Mikrobiološka transformacija sintetičkog laktona benzofuranskog tipa

The aim of this work was the investigation of the biotransformation ability of a synthetic benzofurane type g-lactone. This workwas basedon the microbiological reactions of Aspergillus niger, Saccharomyces cerevisiae, Bacillus mycoides, Agrobacterium tumefa- ciens,Pseudomonas glicinea and Pseudomonas fluorescens to obtain newactive derivatives. Four biotransformation products were determined. The lactone was used for two purposes, as an additive for the nutrient substrate and as a source of organic carbon.Cilj ovog rada je ispitivanje mogućnosti biotransformacije benzofuranskog derivata, sa a-metilen-g-butirolaktonskom strukturnom jedinicom, sa različitim sojevima mikroorganizama: Aspergillus niger, Saccharomyces cerrevisiae, Bacillus mycoides, Agrobacterium tumefaciens, Pseudomonas glicinea i Pseudomonas fluorescens u cilju dobivanja novih jedinjenja sa specifičnijom antimikrobnom aktivnošću. Takodje izolovani i identifikovani proizvodi su ukazali i potvrdili osnovne biodegradacione puteve ispitivanog laktona

Изоловање и антимикробна активност антрахинона неких врста лишајева рода Xanthoria

The isolation of six anthraquinones erythroglaucin, physcion, xanthorin, emodin, fallacinal, 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 and fungal and selective activity against some phytopathogenic bacterial species.Из три врсте лишајева рода Xanthoriа (X.fallax, X.elegans and X.policarpa) изоловани су следећи антрахинони : еритроглауцин, фисцион, ксанторин, емодин, фалацинал и фалацинол.Тестирани антрахинони показују широк спектар антифунгалне активности и селективну активност према неким врстама фитопатогених бактерија

Dropwort (Filipendula hexapetala Gilib.): potential role as antioxidant and antimicrobial agent

The aim of this study was to investigate the antioxidant activity of the methanolic extracts of Filipendula hexapetala Gilib. aerial parts (FHA) and roots (FHR) and their potential in different model systems, as well as antimicrobial activity. According to this, a number of assays were employed to evaluate the antioxidant and antimicrobial potential of F. hexapetala extracts. In addition, the antioxidant activity assays in different model systems were carried out, as well as pH, thermal and gastrointestinal stability studies. The phenolic compounds contents in FHA and FHR were also determined. The results showed that F. hexapetala extracts had considerable antioxidant activity in vitro and a great stability in different conditions. The extracts exhibited antimicrobial activity against most of the tested bacterial and fungal species. Also, the extracts contain high level of phenolic compounds, especially aerial parts extract

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

Secondary metabolites from the aerial parts of Centaurea pannonica (Heuff.) Simonk. from Serbia and their chemotaxonomic importance

The non polar extract of Centaurea pannonica (Heuff.) Simonk., growing wild in Serbia, was studied and twenty-five compounds including 14 sesquiterpene lactones, 7 flavonoids, 3 lignans and 1 phenylpropanoid glycoside were isolated. All compounds were isolated for the first time from this species. Among them, one germacranolide 2α-hydroxy, 8-dehydroxy 15-O-methacrylate salonitenolide (1) and two guai-anolides 2α,8α-dihydroxy- dehydrocostus lactone (2) and pannonin (3) are new natural compounds. The structures of the compounds were established on the basis of spectroscopic analyses (UV, IR, HREIMS and 1D & 2D NMR). The chemical profile of C pannonica, which belongs to the "Centaurea jacea" group, was compared to previously studied taxa of the same group and used to assess the phylogenetic relationships in the group. © 2013 Elsevier Ltd. All rights reserved

Chemical composition and antimicrobial activity of essential oils from Centaurea pannonica and C. jacea

