Bioactivity and chemical characterisation of Lophostemon suaveolens – an endemic Australian Aboriginal traditional medicinal plant

Lophostemon suaveolens is a relatively unexplored endemic medicinal plant of Australia. Extracts of fresh leaves of L. suaveolens obtained from sequential extraction with n-hexane and dichloromethane exhibited antibacterial activity in the disc diffusion and MTT microdilution assays against Streptococcus pyogenes and methicillin sensitive and resistant strains of Staphylococcus aureus (minimum bactericidal concentration < 63 μg/mL). The dichloromethane extract and chromatographic fractions therein inhibited nitric oxide in RAW264.7 murine macrophages (IC₅₀ 3.7–11.6 μg/mL) and also PGE₂ in 3T3 murine fibroblasts (IC₅₀ 2.8–19.7 μg/mL). The crude n-hexane, dichloromethane and water extracts of the leaves and chromatographic fractions from the dichloromethane extract also showed modest antioxidant activity in the ORAC assay. GC–MS analysis of the n-hexane fraction showed the presence of the antibacterial compounds aromadendrene, spathulenol, β-caryophyllene, α-humulene and α-pinene and the anti-inflammatory compounds β-caryophyllene and spathulenol. Fractionation of the dichloromethane extract led to the isolation of eucalyptin and the known anti-inflammatory compound betulinic acid.     

Chemical composition of Helietta parvifolia and its in vitro anticholinesterase activity

The chemical composition of the essential oil and the n-hexane (Hex), Ethyl Acetate (EtOAc) and butanol (BuOH) extracts from the leaves of Helietta parvifolia were determined by detailed GC-MS analysis, spectroscopic and spectrometric data. Eighty-four compounds were identified, revealing a furoquinoline alkaloid-rich composition. The phytochemical analysis of the extracts allowed the isolation of eigth furoquinoline alkaloids. Retention indices in GC-MS for six of this alkaloids are reported for the first time. Furoquinoline alkaloids are acethylcholinesterase inhibitors. Thus, the essential oil and extracts were submitted to this in vitro assay. The EtOAc and BuOH extracts showed potent activity, with IC₅₀ of 9.7 and 12.9 μg mL^?1, respectively. Additionaly, a correlation of their chemical constituents, established by principal component analysis (PCA) demostrated a similar profile and a high content of alkaloids. It is for these reasons that we can assume that the alkaloid content in these extracts could be responsible for their anticholinesterase activity.     

A new ester coumarin from Ferula Persica wild,indigenous to Iran

Ferula persica wild (Apiaceae) is a perennial herb indigenous to Iran. It has been used in folk medicine for treatment of diabetes, lowering of blood pressure and for antispasmodic, carminative, laxative and expectorant effects in central Iran. Dried ground roots of F. persica (150 g) were extracted sequentially with n-hexane, dichloromethane and methanol (MeOH), 500 ml each, using a Soxhlet apparatus. The n-hexane extract of the roots (3 g) was subjected to vacuum liquid chromatography on silica gel, eluting with solvent mixtures of increasing polarity: 100% n-hexane–ethyl acetate (EtOAc), to yield a number of fractions, Fraction 4 (80% EtOAc in n-hexane) was further analysed by preparative TLC (mobile phase was 12% acetone in chloroform) to yield a coumarin ester (10.1 mg, R_f = 0.31, blue florescent). The structure of the isolated compound was elucidated by spectroscopic means. The compound is 7-O-(4,8,12 -trihydroxy-4,8,12-trimethyl-tridecanoyl)-coumarin, named, ferulone C as a new natural product.     

