Gordana Stojanović

Even carbon number predominance of plant wax n-alkanes: a correction

Abstract The distributions of n-alkanes of four species of Micromeria have the conventional higher plant pattern of high carbon preference index (CPI) and odd-numbered carbon dominance (maxima at n-C31 or n-C33), rather than the even-numbered predominance previously reported (Palic, R., Ristic, N., Simic, N., Kitic, D., Kapetanovic, R., 1997. The alkanes from some plants of Micromeria genus. Journal of the Serbian Chemical Society 62, 619–622). The stable carbon isotope ratio values (δ13C) of the individual n-alkanes (−38 to −34‰) are typical of C3 plants. Homologous series of odd-numbered predominant iso-alkanes (i-C27 to i-C35) and even-numbered predominant anteiso-alkanes (a-C27 to a-C35) are also present (8 to 18% of the total identified alkanes) and have similar carbon isotopic ratios (−36.8 to−35.1‰).

Do other Hypericum species have medical potential as St. John's wort (Hypericum perforatum)?

Among 484 Hypericum L. (Guttiferae/Hypericaceae) species, widespread in warm temperate areas throughout the world, only H. perforatum is widely used in official medicine. Hypericum perforatum has been reported as an antidepressant, antiviral, antimicrobial, anti-inflammatory, and a healing agent. The main constituents of the Hypericum species are naphthodianthrones, primarily represented by hypericin and pseudohypericin, phloroglucinol derivatives, especially hyperforin, and flavonoids, such as quercetin, quercitrin, hyperoside and rutin. Hypericin and pseudohypericin have been found to possess antiretroviral activity. Hyperforin may also have an important contribution to the antidepressant activity of Hypericum extracts. The content of the above active constituents in some Hypericum species is higher than in H. perforatum. Also, a number of studies of the biological activities of Hypericum species have shown that the most recognized species of this genus, H. perforatum, was not the most active. Comprehensive analysis of the published research on the chemical composition and biological activity, showed that H. richeri has a similar pharmacological potential as St. Jons wort. The species, with high content of naphtodianthrones,which might be used against viruses and retroviruses, are: H. androseamum,H. annulatum, H. barbatum, H. boissieri, H. elegans, H. hirsutum, H. hyssopifolium, H. humifusum, H. montanum. H. montbretii, H. triquetrifolium, H. richeri, H. rochelii, H. rumeliacum, H. thasium, andH. patulum. Very few species (e.g. H. inodorum and H. moseranum) contained the similar amounts of hyperforine as H. perforatum. Since hyperforin was recognized as one of the most crucial components for the antidepressive activity, it seems that H. perforatum barely has an alternative for this purpose. Plant species containing considerable amounts of other acylphloroglucinol derivatives have the potential to demonstrate antibacterial and cytotoxic activity. Some of these species are: H. sampsonii, H. ascyron, H. foliosum, H. geminiflorum and H. scabrum. However, only a few studies concerning the activity of extracts and isolated compounds were done in vivo. Also, data on the safe usage of Hypericum constituents as phytotherapeutics are scarce. Since some of Hypericum species are scarcely distributed or endemic as well as some of the secondary metabolites are presented in very small amounts, bio-production, especially endophytes, could represent an abundant and reliable source of pharmacologically active metabolites of Hypericum species for exploitation in pharmaceutical industry.

Chemical composition and antimicrobial activity of the essential oil and CO2 extracts of semi-oriental tobacco, Otlja.

A study of the chemical composition of essential oil and CO2 extracts of the middle and upper leaf positions of the oriental tobacco Prilep was performed using GC and GC–MS. The major constituents were: in the essential oil, neophytadiene and solanone; in CO2 extract I, neophytadiene; and in CO2 extract II, nicotine, nonacosane and solanesol. The antimicrobial activity of the essential oil and CO2 extracts were investigated against the microorganisms: Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The results showed that oil from the middle leaves showed greater activity than the oil of the upper leaves. Both leaf oils mainly showed greater activity than CO2 extracts. Copyright

Wild fire impact on copper, zinc, lead and cadmium distribution in soil and relation with abundance in selected plants of Lamiaceae family from Vidlic Mountain (Serbia)

Fire has been considered as an improving factor in soil quality, but only if it is controlled. Severe wild fire occurred in the summer 2007 on the Vidlic Mountain (Serbia) overspreading a huge area of meadows and forests. Main soil characteristics and content of heavy metals (Cu, Pb, Cd, Zn) in different fractions obtained after sequential extraction of soil from post-fire areas and from fire non disturbed areas were studied. In four plant species of Lamiaceae family (Ajuga genevensis L., Lamium galeobdolon (L.) L., Teucrium chamaedrys L., Acinos alpinus (L.) Moench.), that grow in typical habitats of the mountain, distribution of heavy metals in aerial parts and roots was investigated too. For all samples from post-fire area cation exchange capacity and soil organic matter content are increased while rH is decreased. Fire caused slightly increased bioavailability of the observed metals but more significant rise happened in metal amounts bound to oxides and organics. The plants showed variable behavior. T. chamaedrys collected on the post-fire area contained elevated concentrations of all analyzed metals. A. alpinus showed higher phytoaccumulation for Zn and Cd, while the other two plant species for Pb and Cd in the post-fire areas.

