value of 7.80 x 10-2 mg/mL. Among the fractions obtained from solid-phase extraction (SPE) of the MeOH extract, the 50% aqueous methanolic SPE fraction exhibited the highest levels of free radical scavenging property (RC50 = 1.05 x 10-2 mg/mL). While the n-hexane extract did not show any antibacterial activity at test concentrations, the DCM extract was active only against Escherichia coli. However, the MeOH extract as well as the 50% and 80% SPE fractions of the MeOH extract showed significant antibacterial property against all bacterial strains tested. None of the extracts or fractions exhibited any significant toxicity towards brine shrimps.

The free radical-scavenging property, antibacterial activity, and brine shrimp toxicity of n-hexane, dichloromethane (DCM), and methanol (MeOH) extracts of Centaurea polyclada, an endemic Turkish species, were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtiter plate-based assay, and the brine shrimp lethality assay, respectively. The DCM and MeOH extracts of C. polyclada exhibited free radical-scavenging ability with RC50 values 1.17 and 0.015 mg/mL, respectively. Among solid-phase extraction fractions of the MeOH extract, the fraction eluted with 60% MeOH in water demonstrated the highest level of free radical-scavenging activity (RC50 = 0.016 mg/mL). Only the DCM extract showed considerable antibacterial activity against all nine test strains except Escherichia coli, with MIC ranging from 1.25 to 2.50 mg/mL. This antibacterial activity pattern was also observed with solid-phase extraction fractions of the DCM extract with varied potencies. None of the extracts showed any significant toxicity towards brine shrimps (LD50 = >1.00 mg/mL).

Ferula orientalis (Apiaceae) is a well-known perennial herb growing wild in Iran used in traditional medicine. To perform phytochemical studies, dried ground roots of F. orientalis were sequentially Soxhlet-extracted using n-hexane, dichloromethane and methanol. A combination of vacuum liquid chromatography and preparative thin-layer chromatographic analyses were performed to isolate coumarin esters. The structures of the isolated compounds were elucidated by spectroscopic means, and in vitro free-radical-scavenging property was determined by the DPPH assay. Two new coumarin esters, 7-O-(4,8,12,16-tetrahydroxy-4,8,12,16-tetramethyl-heptadecanoyl)-coumarinand 7-O-(4-hydroxy-4,8,12-trimethyl-trideca-7,11-dienoyl)-coumarin, named ferulone A and ferulone B, respectively, were isolated from the n-hexane extract of the roots of F. orientalis. Both compounds showed a low level of free-radical-scavenging property with the RC50 values of 0.252 and 0.556 mg/mL for compounds 1 and 2, respectively, as opposed to that of the positive control (quercetin) 0.004 mg/mL. This is the first report on the purification of coumarin esters from the genus Ferula. [ABSTRACT FROM AUTHOR]

Reversed-phase HPLC analyses of the methanol extract of the leaves of Erica arborea afforded a novel phenylpropanoid glucoside, named ericarborin, together with five flavonoids, dihydromyricetin 3-O-α-L-rhamnopyranoside, quercetin 3-O-β-D-glucopyranoside, quercetin 3-O-α-L-rhamnopyranoside, apigenin 7-O-β-D-glucopyranoside and apigenin 7-O-β-D-(6-O-acetyl-glucopyranoside). While the structure of ericarborin was determined by extensive 1D and 2D NMR analyses, the structures of all known flavonoids were determined by direct comparison of their spectroscopic data with respective literature data. The antioxidant properties of these compounds were assessed by the DPPH assay. The chemotaxonomic significance of these phenolic compounds has been discussed. [ABSTRACT FROM AUTHOR]