A new triterpene and protective effect of Periploca somaliensis Browicz fruits against CCl4-induced injury on human hepatoma cell line (Huh7)

The potential hepatoprotective effect of the methanolic extract of Periploca somaliensis Browicz fruits, its different fractions (n-hexane, chloroform and n-butanol) and the major isolated compound ursolic acid was evaluated using the human hepatoma cell line (Huh7) based on the changes in the activity of aspartate aminotransferase, alanine transaminase, glutathione and superoxide dismutase. Each sample was tested at three different concentrations (1000, 100 and 10 μg/mL). All tested samples exhibited a potent concentration-independent cytoprotective effect relative to silymarin as a reference standard. Chromatographic fractionation of the chloroform-soluble fraction of the methanol extract of P. somaliensis Browicz fruits afforded two known triterpenes, namely ursolic acid, and 11α,12α-epoxy-3β-hydroxy-olean-13β,28-olide, and a newly discovered one, namely 3β-hydroxy-urs-11-en-13β,28-olide. The structures of the isolated compounds were elucidated by the analysis of 1D and 2D NMR spectral data.     

A new flavan from the Drynaria bonii H. Christ rhizomes

In Vietnam, the medicinal plant Drynaria bonii H. Christ is used for the treatment of osteoporosis, bone fractures, and stimulate the growth of hair, treat tinnitus (Ho 2002; Loi 2004). In this article, experiments were designed to investigate the proliferation activity of ethanol, n-hexane, chloroform, ethyl acetate and methanol extracts from D. bonii rhizomes on MG-63 human osteoblast-like cells. The results showed that methanol and hexane extracts had the ability to proliferate MG-63 cells at the concentration varying from 0.1 to 0.01 μg/mL. In particular, at the concentration of 0.01 μg/mL, hexane and methanol extracts illustrated the highest proliferation ratio with 9.31% and 6.16%, respectively. By column chromatography, a new compound named drynaether A (1) and five known compounds uracil (2), 4′-hydroxy-7-methoxyflavan (3), kaempferol (4), indole-3-carboxylic acid (5) and protocatechuic acid (6) were isolated and identified from the methanol extract.     

Chemical constituents of Oldenlandia pinifolia and their antiproliferative activities

This study describes the chemical constituents of Oldenlandia pinifolia (Wall. Ex G. Don) Kuntze (synonym Hedyotis pinifolia Wall. Ex G. Don) and discusses their anti-proliferative activities. Thirteen compounds were isolated from the n-hexane, ethyl acetate and n-butanol extracts of whole plants O. pinifolia by chromatography method. Their structures were elucidated using MS and NMR analysis and compared with reported data. They are three anthraquinones, a carotenoid, two triterpenes, four iridoid glycosides and three flavonoid glycosides. Among them, 2-methyl-1,4,6-trihydroxy-anthraquinone is a new one, and three compounds were found for the first time in this genus. MTT assay resulted that the n-butanol extract and four isolated compounds inhibited the proliferation of chronic myelogenous leukaemia cells. The results from Hoechst 33343 staining and caspase 3-inducing exhibited that those four tested compounds induced apoptosis and activated caspase 3 (p < 0.05). One of them, isorhamnetin-3-O-β-rutinoside showed the most activity with IC₅₀ value of 394.68 ± 25.12 μM.     

Three new acyltyramines from Anisodus luridus Link et Otto (Solanaceae)

Three new acyltyramines, N-[2-(4-hydroxyphenyl)ethyl]hentriacontanamide (1), N-[2-(4-hydroxyphenyl)ethyl]nonacosanamide (2) and N-[2-(4-hydroxyphenyl)ethyl]heneicosanamide (3) have been isolated from n-hexane extract of leaves of Anisodus luridus (Solanaceae). Successive extraction of defatted leaves of A. luridus with methanol afforded a residue on removal of solvent under reduced pressure. Residue was partitioned by means of chloroform and n-butanol. Chromatographic resolution of n-BuOH extract afforded six known compounds, apigenin (4), luteolin (5), quercetin (6), quercetin 3-O-α-l-rhamnoside (7), kaempferol 3-O-α-rhamnoside (8) and quercetin 3-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (9). The structures of the isolated compounds were assigned with the help of spectroscopic techniques. This is the first report of isolation of these compounds from this plant.     