Reducing power and radical scavenging activity of four Parmeliaceae species

The methanol extracts of four Parmeliaceae lichens (Hypogymnia physodes, Evernia prunastri, Flavoparmelia caperata and Parmelia sulcata) were screened for antioxidant properties and total phenol content. The H. physodes extract was the most effective at reducing iron(III) and scavenging 1,1-diphenyl-2-picrylhydrazyl radicals, while the P. sulcata extract was the most effective in reducing molybdenum(VI) in an acidic medium. The E. prunastri and H. physodes extracts contained more Folin-Ciocalteu reagent reactive substances than the F. caperata and P. sulcata extracts. Significant activity of the H. physodes extract in DPPH and reducing Fe(III) assays suggest that this lichen can be considered as a potential source of antioxidants.

Xanthine Oxidase: Isolation, Assays of Activity, and Inhibition

Xanthine oxidase (XO) is an important enzyme catalyzing the hydroxylation of hypoxanthine to xanthine and xanthine to uric acid which is excreted by kidneys. Excessive production and/or inadequate excretion of uric acid results in hyperuricemia. This paper presents a detailed review of methods of isolation, determination of xanthine oxidase activity, and the effect of plant extracts and their constituents on it. Determining the content and activities of XO can be used for diagnostic purposes. Testing inhibition of XO is important for detection of potentially effective compounds or extracts that can be used to treat diseases that are caused by increased activity of XO. In vitro bioassays are used to examine test material for XO inhibition, as inhibitors of XO may be potentially useful for the treatment of gout or other XO induced diseases. Several authors reported on the XO inhibitory potential of traditionally used medicinal plants.

Effect of four lichen acids isolated from Hypogymnia physodes on viability of rat thymocytes.

Four lichen acids, physodalic acid (F1), physodic acid (F2), 3-hydroxyphysodic acid (F3), and isophysodic acid (F4), were isolated from Hypogymnia physodes methanol extract using preparative reversed-phase high performance liquid chromatography and their structures were determined by UV, MS, (1)H NMR and (13)C NMR. This is the first report on the isolation of F4 from H. physodes. Isolated rat thymocytes were cultivated with increasing F1-F4 concentrations (0.1, 1, 10μg/well) and proliferative activity, viability, ROS (reactive oxygen species) production and MMP (mitochondrial membrane potential) disturbances were evaluated. Obtained results show significantly decreased thymocytes proliferation was observed when cells were treated with F1 (1μg, p<0.05; 10μg; p<0.001), F2 (10μg, p<0.05) and F3 compound (10μg, p<0.05). Significantly increased cytotoxicity was detected when cells were incubated with F1 (1μg, p<0.05; 10μg, p<0.01), F2 (10μg, p<0.05) and F3 compound (10μg, p<0.001). Increased H2DCF-DA fluorescence intensity, when cells were treated with F1 (1μg, p<0.001; 1μg, p<0.01; 10μg, p<0.001) and F2 (1μg, p<0.05; 10μg, p<0.01) compound, indicating the increase of intracellular ROS production. Simultaneously, increased ROS levels were followed with significantly decreased MMP when thymocytes were cultivated with F1 (0.1μg, p<0.001; 1μg, p<0.001; 10μg, p<0.001) and F2 compound (10μg, p<0.001). Thymocytes exposure to increased (0.1, 1, 10μg) concentrations of F3 and F4 compounds did not result with significant alterations in MMP and intracellular ROS production. We have shown that higher F1 and F2 concentrations induce thymocytes toxicity mainly through induction of oxidative stress, while cytotoxicity effect of F3 is followed with altered antioxidant/oxidant balance. The rigid 11H-dibenzo[b,e][1,4]dioxepin-11-one ring in the depsidone structure may play a important role for the examined biological activities.

Composition and Antibacterial Activity of Achillea crithmifolia and Achillea nobilis Essential Oils

Abstract The composition of the essential oils of Achillea crithmifolia and Achillea nobilis was analyzed by GC and GC/MS. The main compounds of the A. crithmifolia essential oil were camphor (27.6%), 1,8-cineole (26.5%) and trans-chrysanthenyl acetate (18.8%), while the most abundant compounds in the A. nobilis oil were α-thujone (25.7%), artemisia ketone (14.8%), borneol (9.9%) and camphor (8.2%). The antibacterial activity of oils was tested for the first time. Both examined oils showed very strong antibacterial activity against all tested microorganisms (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus).

Antimicrobial Activity of Nepeta rtanjensis Essential Oil

Abstract The antimicrobial activity and the composition of the essential oil of aerial parts of Nepeta rtanjensis Diklić et Milojević wild growing and cultivated in Serbia were evaluated. The main compound in both samples was characterized as 4aα,7α,7aβ-nepetalactone with 83.6% (wild) and 77.9% (cultivated). α-Copaene, germacrene D and δ-cadinene were present less than 5% in the oils. The antimicrobial activity of the oils was investigated by disk diffusion method. The oil-ethanol solution in three dilutions, tested against fve bacteria and a fungus, was effective towards all bacteria but not against Aspergillus niger. The oils showed bacteriostatic activity even in 1:60 dilution.

Essential Oil Composition of Four Achillea Species from the Balkans and Its Chemotaxonomic Significance

The chemical composition of the essential oils of Achillea clavennae L., Achillea holosericea Sibth. & Sm., Achillea lingulata W. & K., and Achillea millefolium L. from the Balkans was determined by GC and GC/MS analyses. The main components were 1,8-cineole in A. holosericea, camphor in A. clavennae, β-pinene in A. millefolium, and τ-cadinol in A. lingulata. A detailed chemotaxonomic discussion is presented.