Browsing by Author "Bogdanovic-Dusanovic G."

Now showing 1 - 3 of 3

Chemical composition, antioxidant, and antimicrobial activities of lichen Umbilicaria cylindrica (L.) delise (Umbilicariaceae)
(2012) Manojlovic, Nedeljko; Vasiljević, Perica; Mašković, Pavle; Juskovic, Marina; Bogdanovic-Dusanovic G.
The phytochemical analysis of methanol and chloroform extracts of Umbilicaria cylindrica was determined by HPLC-UV method. The predominant phenolic compound in both extracts was depsidone, salazinic acid (1). Besides salazinic acid, the tested extracts of U. cylindrica contain norstictic acid (2), methyl-β-orcinol carboxylate (3), ethyl haematommate (4), atranorin (5), and usnic acid (6), in different amounts and relations. The lichen extracts showed comparable and strong antioxidant activity, exhibited higher DPPH and hydroxyl radical scavengings, chelating activity, and inhibitory activity towards lipid peroxidation. The lichen extracts demonstrated important antimicrobial activity against eight strains with MIC values from 15.62 to 62.50μg/mL. This is the first report of the detail chemical composition and antioxidant activity of the lichen Umbilicaria cylindrica, and the results suggest that this lichen can be used as a new source of the natural antioxidants and the substances with antimicrobial features. Copyright © 2012 Nedeljko T. Manojlovic et al.
Some Biochemical Changes in the Lichen Evernia prunastri Exposed to Atmospheric Pollutants
(2021) Bogdanovic-Dusanovic G.; Manojlovic, Nedeljko; Trajković R.; Pejčinović D.; Tomović, Jovica
Lichens have played an important role in air pollution studies as a bioindicator. The lichen Evernia prunastri was transplanted from a relatively unpolluted site in Serbia to six more polluted sites for a period of six months. The total proline contents, peroxidase activity, and content of secondary metabolites were determined before and after transplantation. Our findings show that relative high concentration of sulfur dioxide and other pollutants in the habitat of the above lichen cause oxidative stress, which promoted an increase in proline contents and changes peroxidase activity of thalli. The accumulation of proline was increased several times for lichen species. Atmospheric pollution caused a decrease in the activity of peroxidase in this lichen. HPLC analysis showed that the quantity of secondary metabolites was increased in the samples after transplantation to more polluted sites. Our results show that secondary metabolites might have an important role in the protection against atmospheric pollutants.
The isolation, analytical characterization by HPLC-UV and NMR spectroscopy, cytotoxic and antioxidant activities of baeomycesic acid from Thamnolia vermicularis var. subuliformis
(2011) Manojlovic, Nedeljko; Vasiljević, Perica; Bogdanovic-Dusanovic, Gordana; Marković, Zoran; Najman, Stevo; Nikolić, Dragan
The aim of this work was the analytical characterization of the β-orcinol depside, baeomycesic acid in lichens extracts. The extract of Thamnolia vermicularis var. subuliformis was analyzed by two different methods, namely HPLC-UV and 1H-NMR analysis. The results showed that baeomycesic acid was the most abundant depside in the lichens. These results could be of use for rapid identification of this metabolite in other lichen species. Besides baeomycesic acid, three depsides and one monocyclic phenolic compound were isolated from the lichen extract on the chromatographic column. The structure of baeomycesic acid was confirmed by HPLC-UV and spectroscopic methods. In addition, antioxidant and cytotoxic activities of baeomycesic acid were determined. The result of the testing showed that baeomycesic acid exhibited a moderate radical scavenging activity (IC50 = = 602.10±0.54 μg/mL) and good cytotoxic activity. This is the first report of detailed analytical characterization and isolation, as well as antioxidant and cytotoxic activities of baeomycesic acid from Thamnolia vermicularis. These results may be helpful in future industrial production of herbal medicines that include this important natural product.