A Pretreatment Method for GC–MS Determination of Endocrine Disrupting Chemicals in Mollusk Tissues

Automatic soxhlet extraction followed by silica gel cartridge cleanup process was developed as a pretreatment method for GC–MS determination of seven endocrine disrupting chemicals in mollusk tissues. Operation parameters including extraction time, adsorption flow rate and elution flow rate were optimized as 140 min, 2 mL min^?1 and 2 mL min^?1, respectively. Thirty percent dichloromethane in n-hexane and 70% dichloromethane in n-hexane were used as elution solvents in turn. Recovery rates were 93.7, 91.7, 84.5, 83.3, 88.4, 81.2, and 79.7% for nonylphenols (NPs), bisphenol A (BPA), 17α-ethynylestradiol (EE2), estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (E2), and estriol (E3), respectively. Acceptable relative standard derivations ranged from 8.5 to 12.1%. Method detection limits ranged from 0.27 to 0.68 ng g^?1 dry weight (dw), and quantitative detection limits ranged from 0.62 to 1.26 ng g^?1 dw. The method was successfully applied to five mollusk species in Dapeng Bay of China to verify its practicability, and NPs, BPA, EE2, E1 and 17α-E2 were detected in the range from 1.6 to 131.5 ng g^?1 dw.     

Preparative separation of six terpenoids from Wedelia prostrata Hemsl. by two-step high-speed counter-current chromatography

Terpenoids are principal chemical compounds of Wedelia prostrata Hemsl. and have different biological activities, thus the study on separation and purification of terpenoids from W. prostrata Hemsl. is necessary. In this paper, high-speed counter-current chromatography (HSCCC) was successfully established for preparative isolation and purification of terpenoids from extracts of petroleum ether fraction which extracted from whole herbs of W. prostrata Hemsl. In the process, a total of 750?mg of sample was prepared for HSCCC isolation. Terpenoids were separated and purified with the two-phase solvent system n-hexane–ethyl acetate–methanol–water (9:1:9:1, 19:1:19:1, v/v/v/v). Therefore, 5α-hydroxy-2-oxo-p-menth-6(1)-ene (4.4?mg), 3α-angeloyloxy-ent-kaur-16-en-oic acid (5.6?mg), 3α-tigloyloxy-ent-kaur-16-en-oic acid (5.7?mg), 3α-phenylpropionoyloxy-ent-kaur-16-en-oic acid (7.3?mg), 3α-senecioyloxy-ent-kaur-16-en-oic acid (11.4?mg), and kaurenoic acid (12.3?mg) were obtained from W. prostrata Hemsl. and their purities reached standard determined by HPLC. Among them, 3α-phenylpropionoyloxy-ent-kaur-16-en-oic acid and 5α-hydroxy-2-oxo-p-menth-6(1)-ene were first isolated with high quantity as a useful chemical resource. The structures of these compounds were identified by ESI-MS, ¹H-NMR, and ¹³C-NMR. The present results demonstrated that high-speed counter-current chromatography was a fast and efficient technique for preparative separation of six terpenoids from W. prostrata Hemsl. which provided a useful reference to solve the problem of their sample availability for drug development.     

Anti-Escherichia coli activity of extracts from Schinus terebinthifolius fruits and leaves

Ethanol extracts obtained from Schinus terebinthifolius Raddi fruits and leaves were active against Escherichia coli with MIC of 78 μg mL^?1 for both extracts. Phytochemical analyses revealed a major presence of phenolic acids, tannins, fatty acids and acid triterpenes in the leaves and phenolic acids, fatty acids, acid triterpenes and biflavonoids in the fruits. Major compounds isolated from the plant, such as the acid triterpene schinol, the phenolic acid derivative ethyl gallate and the biflavonoids agathisflavone and tetrahydroamentoflavone, showed very little activity against E. coli. Bioautography of the ethanol extracts on silica gel plate showed inhibition zones for E. coli. They were removed from the plate and the compounds identified as a mixture of myristic, pentadecanoic, palmitic, heptadecanoic, stearic, nonadecanoic, eicosanoic, heneicosanoic and behenic fatty acids.     

