Antioxidant activity, total phenolic content and flavonoid concentrations of different plant parts of Teucrium polium L. subsp. polium

Total phenolic content, concentration of flavonoids and in vitro antioxidant activity of twenty different extracts from the whole plant and plant parts (leaves, flowers and stems) of Teucrium polium were determined. The total phenolic contents ranged between 14.57 to 157.84 mg of GaA/g of extract. The concentrations of flavonoids varied from 6.48 to 139.87 mg of Ru/g of extract. Antioxidant activity was determined in vitro using DPPH reagent and expressed as concentration of each extract required to inhibit radical by 50% (IC50) values that ranged from 26.30 to 2190.75 µg/ml. The methanolic leaves extract contain the greatest concentration of phenolic compounds (157.84 mg of GaA/g) and showed strong antioxidant activity (IC50 = 26.30 µg/ml). Ginkgo and Green tea extracts were analyzed for comparison, and the results indicated that some extracts of T. polium were equal in activity with Ginkgo or Green tea and some appeared to have greater activity. The obtained results suggest strong antioxidant activity and large contribution of separate analysis for the maximum exploitation of active phenolic compounds from T. polium. Based on this information, plant parts of this plant are natural sources of antioxidant substances of high importance

Genotoxic potential of Cotinus coggygria Scop. (Anacardiaceae) stem extract in vivo

The intention was to evaluate the possible in vivo genotoxic potential in different cell-types, of a methanol extract obtained from the plant stem of Cotinus coggygria Scop., using the sex-linked recessive lethal (or SLRL) test and alkaline comet assay. The SLRL test, revealed the genotoxic effect of this extract in postmeiotic and premeiotic germ-cell lines. The comet assay was carried out on rat liver and bone marrow at 24 and 72 h after intraperitoneal administration. For genotoxic evaluation, three concentrations of the extract were tested, viz., 500, 1000 and 2000 mg/kg body weight (bw), based on the solubility limit of the extract in saline. Comet tail moment and total scores in the group treated with 500 mg/kg bw, 24 and 72 h after treatment, were not significantly different from the control group, whereas in the groups of animals, under the same conditions, but with 1000 and 2000 mg/kg bw of the extract, scores were statistically so. A slight decrease in the comet score and tail moment observed in all the doses in the 72 h treatment, gave to understand that DNA damage induced by Cotinus coggygria extract decreased with time. The results of both tests revealed the genotoxic effect of Cotinus coggygria under our experimental conditions

Acyloxylation of Cyclic Enones: Synthesis of Densely Oxygenated Guaianolides

The α′-acyloxylation of cyclic enones with linear carboxylic acids is described. The reaction is promoted by KMnO4 in the presence of a carboxylic acid and its corresponding carboxylic anhydride. The optimization of the reaction has been carried out using the statistical methodology known as design of experiments. The optimized reaction conditions have been evaluated in terms of substrate scope and compatibility with different functional groups. The methodology has been applied to the synthesis of densely oxygenated guaianes and guaianolides

Actividad antibacteriana sinergística in vitro y conservantes de Melissa officinalis L.

The aim of this study was to investigate the antibacterial activity of aqueous, ethanol and ethyl acetate extracts of the species Melissa officinalis L. and their in vitro synergistic action with preservatives, namely: sodium nitrite, sodium benzoate and potassium sorbate against selected food spoiling bacteria, for a potential use in food industry. Synergistic action was noticed in almost every combination between plant extracts and preservatives. This work showed that the active compounds from ethanol, ethyl acetate and aqueous extracts of Melissa officinalis L. significantly enhanced the effectiveness of tested preservatives. Synergism was established at plant extract and preservative concentrations corresponding to 1/4 and 1/8 minimal inhibitory concentration values, which indicated the possibility of avoiding the use of higher concentrations of tested preservatives.El objetivo de este estudio fue investigar, para un uso potencial en la industria alimentaria, la actividad antibacteriana de extractos en agua, en etanol y en acetato de etilo de Melissa officinalis L. y su acción sinergística in vitro con los conservantes nitrito sódico, benzoato sódico y sorbato potásico sobre una selección de bacterias que dañan los alimentos. Se detectó una acción sinergística en casi todas las combinaciones entre los extractos de las plantas y los conservantes. Este trabajo muestra que los componentes activos de los extractos en etanol, acetato de etilo y agua de Melissa officinalis L. elevaron significativamente la eficacia de los conservantes analizados. El sinergismo fue establecido a concentraciones de los extractos de plantas y de los conservantes correspondientes a 1/4 y 1/8 de los valores de concentración inhibitoria mínima, lo que indica que se puede evitar utilizar concentraciones más elevadas de estos conservantes

