Composition, antioxidant and antimicrobial activities of methanol extracts of some Acinos Miller species.

GC and GC/MS analyses of the methanol extracts obtained from the aerial parts of six Acinos Miller species from Serbia and Montenegro were performed. Seventy-four constituents, accounting for 84.9-99.0% of the total composition of the extracts, were identified. The common feature of the A. suaveolens, A. majoranifolius and A. alpinus methanol extracts was the high content of monoterpenes, while the common feature of the A. graveolens, A. arvensis and A. hungaricus methanol extracts was the prevalence of sesquiterpenes. The total flavonoids, polyphenols and tannins content, as well as antioxidant activity (FRAP and DPPH assay) of the methanolic extracts were investigated. The highest antioxidant activity was observed in the extract of A. alpinus which had high levels of all polyphenol classes examined. A disk diffusion method was used for the evaluation of the antimicrobial activities of the extracts against a panel of microorganisms (bacteria: Bacillus subtilis, Clostridium pyogenes, Enterococcus sp., Micrococcus flavus, Sarcina lutea, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella enteritidis and Escherichia coli; fungi: Aspergillus niger, Candida albicans and Saccharomyces cerevisiae). The preliminary bioassay results indicated that the methanol extract of A. alpinus could be a possible source of antioxidant and antimicrobial compounds.

Chemical composition and antioxidant and antimicrobial activities of essential oil of Allium sphaerocephalon L. subsp. sphaerocephalon (Liliaceae) inflorescences.

BACKGROUND: Allium sphaerocephalon is a wild-growing plant commonly used as an onion substitute. In this study the essential oil obtained from A. sphaerocephalon subsp. sphaerocephalon inflorescences was analysed by gas chromatography and gas chromatography/mass spectrometry and also evaluated for in vitro antioxidant and antimicrobial activities. The obtained results are reported for the first time and discussed with respect to the sulfur compounds detected in the essential oil. RESULTS: Ninty-one compounds were identified, representing 91.6% (w/w) of the total oil. Major constituents of the analysed sample were shyobunol (15.3%), ß-caryophyllene (8.1%), α-cadinol (7.8%), 3,5-diethyl-1,2,4-trithiolane (isomer II, 5.9%) and δ-cadinene (5.2%). The diluted oil had an antioxidant capacity of 160 000 ± 111 micromol α-tocopherol acetate equivalents g(-1). Its antimicrobial activity was evaluated against five bacterial and two fungal strains using the broth microdilution assay. Among the micro-organisms tested, the most susceptible strains were Pseudomonas aeruginosa (minimal inhibitory/bactericidal concentration = 0.08/2.5 mg mL(-1)) and Aspergillus niger (minimal inhibitory/fungicidal concentration = 0.31/0.63 mg mL(-1)). CONCLUSION: The results showed that the examined species had strong antioxidant and antimicrobial properties and are in accordance with the popular use of plants belonging to the genus Allium in traditional medicine, emphasising the necessity of further detailed study of the active principles in Allium species.

Complete assignment of the 1H and 13C NMR spectra of antimicrobial 4-arylamino- 3-nitrocoumarin derivatives.

Herein, we describe the synthesis and complete assignment of the (1)H and (13)C NMR chemical shifts of a series of antimicrobial 4-arylamino-3-nitrocoumarin derivatives based on a combination of (1)H and (13)C NMR, (1)H-(1)H-COSY, NOESY, HSQC and HMBC experiments. Conformational effects upon the chemical shifts of the coumarin moiety arising from the anisotropy of the aryl side group are briefly discussed. This study provides the first complete and fully assigned NMR data for this important group of antimicrobial compounds and bridges the gap existing in the literature with regard to NMR structural data for 4-arylamino-3-nitrocoumarins.

Comparative study of the leaf volatiles of Arctostaphylos uva-ursi (L.) Spreng. and Vaccinium vitis-idaea L. (Ericaceae).

The first GC and GC/MS analyses of the essential oils hydrodistilled from dry leaves of Arctostaphylos uva-ursi and Vaccinium vitis-idaea enabled the identification of 338 components in total (90.4 and 91.7% of the total GC peak areas, respectively). Terpenoids, fatty acids, fatty acid- and carotenoid derived compounds were predominant in the two samples. Both oils were characterized by high relative percentages of α-terpineol and linalool (4.7-17.0%). Compositional data on the volatiles of the presently analyzed and some other Ericaceae taxa (literature data) were mutually compared by means of multivariate statistical analyses (agglomerative hierarchical cluster analysis and principal component analysis). This was done in order to determine, based on the essential oil profiles, possible mutual relationships of the taxa within the family, especially that of species from the genera Arctostaphylos and Vaccinium. Results of the chemical and statistical analyses pointed to a strong relation between the genera Vaccinium and Arctostaphylos.

Composition of Achillea distans Willd. subsp. distans root essential oil.