Phytochemical profiles,antioxidant and anti-acetylcholinesterasic activities of the leaf extracts of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire in different solvents

In this work, the extracts obtained with different solvents from the leaves of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire were studied for their phytochemical profile and then for their antioxidant and acetylcholinesterase inhibitory activities. The phytochemical profiles of the extracts in n-hexane, dichloromethane, ethyl acetate, methanol, anthraquinone rich and water, showed the presence of different compounds belonging to several classes of natural products such as flavonoids, anthraquinones, saccharides and fatty acids. For what concerns the biological tests, the ethyl acetate, methanol and anthraquinone rich extracts showed the highest activities in both assays due to the high amount of compounds possessing those properties such as flavonoids and anthraquinones. By consequence, these specific extracts of the species may be considered to be potential sources of natural antioxidant and anti-acetylcholinesterasic compounds.     

Countercurrent chromatography separation of vitamin E isomers in a co-current mode

Vitamin E represents a group of lipophilic phenolic compounds, including α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol, and α-tocotrienol, β-tocotrienol, γ-tocotrienol, and δ-tocotrienol isomers. Different forms of vitamin E have been proven to exhibit varying biological activities. However, due to their structural similarities, the separation of vitamin E isomers is a challenging task. Therefore, it is crucial to establish an efficient method for isolating individual isomers. In this study, co-current countercurrent chromatography was employed to isolate vitamin E isomers from commercial capsules using a n-heptane-methanol-water (10:9.5:0.5, v/v) solvent system. The partition coefficients of the main constituents in the capsules ranged from 0.94 to 6.23, requiring over 450 min for a complete separation. To improve separation efficiency, a co-current elution mode was implemented and the flow rates of the two liquid phases as well as sample amount were examined. The results suggested that increasing the flow rate of the stationary phase and sample size could result in more effective separation, shorter separation time, and higher yield. It proved that co-current countercurrent chromatography was an effective method for the separation of vitamin E isomers.     

Anthemis cotula L. from Jordan: Essential oil composition,LC-ESI-MS/MS profiling of phenolic acids - flavonoids and in vitro antioxidant activity

Essential oils of the leaves and flowers of Anthemis cotula L. (family Asteraceae) grown in Jordan were extracted by hydro-distillation and then analyzed by GC–MS. Sesquiterpenes hydrocarbons (SH) were the dominant components in the oils extracted from leaves and flowers of A. cotula. γ-Muurolene and aromadendrene, were the major compounds that were obtained from the flowers oil, while γ-muurolene and trans-cadinene ether were detected as major ingredients in the leaves extract. LC-MS analysis was carried out to identify the significant compounds from each extract. Additionally, butanol (B), aqueous methanol (M) and water (W) extracts prepared from the flowers and the leaves of A. cotula were analysed by LC-MS/MS. Apigenin and chlorogenic acid were the main constituents detected in the flowers’ alcoholic extracts and leaves’ aqueous extract. Moreover, the essential oils and all prepared extracts were assayed for their total antioxidant activity using the DPPH, ABTS, and ferrous ion chelating effect (FIC) assay methods. All investigated oils and extracts showed interesting activity as compared to the positive controls employed (α-tocopherol and ascorbic acid).     

Anti-angiogenic activity of Entada africana root

Entada africana roots are used in African traditional medicine for various diseases including inflammation. This application may be mediated through anti-angiogenic effects. Thus, in this study the anti-angiogenic activity of E. africana root extracts (n-hexane, chloroform, chloroform/methanol and methanol) was preliminarily evaluated by the quantitative determination of endogenous alkaline phosphatase in zebrafish embryos. A bioactivity-guided fractionation of chloroform/methanol extract yielded apigenin and robinetin as the main constituents from the most active fractions. In addition, a marked reduction on capillary formation was evidenced in chick chorioallantoic membrane after treatment with the active fractions or isolated compounds. Results obtained in this study suggest that the anti-angiogenic effects of E. africana root may account for its use in inflammatory diseases and other related pathological conditions.     

