Abstract: Two solar drying methods (direct cabinet solar dryer and indirect cabinet solar dryer) were tested under tropical conditions for drying aerial parts of sacha culantro (Eryngium foetidum L.) in Pucallpa City (Peruvian Amazon). The drying behavior was monitored during all experimental runs. Dried samples and fresh leaves were hydrodistilled and isolated oils were analyzed using gas chromatography with flame ionization detector and gas chromatography-mass spectrometry. (E)-2-dodecenal was determined as the main constituent of the sacha culantro essential oil, averaging 61.8-62.2%, followed by n-dodecanal (10.9-15.5%), (E)-2-tetradecenal (6.7-7.6%) and 1-tetradecene (3.6-5.7%). When comparing both solar drying methods, the indirect method was found as more suitable for drying E. foetidum since the dried product resembled the fresh herb more closely in its chemicalcomposition and had better appearance. However, a better drying efficiency of 10.3% was achieved when drying in the direct solar dryer compared with 5.8% for the indirect solar dryer.
Abstract: Seed extracts from six species of the genus Nigella (Family Ranunculaceae)-Nigella arvensis, Nigella damascena, Nigella hispanica, Nigella nigellastrum, Nigella orientalis, and Nigella sativa-obtained by successive extraction with n-hexane, chloroform, and methanol, were tested for their antimicrobial activity against 10 strains of pathogenic bacteria and yeast using the microdilution method as well as for anti-inflammatory properties by in vitro cyclooxygenase (COX)-1 and COX-2 assay. Chemical characterization of active extracts was carried out including free and fixed fatty acid analysis. Comparison of antimicrobial activity showed that N. arvensis chloroform extract was the most potent among all species tested, inhibiting Gram-positive bacterial and yeast strains with minimum inhibitory concentration (MIC) values ranging from 0.25 to 1 mg/mL. With the exception of selective inhibitory action of n-hexane extract of N. orientalis on growth of Bacteroides fragilis (MIC = 0.5 mg/mL), we observed no antimicrobial activity for other Nigella species. Anti-inflammatory screening revealed that N. sativa, N. orientalis, N. hispanica, N. arvensis n-hexane, and N. hispanica chloroform extracts had strong inhibitory activity (more than 80%) on COX-1 and N. orientalis, N. arvensis, and N. hispanica n-hexane extracts were most effective against COX-2, when the concentration of extracts was 100 microg/mL in both COX assays. In conclusion, N. arvensis, N. orientalis, and N. hispanica seeds, for the first time examined for antimicrobial and anti-inflammatory effects, revealed their significant activity in one or both assays.
Abstract: The aim of this study was to identify antimicrobial properties of essential oils in vapour phase. In vitro antibacterial activity against five foodborne bacteria (Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus) was evaluated by disc volatilization method. The results were expressed as minimum inhibitory concentrations (MIC) in mu l/cm(3) of air. Thirteen of the 27 essential oils were active at least against one bacterial strain in the range of tested concentrations (0.0083-0.53 mu l/cm(3)). The best results were shown by Armoracia rusticana (MIC 0.0083 mu l/cm(3)) against all of the strains, followed by Allium sativum > Origanum vulgare > Thymus vulgaris > Satureja montana. Thymus pulegioides > Thymus serpyllum > Origanum majorana > Caryopteris x clandonensis, Hyssopus officinalis, Mentha villosa, Nepeta x faassenii, Ocimum basilicum var. grant verte. In conclusion, certain essential oils are highly effective in vapour phase and could be used in control of foodborne bacterial pathogens. (C) 2008 Elsevier Ltd. All rights reserved.
Abstract: Seed extracts from six species of the genus Nigella (Family Ranunculaceae)-Nigella arvensis, Nigella damascena, Nigella hispanica, Nigella nigellastrum, Nigella orientalis, and Nigella sativa-obtained by successive extraction with n-hexane, chloroform, and methanol, were tested for their antimicrobial activity against 10 strains of pathogenic bacteria and yeast using the microdilution method as well as for anti-inflammatory properties by in vitro cyclooxygenase (COX)-1 and COX-2 assay. Chemical characterization of active extracts was carried out including free and fixed fatty acid analysis. Comparison of antimicrobial activity showed that N. arvensis chloroform extract was the most potent among all species tested, inhibiting Gram-positive bacterial and yeast strains with minimum inhibitory concentration (MIC) values ranging from 0.25 to 1 mg/mL. With the exception of selective inhibitory action of n-hexane extract of N. orientalis on growth of Bacteroides fragilis (MIC = 0.5 mg/mL), we observed no antimicrobial activity for other Nigella species. Anti-inflammatory screening revealed that N. sativa, N. orientalis, N. hispanica, N. arvensis n-hexane, and N. hispanica chloroform extracts had strong inhibitory activity (more than 80%) on COX-1 and N. orientalis, N. arvensis, and N. hispanica n-hexane extracts were most effective against COX-2, when the concentration of extracts was 100 mu g/mL in both COX assays. In conclusion, N. arvensis, N. orientalis, and N. hispanica seeds, for the first time examined for antimicrobial and anti-inflammatory effects, revealed their significant activity in one or both assays.