Gas chromatography and gas chromatography/mass specteometry analyses of root volatiles of Achillea distans Willd. subsp. distans, collected from wild populations in Serbia, enabled the identification of 185 constituents, accounting for 93.6% of the total oil. Main constituents of the oil were tau-cadinol (17.6%), alismol (14.1%), alpha-cadinol (9.1%) and caryophyllene oxide (5.0%). The root oil was additionally characterised by the presence of five different amides containing the olefinic C(10) acid moieties. This is the first report on A. distans subsp. distans root volatiles and on the occurrence of piperidides and piperideides as essential oil constituents.

The intrasectional chemotaxonomic placement of Hypericum elegans Stephan ex Willd. Inferred from the essential-oil chemical composition.

Here we report, for the first time, the results of detailed GC and GC/MS analyses of the essential oil of a rare taxon in Serbia, Hypericum elegans Stephan ex Willd. One hundred and sixty two constituents identified accounted for 98.6% of the oil. The major components of the oil were undecane (31.9%), alpha-pinene (16.7%), nonane (6.1%), bicyclogermacrene (5.8%), 2-methyloctane (3.7%), and germacrene D (3.6%). Non-terpenoids as chemotaxonomic markers constituted the main fraction of H. elegans oil, whereby n-alkanes were the most abundant contributors of this fraction. Based on these results and previously published ones, we performed an intrasectional multivariate statistical comparison of corresponding essential-oil chemical compositions. Principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) of the data on the volatile profiles of section Hypericum taxa revealed that H. elegans either represents an oil chemotype of its own (AHC) or could be considered related to H. perforatum (PCA).

Synthesis and antimicrobial activity of new 4-heteroarylamino coumarin derivatives containing nitrogen and sulfur as heteroatoms.

Synthesis, spectral analysis and bioactivity of new coumarin derivatives are described in this paper. Eight new coumarin derivatives were synthesized in moderate to good yields by condensation of 4-chloro-3-nitrocoumarin and the corresponding heteroarylamine. The synthesized compounds were tested for their in vitro antimicrobial activity, in a standard disk diffusion assay, against thirteen strains of bacteria and three fungal strains. They have shown a wide range of activity - from one completely inactive compound to medium active ones.

Misidentification of tansy, Tanacetum macrophyllum, as yarrow, Achillea grandifolia: a health risk or benefit?

Tansy, Tanacetum macrophyllum (Waldst. & Kit.) Sch. Bip., is often misidentified by herb collectors as yarrow, Achillea grandifolia Friv. With the former, cases of poisoning induced by its ingestion are well documented, but the latter is widely used for ethnopharmacological purposes. The aim of this study was to estimate, based on the volatile metabolite profiles of the two species, the potential health risk connected with their misidentification. GC and GC-MS analysis of the essential oils hydrodistilled using a Clevenger-type apparatus from A. grandifolia, T. macrophyllum, and two plant samples (reputedly of A. grandifolia, but in fact mixtures of A. grandifolia and T. macrophyllum) obtained from a local market, resulted in the identification of 215 different compounds. The main constituents of A. grandifolia oil were ascaridole (15.5%), alpha-thujone (7.5%), camphor (15.6%), borneol (5.2%) and (Z)-jasmone (6.4%), and of T. macrophyllum oil, 1,8-cineole (8.6%), camphor (6.4%), borneol (9.1%), isobornyl acetate (9.5%), copaborneol (4.2%) and gamma-eudesmol (6.2%). The compositions of the oils extracted from the samples obtained from the market were intermediate to those of A. grandifolia and T. macrophyllum. Significant differences in the corresponding volatile profiles and the literature data concerning the known activities of the pure constituents of the oils, suggested that the pharmacological action of the investigated species (or their unintentional mixtures) would be notably different. It seems, however, that misidentification of T. macrophyllum as A. grandifolia does not represent a health risk and that the absence of the toxic alpha-thujone from T. macrophyllum oil may in fact be regarded as a benefit.

Composition of diethyl ether flower extracts of Lonicera fragrantissima Lindl. & Paxton (caprifoliaceae).

GC and GC-MS analyses of two diethyl ether extracts of Lonicera fragrantissima flowers (extraction times 1 and 20 days) enabled the identification of 61 components that represented ca. 90% of the extract volatiles. 10-Nonacosanol (18.1-24.1%), nonacosane (14.4-15.0%) and the rather rare long-chained fatty acid hexyl esters (octadecanoate, eicosanoate, docosanoate, tetracosanoate, hexacosanoate, octacosanoate and triacontanoate, in total 19.1-19.5%) were among the main constituents of both extracts. However, a number of differences were observed in the chemical composition of the 1 and 20 day extracts, the relative percentage of the iridoid loganetin being the most striking (19.1 and 2.1%, respectively). To the best of our knowledge, this is the first report on the GC behavior of loganetin. It seems that this and the long-chain fatty acid hexyl esters could have chemotaxonomic significance at the generic level.