Comparative study on the antioxidant activities of extracts of Coreopsis tinctoria flowering tops from Kunlun Mountains,Xinjiang, north-western China

Coreopsis tinctoria flowering tops (CTFs) from the Kunlun Mountains in Xinjing (north-western China) have been used for tea production for about a century. This study aims to assess the antioxidant activities and total phenolic, flavonoid and proanthocyanidin contents of various solvent extracts of CTF. CTF was extracted using n-hexane, chloroform, ethyl acetate, n-butanol, 75% aqueous ethanol (AEE) and water. The antioxidant activities of the CTF extracts were investigated through DPPH, ABTS, ^*OH, ^*O₂^? , total antioxidant capacity and reducing power assays. The results showed that n-butanol extract showed the highest contents of total phenols and flavonoids, with DPPH, ABTS and ^*OH radical-scavenging activities with IC₅₀ values of 134, 90.72 and 13.8 μg mL^? 1, respectively. The AEE demonstrated the strongest DPPH and ABTS radical-scavenging activities, with IC₅₀ values of 103 and 75.16 μg mL^? 1, respectively. Given its high antioxidant effect, CTF is a good source of natural antioxidants or functional food materials.     

Optimization and Validation of RP-LC/UV–VIS Detection Method for Simultaneous Determination of Fat-Soluble Anti-Oxidant Vitamins, all-trans-Retinol and α-Tocopherol in Human Serum: Effect of Experimental Parameters

A versatile isocratic reversed-phase liquid chromatographic/ultraviolet–visible detection method for simultaneous determination of all-trans-retinol and α-tocopherol in human serum was developed and validated after optimization of various chromatographic conditions and other experimental parameters. Analytes were separated on a Kromasil 100 RP₁₈ (150 × 4.6 mm, 5 μm) analytical column protected by a Perkin Elmer RP₁₈ (30 × 4.6 mm, 10 μm) guard cartridge. The mobile phase, methanol–water (96:04 v/v) was pumped at a flow rate of 2.2 mL min^?1 and the column eluents were monitored at the wavelength of 292 nm using retinyl acetate (1.0 μg mL^?1) as the internal standard for both analytes. Sample preparation was based on protein precipitation and stabilization with 2,6-bis(1,1-dimethylethyl)-4-methylphenol/ethanol and a two step extraction process using n-hexane followed by dichloromethane as extraction solvents. Sample size was kept 20 μL and separation of analytes was achieved in less than 7 min. The present method demonstrated acceptable values for specificity/selectivity, linearity within the expected concentration range, recovery, precision, sensitivity, stability of solutions, robustness, and system suitability specifications and tests. The method was used for monitoring all-trans-retinol and α-tocopherol concentrations in human serum samples and could also be applied to other sample matrices such as brain slices and cosmetic products if attention is paid to the extraction procedure.     

Transformations of n-Hexane and Cyclohexane by Barrier Discharge Processing in Inert Gases

The conversion of n-hexane and cyclohexane by barrier discharge treatment in He, Ar, Kr, or Xe was studied. The action of a barrier discharge on n-hexane vapor primarily results in the formation of branched-chain hydrocarbons (93.48 wt %). Bicyclohexyl is the main reaction product of cyclohexane; alkyl and alkenyl substituted cyclohexanes (48.12 wt %) are also formed. Using n-hexane as an example, it was demonstrated that the energy consumption increased from 1.30 to 2.17 keV per hydrocarbon molecule converted in the following order of inert gases: He, Ar, Kr, and Xe.     

Ferulone A and ferulone B: two new coumarin esters from Ferula orientalis L. roots

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.     

Inhibition of Pro-inflammatory Secreted Phospholipase A2 by Extracts from <Emphasis Type="Italic">Cynara cardunculus L</Emphasis>.

The aim of the present work was to evaluate the anti-inflammatory properties of Cynara cardunculus L. (Asteraceae) during its growth using various solvents such as n-hexane, dichloromethane, acetone, and methanol for air-dried leaves and stems. The anti-inflammatory activities of crude extracts were evaluated by measuring the inhibition potency of mammalian non-pancreatic phospholipases A2 (hG-IIA). The methanol and acetone extracts of leaves harvested in February exhibit potent inhibition of hG-IIA (IC₅₀ = 50 and 70 μg/ml, respectively). However, the acetone extract of stems harvested in December inhibits the hG-IIA with a lower IC₅₀ around 130 μg/ml. Fractionation on silica gel and hydrophobic gel of the methanol extract of leaves harvested in February increases the inhibitory effect, and the IC₅₀ reached 10 μg/ml.