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Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is an Iranian medicinal plant that has traditionally been used as an abortifacient and to treat constipation, oedema, bacterial infections, cancer and diabetes. As part of our on-going studies on Iranian medicinal plants, thorough phytochemical investigation was carried out on this plant. The reversed-phase preparative HPLC was employed to isolate compounds from the butanol fraction of the hydro-methanolic (70%) extract of the fruits of the locally grown C. colocynthis. Structures of the isolated compounds [1-5] were elucidated by spectroscopic means. The antioxidant property of the flavonoids 1-3 was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Three flavone glucosides, isosaponarin [1], isovitexin [2] and isoorientin 3′-O-methyl ether [3] and two cucurbitacin glucosides, 2-O-β-D-glucopyranosylcucurbitacin I [4) and 2-O-β-D-glucopyranosylcucurbitacin L [5] were isolated and identified. Flavonoids 1-3 showed significant antioxidant properties. Since reactive oxygen species are important contributors to tissue injury, inflammation, cancer and many other ailments, the antioxidant properties of 1-3 probably contribute, at least to some extent, to the pharmacological and traditional medicinal uses of the C. colosynthis. [ABSTRACT FROM AUTHOR]

The reversed-phase preparative HPLC analysis of the methanol extract of the rhizomes of Eremostachys glabra (Lamiaceae) led to the isolation of two furanolabdane diterpene glycosides, phlomisoside II, and β -D-glucopyranosyl-(1→2)- β -D-glucopyranosyl ester of phlomisoic acid (named eremostachiin), the latter being a novel natural product. The structure of the new compound has been elucidated unambiguously by HRMS and a series of 1D- and 2D-NMR spectroscopic techniques. The free radical scavenging activity of these compounds was assessed using the DPPH assay. [ABSTRACT FROM AUTHOR]

Polygonum barbatum (L.) Hara var. barbata (Polygonaceae), commonly known as 'bekhanjabaj', is a Bangladeshi perennial herb. A combination of the normal phase column chromatography and preparative thin layer chromatography on silica gel afforded sitosterone (1) from the petroleum ether fraction, and viscozulenic acid (2) and acetophenone (3) from the chloroform fraction of the methanol extract of the aerial parts of this plant. The free-radical-scavenging properties the isolated compounds 1-3 were evaluated by the 2,2-diphenyl-1- picryl-hydrazyl (DPPH) assay. [ABSTRACT FROM AUTHOR]

Hydrodistillation of the ground flowering tops of Leucanthemum vulgare (Asteraceae), collected from Heyran (Ardabil Province, Iran), afforded a greenish yellow oil (yield 0.15%, v/w), which was analyzed by the GC-MS and the GC-FID. The volatile oil comprised 47 compounds representing 90.3% of the oil. Caryophyllene oxide (21.2%), aromadendrene oxide (13.7%), cis-β-farnesene (6.5%), 1-octen-3-yl-acetate (5.6%) and trans-caryophyllene (4.9%) were the major compounds. The volatile oil composition of L. vulgare collected from Iran (present study) was significantly different from that collected from elsewhere, indicating two possible chemotypes. The volatile oil showed free-radical-scavenging, antifungal and allelopathic effects. [ABSTRACT FROM AUTHOR]

Chemical composition of the essential oil obtained from the aerial parts of Scrophularia amplexicaulis Benth. was analyzed, for the first time, by the gas chromatography/mass spectrometry (GC-MS) and gas chromatography/flame ionization detection (GC-FID). A total yield of 3 mg of essential oil per100 g of plant dry mass was obtained, and 27 compounds were identified, representing 97.7% of total oil. The essential oil were characterized by a high content of oxygenated monoterpenes and phenolic derivatives. The main constituents were eugenol (53.8%), eugenol acetate (24.5%), β-caryophyllene (5.7%), caryophyllene oxide (6.4%) and aromadendrene oxide II (2.1%). The antimicrobial activity of the essential oil was tested against Staphylococcus aureus using the well diffusion method, and the free-radical-scavenging activity was assessed by the 2,2-diphenyl-picryl-hydrazyl (DPPH) assay. [ABSTRACT FROM AUTHOR]