Microbiological degradation of a synthetic benzofurane type lactone

160-165A benzofurane type lactone 4 incorporating an -methylene--butyrolactone moiety has been synthesized. The key steps involved are the Michael condensation of 4-dichloromethyl-4-methyl-2,5-cyclohexadienone 1 with dimethyl malonate and acetoxylation of 4-dichloromethyl-5-carboxymethyl-4-methyl-2-cyclohexenone 2 with lead (IV) acetate in BF3 -etherate which are indicative of the general route to -lactone. Microbial degradations of the synthetic benzofurane type lactone 4 have also been studied using Aspergillus niger. Saccharomyces cerevisiae, Bacillus mycoides, Agrobacterium and The lactone acts both as an additive for the nutrient substrate and as a source of organic carbon

In vitro synergistic antibacterial activity of Melissa officinalis L. and some preservatives

The aim of this study was to investigate the antibacterial activity of aqueous, ethanol and ethyl acetate extracts of the species Melissa officinalis L. and their in vitro synergistic action with preservatives, namely: sodium nitrite, sodium benzoate and potassium sorbate against selected food spoiling bacteria, for a potential use in food industry. Synergistic action was noticed in almost every combination between plant extracts and preservatives. This work showed that the active compounds from ethanol, ethyl acetate and aqueous extracts of Melissa officinalis L. significantly enhanced the effectiveness of tested preservatives. Synergism was established at plant extract and preservative concentrations corresponding to 1/4 and 1/8 minimal inhibitory concentration values, which indicated the possibility of avoiding the use of higher concentrations of tested preservatives.El objetivo de este estudio fue investigar, para un uso potencial en la industria alimentaria, la actividad antibacteriana de extractos en agua, en etanol y en acetato de etilo de Melissa officinalis L. y su acción sinergística in vitro con los conservantes nitrito sódico, benzoato sódico y sorbato potásico sobre una selección de bacterias que dañan los alimentos. Se detectó una acción sinergística en casi todas las combinaciones entre los extractos de las plantas y los conservantes. Este trabajo muestra que los componentes activos de los extractos en etanol, acetato de etilo y agua de Melissa officinalis L. elevaron significativamente la eficacia de los conservantes analizados. El sinergismo fue establecido a concentraciones de los extractos de plantas y de los conservantes correspondientes a 1/4 y 1/8 de los valores de concentración inhibitoria mínima, lo que indica que se puede evitar utilizar concentraciones más elevadas de estos conservantes

Isolation and antimicrobial acitivity of anthraquinones from some species of the lichen genus Xanthoria

The isolation of six anthraquinones, erythroglaucin, physcion, xanthorin, emodin, fallacinal and teloschistin, from three species of the lichen genus Xanthoria (X. fallax, X. elegans and X. policarpa) is reported. Physcion is the dominant anthraquinone in all species. the anthraquinones showed broad-spectrum antifingal activity and selective activity against some phytopathogenic bacterial species

The preparation of an isoxazole derivative of 4-hydroxycoumarin

A method for preparation of an isoxazole derivative of 4-hydroxycoumarin, 3-phenyl-5-(4-hydroxy-3-coumarinyl)-isoxazole has been described. The reaction sequence includes addition of bromine to 3-cinnamoyl-4-hydroxycoumarin, and the subsequent treatment of the obtained dibromo derivative with 2 equivalents of sodium azide. Due to steric reasons, the azido group is introduced in the beta-position with respect to the side chain carbonyl group, so that an isoxazole ring can be formed. The total yield of the reaction was 58%

The preparation of an isoxazole derivative of 4-hydroxycoumarin

A method for preparation of an isoxazole derivative of 4-hydroxycoumarin, 3-phenyl-5-(4-hydroxy-3-coumarinyl)-isoxazole has been described. The reaction sequence includes addition of bromine to 3-cinnamoyl-4-hydroxycoumarin, and the subsequent treatment of the obtained dibromo derivative with 2 equivalents of sodium azide. Due to steric reasons, the azido group is introduced in the beta-position with respect to the side chain carbonyl group, so that an isoxazole ring can be formed. The total yield of the reaction was 58%