Fatty acid derived compounds--the dominant volatile class of the essential oil poor Sonchus arvensis subsp. uliginosus (Bieb.) Nyman.

Chemical composition of the essential oil hydrodistilled from aerial parts of Sonchus arvensis subsp. uliginosus is reported for the first time. GC and GC-MS analyses of the oil enabled the identification of 114 components that represented 97.4% of the total oil. Main identified constituents were heneicosane (28.4%), (Z)-3-hexen-1-ol (19.0%), (E)-2-hexen-1-ol (11.6%), 1-eicosanol (7.5%) and tricosane (5.3%). Fatty acid derived compounds ("green leaf' volatiles, alkanes, n-alkenes, n-aldehydes and n-alcohols) were by far predominant (89.4%). A much lower percentage of shikimate metabolites (5.0%), carotenoid-derived compounds (1.7%) and terpenoids (0.9%) has also been detected in the oil. Compositions of the essential oils of S. arvensis subsp. uliginosus and other 18 randomly chosen species, characterized by a wide range of essential oil yields, belonging to different plant genera, were compared using multivariate statistical analysis. The results strongly suggest that the main volatiles of essential oil poor species (yields less then 0.1%) are fatty acid- and carotenoid derived compounds, while essential oil rich taxa (essential oil yields much higher then 0.1%) are generally characterized by the specific production of mono- and sesquiterpenoids, and/or phenylpropanoids.

Synthesis and antimicrobial activity of some new pyrazole derivatives containing a ferrocene unit.

A series of new imines and amines have been synthesized by condensation of 1H-3-ferrocenyl-1-phenylpyrazole-4-carboxaldehyde with the corresponding amines, followed by reduction with sodium borohydride. The synthesized compounds have been screened for their in vitro antimicrobial activity against 11 bacteria and three fungal/yeast strains, using disc diffusion and broth microdilution susceptibility assays. They have shown a wide range of activities, from completely inactive to the highly active compounds.

Chemical composition of the essential oils of serbian wild-growing Artemisia absinthium and Artemisia vulgaris.

The chemical composition of the aerial and root essential oils, hydrodistilled from Artemisia absinthium L. and Artemisia vulgaris L. (wild-growing populations from Serbia), were studied by gas chromatography, gas chromatography-mass spectrometry, and 13C nuclear magnetic resonance. During the storage of plant material under controlled conditions, a significant decrease of essential oil yields (isolated directly after drying and after 1 year of storage) and significant differences in their chemical compositions were observed. A possible mechanism for the observed oil component interconversion has been discussed. The noticeable differences in the chemical composition of the oils isolated from roots and aerial parts of A. absinthium and A. vulgaris were also correlated with the diverging biosynthetic pathways of volatiles in the respective plant organs. The antimicrobial activities against the common human pathogens of all of the isolated oils were tested according to National Committee on Clinical Laboratory Standards. The oils showed a broad spectrum of antimicrobial activity against the tested strains. Therefore, these oils can be used as flavor and fragrance ingredients.

Composition and antimicrobial activity of Equisetum arvense L. essential oil.

The volatile constituents of the sterile stems of Equisetum arvense L. (Equisetaceae) were investigated for the first time using GC, GC/MS and (13)C-NMR. Twenty-five compounds were identified. Hexahydrofarnesyl acetone (18.34%), cis-geranyl acetone (13.74%), thymol (12.09%) and trans-phytol (10.06%) were the major constituents. A disk diffusion method was used for the evaluation of the antimicrobial activity of this oil against a panel of microorganisms (bacteria: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis; fungi: Aspergillus niger and Candida albicans). The 1:10 dilution of the essential oil of Equisetum arvense L. was shown to possess a broad spectrum of a very strong antimicrobial activity against all tested strains.

In vitro antimicrobial activity of extracts of four Achillea species: the composition of Achillea clavennae L. (Asteraceae) extract.

The extracts of aerial parts of Achillea clavennae, Achillea holosericea, Achillea lingulata and Achillea millefolium (hexane:ether:methanol=1:1:1) have been tested for antimicrobial activity in a disk diffusion assay against five bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) and two fungi (Aspergillus niger and Candida albicans). Extracts of all four species possessed a broad spectrum of antimicrobial activity against all tested strains. The composition of the extract of Achillea clavennae, which showed the strongest activity, was investigated and the structures of isolated compounds were elucidated by spectral means (1D and 2D NMR, UV, IR and MS). The extract yielded alkanes, fatty acids, monoterpenes, guaiane sesquiterpenes (rupicolin A and B, 1-deoxy-1alpha-peroxy-rupicolin A and B), and flavonoids (apigenin and centaureidin). This study confirms the ethnopharmacological use of plants from this genus and places Achillea clavennae L. on the same level as the recognized Achillea millefolium.