The composition of the essential oils obtained from the flowering aerial parts of two populations of Thymus pubescens, collected from Mishov-Dagh, was determined by the GC-MS analyses. A total of 18 compounds, representing about 95% of the total oils, were identified in both samples of the essential oils. The essential oils of these two populations showed the presence of high amounts of citronellol (42.0% and 42.6%), geranyl acetate (14.0 and 14.0%), geraniol (13.0 and 13.1%), citronellyl acetate (3.9 and 3.8%), L-linalool (7.8% and 7.9%), cis-nerodiol (5.9% and 5.5%) and citronellyl acetate (3.9% and 3.8%). However, in the published literature, carvacrol, thymol and p-cymene were reported to be the major compounds in T. pubescens. This significant difference in the composition of the essential oils was a clear evidence of chemical polymorphism with in the T. pubescens taxon, suggesting that these two populations of T. pubescens were in deed a new chemotype of this species, and the name Thymus pubescens Boiss. & Kotschy ex Celak chemotype Citronellol for this new chemotype has been proposed. The antibacterial and free-radical-scavenging properties of the essential oils of T. pubescens have also been evaluated. [ABSTRACT FROM AUTHOR]

Ribes biebersteinii Berl. (Grossulariaceae), commonly known as 'reddish-black berry', is an Iranian medicinal plant found mainly in the region of the Arasbaran forests in Iran. Reversed-phase preparative HPLC analyses of the methanol extract of the leaves of this plant afforded four flavonol glycosides, e.g. quercetin 3-Osophoroside (1), quercetin 3-O-sambubioside (2), kaempferol 3-O-sophoroside (3) and kaempferol 3,5-di-O-β- D-glucopyranoside (4). The free-radical-scavenging properties of the n-hexane, DCM and MeOH extracts, as well as the isolated compounds 1-4 were evaluated by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay. [ABSTRACT FROM AUTHOR]

The gas chromatography-mass spectrometry (GC-MS) analysis of the vacuum liquid chromatographic (VLC) fractions of the dichloromethane (DCM) extract of the bulbs of Ornithogalum cuspidatum, a native perennial of Iran, Iraq and Turkey, led to the identification of a number of steroidal compounds. The free radical scavenging activity of the DCM extract was assessed by the 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay, and found to be much weaker (RC50 = 0.5197 mg/mL) than that of the positive control Trolox® (RC50 = 3.07 x 10-3 mg/mL). [ABSTRACT FROM AUTHOR]

Abstract: The reversed-phase preparative HPLC analysis of the methanol (MeOH) extract of the seeds of Centaurea americana afforded a dibenzylbutyrolactone lignan, 3″-O-caffeoyl arctiin (named americanin), together with five known lignans, arctiin, arctigenin, matairesinol, matairesinoside and lappaol A, and two known phytoecdysteroids, 20-hydroxyecdysone and makisterone A. While the structures of the known compounds were determined by direct comparison of the spectral data with published data, the structure of americanin was elucidated by UV, MS and a combination of 1D and 2D NMR spectral analyses. The antioxidant properties and toxicity of the extracts and the isolated compounds were determined by the DPPH and the brine shrimp lethality assays, respectively. [Copyright &y& Elsevier]

Abstract: A combination of vacuum liquid chromatography (VLC) and preparative thin layer chromatography (PTLC) of the dichloromethane extract of the aerial parts of the Iranian plant Pimpinella aurea afforded two phenylpropanoids, erythro-1′-(4-methoxyphenyl)-propan-1′,2′-diol (1) and erythro-1′-[4-(sec-butyl)-phenyl]-propan-1′,2′-diol (2), the latter being a natural product. The structures of these compounds were determined by spectroscopic means. The antioxidant properties of these compounds were assessed by the DPPH assay. The GC–MS analysis of the essential oils of P. aurea provided a chemical profile that was significantly different from the previously published reports. [Copyright &y& Elsevier]