Abstract: A detailed analysis of Rhaponticum carthamoides (Willd.) Iljin root essential oil was carried out by GC, GC-MS and GC-FTIR techniques. In total, 30 components were identified, accounting for 98.0% of total volatiles. A norsesquiterpene 13-norcypera-1(5),11(12)-diene (22.6%), followed by aplotaxene (21.2%) and cyperene (17.9%), were isolated and their structures confirmed by 1D and 2D-NMR spectra (COSY, ROESY, HSQC, HMBC and INADEQUATE). Selinene type sesquiterpenes and aliphatic hydrocarbons were among minor constituents of the essential oil. The oil exhibited antimicrobial activity against 5 of 9 strains of bacteria and yeast, when tested using broth micro-dilution method. Minimum inhibitory concentrations ranged between 32 and 256 microg/ml.
Abstract: The antimicrobial activity of the dichloromethane extract from aerial parts of Leuzea carthamoides DC. was tested in vitro against 19 Staphylococcus aureus strains (ATCC 25923, CNCTC Mau 43/60, clinical isolates). The extract was fractionated by column chromatography on silica gel into six fractions (petroleum ether, toluene, dichloromethane, ethyl acetate, methanol and water). The minimum inhibitory concentrations (MICs) of the fractions ranged from 64 to 1024 mu g/mL. An ethyl acetate fraction (EA 1) with the widest range of activity inhibited all of the strains with MIC in the range 128-512 mu g/mL. This fraction exhibited potent activity against strains which showed associated resistance to oxacillin, ciprofloxacin and erythromycin.
Abstract: Eight C-6-geranylflavonoids ( 1- 8) were isolated from an ethanol extract of Paulownia tomentosa fruits. Tomentodiplacone ( 1), 3'- O-methyl-5'-hydroxydiplacone ( 2), 3'- O-methyl-5'- O-methyldiplacone ( 3), and tomentodiplacone B ( 4) were obtained as new compounds, and 3'- O-methyldiplacol ( 5) was isolated for the first time from a natural source. The structures of these new compounds were determined by using mass spectrometry (including HRMS) and 1D and 2D NMR spectroscopy, and the absolute configurations of the compounds were determined by circular dichroism. The antibacterial activities of 1- 8 against seven bacteria and yeast were evaluated.
Abstract: In vitro antimicrobial activity of 32 extracts (ethanol, hexane, chloroform, and methanol) from eight different Libyan medicinal plants, namely Artemisia herba-alba Asso (Compositae), Globularia alypum L. (Globulariaceae), Helichrysum stoechas, DC. (Compositae), Peganum harmala L. (Zygophyllaceae), Polygonum equisetiforme Sibth. & Sm. (Polygonaceae), Pulicaria crispa (Forssk.) Oliv. (Compositae), Rosmarinus officinalis L. (Labiatae), and Thymus capitatus Hoffmanns & Link. (Labiatae), was determined against seven bacteria and one yeast strain using the broth microdilution method. The results show that all plants tested possessed antimicrobial activity against at least one of the examined strains at a concentration <= 8 mg/ml. The extracts from H. stoechas, P. equisetiforme, P. crispa, R. officinalis, and T. capitatus exhibited strongest activity against Gram-positive bacteria with minimum inhibitory concentrations (MICs) ranging from 0.5 to 8mg/ml. Only a few extracts showed inhibitory activity against Gram-negative strains in this test, whereas those of the H. stoechas and P. harmala were among the strongest ones (MICs range 4-8mg/ml). High anticandidal activity was observed for P. harmala, P. crispa, and T. capitatus, with MICs ranging from 0.25 to 1 mg/ml.
Abstract: The aim of this study was to evaluate the antimicrobial activity of six barks traditionally used in CallerÃa District (Ucayali Department, Peru) for treating conditions likely to be associated with microorganisms. Ethanol extracts of stem barks of Abuta grandifolia (Menispermaceae), Dipteryx micrantha (Leguminosae), Cordia alliodora (Boraginaceae), Naucleopsis glabra (Moraceae), Pterocarpus rohrii (Leguminosae), and root bark of Maytenus macrocarpa (Celastraceae) were tested against nine bacteria and one yeast using the broth microdilution method. All plants possessed significant antimicrobial effect, however, the extract of Naucleopsis glabra exhibited the strongest activity against Gram-positive bacteria (MICs ranging from 62.5 to 125 microg/ml), while the broadest spectrum of action was shown by the extract of Maytenus macrocarpa, which inhibited all the strains tested with MICs ranging from 125 to 250 microg/ml.
Abstract: Nine ethanol extracts of Brunfelsia grandiflora (Solanaceae), Caesalpinia spinosa (Caesalpiniaceae), Dracontium loretense (Araceae), Equisetum giganteum (Equisetaceae), Maytenus macrocarpa (Celastraceae), Phyllanthus amarus (Euphorbiaceae), Piper aduncum (Piperaceae), Terminalia catappa (Combretaceae), and Uncaria tomentosa (Rubiaceae), medicinal plants traditionally used in Calleria District for treating conditions likely to be associated with microorganisms, were screened for antimicrobial activity against nine bacterial strains using the broth microdilution method. Among the plants tested, Phyllanthus amarus and Terminalia catappa showed the most promising antibacterial properties, inhibiting all of the strains tested with minimum inhibitory concentrations (MICs) ranging from 0.25 to 16 mg/ml. The extract from aerial part of Piper aduncum was significantly more active against Gram-positive (MICs ranging from 1 to 2 mg/ml) than against Gram-negative bacteria (MICs > 16 mg/ml).