The chemical composition and antimicrobial activity of the essential oils obtained by hydrodistillation from Centaurea pannonica (Heufel) Simonkai and C. jacea L. (Asteraceae), were investigated. The essential oils were analyzed by GC and GC-MS. Forty five and twenty nine compounds were identified in the two oils, respectively. C. pannonica oil was rich in fatty acids (43.7%), with 9-octadecanoic acid (34.0%) and (Z,Z)-9,12-octadecadienoic acid (8.6%) as the major compounds. In contrast, the essential oil of C. jacea was dominated by oxygenated sesquiterpenes (43.2%), among which caryophyllene oxide (23.5%) and spathulenol (8.9%) were the major constituents. However, the oil was also characterized by an important fatty acid fraction (15.5%), with 9-octadecanoic acid (8.9%) and hexadecanoic acid (6.6%) being the main components. The antimicrobial activities of the essential oils were evaluated by the microdilution method against three Gram-positive and three Gram-negative bacteria, and one yeast. Both oils exhibited significant antimicrobial activity, especially against Gram-positive bacteria

Reaction of formaldehyde with mer-(ethylenediamine)(glycylglycinato)nitrocobalt(III). Crystal structure of mer-(ethylenediamine)[N-((5,6-dihydro-5,5-bis(hydroxymethyl)-1,3-oxazin-4-yl)- carbonyl)glycinato]nitrocobalt(III) trihydrate

Three new compounds result from the reaction of mer-[Co(NH2CH2CONCH2CO2)NO 2(en)] with formaldehyde in alkaline aqueous solution: mer-(ethylenediamine)[N-((5,6-dihydro-5,5-bis(hydroxymethyl)-1,3-oxazin-4-yl) carbonyl)glycinato]nitrocobalt(III) trihydrate (mer-[Co{(CH2OH)2CCH2OCH 2N=CCONCH2CO2}NO 2(en)]·3H2O), mer-(ethylenediamine)[N-(((methylimino)methyl)carbonyl)glycinato] nitrocobalt(III) (mer-[Co(CH3N=CHCONCH2CO2)NO2(en)]), and mer-(ethylenediamine)(N-methylideneglycylglycinato)nitrocobalt(III) (mer-[Co(CH2=NCH2CONCH2CO2)NO 2(en)]). They were separated by adsorption chromatography on a cationic exchanger, in the hydrogen form, and characterized by elemental analysis, electronic spectroscopy, and 1H and 13C NMR spectroscopy. The structure of mer-[Co{(CH2OH)2CCH2OCH 2N=CCONCH2CO2)-NO 2(en)]·3H2O was determined by X-ray crystallography. It crystallizes in the monoclinic space group P21/n in a unit cell of dimensions a = 8.843(1) Å, b = 26.809 (2) Å, c = 8.910 (1) Å, β = 115.91 (2)°, V = 1899.9 Å3, and ρcalcd = 1.62 g cm-3, with Z = 4. Refinement converged to R = 0.031 for 3260 independent observed (I/σ(I) > 3) reflections. The 1,3-oxazine derivative is tridentate, coordinated through carboxylato oxygen, peptide nitrogen, and imino nitrogen atoms. The equatorially disposed ligand forms with cobalt three fused rings, two five-membered chelates, and one six-membered heterocyclic ring. © 1990 American Chemical Society

Phytochemical screening and biological activity of extracts of plant species Halacsya sendtneri (Boiss.) Dörfl.

This study is aimed at examining total polyphenol, flavonoid, gallotannin and condensed tannins content in acetone, chloroform, ethyl acetate and petroleum ether extracts of Halacsya sendtneri (Boiss.) Dörfl., their antimicrobial and antioxidant activities, as well as identifying and quantifying the phenolic components. The antioxidant activity is consistent with the results of total quantity of phenolic compound. The results showed that the acetone extract of plant species Halascya sendtneri (Boiss.) Dörfl. possessed the highest antioxidant activity. IC50 values were determined: 9.45��1.55 μg/mL for DPPH free radical scavenging activity, 13.46±1.68 μg/mL for inhibitory activity against lipid peroxidation, 59.11±0.83 μg/mL for hydroxyl radical scavenging activity and 27.91±0.88 μg/mL for ferrous ion chelating ability. The antimicrobial activity was tested using broth dilution procedure for determination of the minimum inhibitory concentration (MIC). The MICs were determined for 8 selected indicator strains. All of the extracts showed strong to moderate strong antimicrobial activity. The phenolic composition of Halacsya sendtneri extracts was determined by the HPLC method. The dominant phenolic compound in acetone, chloroform and ethyl acetate extract is rosmarinic acid. Ethyl acetate extract was also abundant in p-hydroxybenzoic acid and ferulic acid. The main compounds in petrol ether extract were chlorogenic acid and quercetin