Chemical composition and biological activities of the extracts and secondary metabolites of lichens belonging to the genus Usnea, Parmeliaceae

Lichens represent a promising source of antimicrobial, cytotoxic and antioxidant agents. Their great pharmacological potential lies in the fact that they represent specific symbiotic organisms and thus possess natural roles allowing them to be highly adaptable to different environmental conditions. On the other hand, stated biological activities of lichens with prospective medicinal significance may be connected to their long-term use in traditional treatment of various ailments. Genus Usnea from the Parmeliaceae family is certainly one of the best studied in terms of chemical composition and biological properties of its extracts and/or isolated compounds. In the first part of the study, a detailed review of literature has been performed yielding a detailed report on the investigations of biological activities of the lichens belonging to this genus. In the second part of the study, chemical composition of the lichens from the genus was described and, additionally, a survey of the biological properties of the most representative secondary metabolites in these lichens has been reported. It could be concluded that the extracts and/or isolated compounds from the lichens belonging to the genus Usnea may be considered a valuable source of prospective drug candidates with potential clinical relevance

Supercritical carbon dioxide hops extracts with antimicrobial properties

Extracts obtained from hops (Humulus lupulus L., Cannabaceae) by supercritical fluid extraction (SFE), SFE followed by isomerization, as well as by conventional technique, were investigated for their chemical composition and antibacterial activity against selected foodborne pathogens and microorganisms capable to cause the food spoilage. The antibacterial activity of the extracts was compared with the antibacterial activity of xanthohumol, compound known for its broad pharmacological properties, isolated from the raw material remained after the SFE. Xanthohumol (XH, 96%) proved to posses the most prominent activity against all the tested strains, with the MIC values ranged between 2.5 and 20 mu g mL(-1). Supercritical hops extract and potassium isomerized supercritical hops extract showed strong antibacterial activity against the tested strains as well. Escherichia coli was not affected by the extracts, meaning that their oral admission would not cause the same problem as antibiotic application in intestinal flora. The chemical composition of the investigated hops extracts was analysed by GC-MS. Contents of a-acids, beta-acids, iso-alpha-acids and xanthohumol in the samples were determined by HPLC

Evaluation of Anticancer and Antioxidant Activity of a Commercially Available CO2 Supercritical Extract of Old Man's Beard (Usnea barbata)

There is a worldwide ongoing investigation for novel natural constituents with cytotoxic and antioxidant properties. The aim of this study was to investigate chemical profile and stated biological activities of the supercritical CO2 extract (SCE) of old man's beard compared to the extracts obtained using the conventional techniques (Soxhlet extracts and macerate). The most abundant compound identified was usnic acid, which content was inversely proportional to the polarity of the solvent used and was the highest in the SCE, which was the sample revealing the highest cytotoxic activity in tested tumor cell lines (B16 mouse melanoma and C6 rat glioma), with lower IC50 values compared to pure usnic acid. Further investigations suggested both SCE and usnic acid to induce apoptosis and/ or autophagy in B16 and C6, indicating higher cytotoxicity of SCE to be related to the higher degree of ROS production. A good correlation of usnic acid content in the extracts and their antioxidant capacity was established, extricating SCE as the most active one. Presented results support further investigations of SCE of old man's beard as a prospective therapeutic agent with potential relevance in the treatment of cancer and/ or in oxidative stress-mediated conditions

Supplementary data for the article: Brasanac-Vukanovic, S.; Mutic, J.; Stankovic, D. M.; Arsic, I.; Blagojevic, N.; Vukasinovic-Pesic, V.; Tadic, V. M. Wild Bilberry (Vaccinium Myrtillus l., Ericaceae) from Montenegro as a Source of Antioxidants for Use in the Production of Nutraceuticals. Molecules 2018, 23 (8). https://doi.org/10.3390/molecules23081864

Supplementary material: [https://doi.org/10.3390/molecules23081864]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2221

Wild Bilberry (Vaccinium myrtillus L., Ericaceae) from Montenegro as a Source of Antioxidants for Use in the Production of Nutraceuticals

The aim of this study was to establish correlation of chemical composition and antioxidant activity of bilberry plants from Montenegro. Total phenolic, tannin, flavonoid, procyanidin and anthocyanin contents were determined in fruits and leaves extracts using spectrophotometric methods, while the measurements of metal content was carried out in an Inductively Coupled Atomic Emission Spectrometer. Qualitative and quantitative analyses of major phenolics were achieved by HPLC. In the investigated extracts, the most abundant phenolic was chlorogenic acid, followed by protocatechuic acid, while resveratrol, isoquercetin, quecetin and hyperoside were also present in significant quantities. Antioxidant potential was evaluated using two in vitro assays-FRAP and DPPH-being in the accordance with the cyclic voltammetry tests, performed as well. The results revealed that all the investigated extracts were rich in phenolic and essential mineral constituents, with significant antioxidant activity, depending on the polyphenolic and mineral contents, which was confirmed by principal component analysis.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3314

Supplementary data for article: Vukanović, S. B.; Tadić, V. M.; Blagojević, N.; Pešić, V. V.; Durdić, S.; Stanković, M.; Mutić, J. Element Accumulation Capacity of Vaccinium Myrtillus from Montenegro: Comparison of Element Contents in Water and Ethanol Extracts of Bilberry Plant Parts. Archives of Biological Sciences 2019, 71 (1), 145–157. https://doi.org/10.2298/ABS181004056B

Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3055

Element accumulation capacity of Vaccinium myrtillus from Montenegro: Comparison of element contents in water and ethanol extracts of bilberry plant parts

Bilberry (Vaccinium myrtillus L., Ericaceae) is a rich source of different mineral elements that are important as essential trace elements, or that can be potentially toxic, depending on their concentration. The contents of sixteen elements: the major (Al, Ca, Fe, K and Mg) and trace elements (As, Ba, Cd, Co, Cu, Cr, Mn, Ni, Pb, Sr and Zn) in roots, stems, leaves and fruits of bilberry and the corresponding soil substrate were determined in order to investigate element mobility and availability in soil. Soil was subjected to sequential extraction procedure as proposed by the Community Bureau of Reference in order to fractionate acid-soluble/exchangeable, reducible, oxidizable and residual fractions. Analysis of water and ethanol extracts of bilberry aerial parts revealed a significant transfer of elements during the extraction procedure, with corresponding extraction coefficient values of up to 95.12%. Results showed that bilberry fruits could serve as a good dietary source of essential elements for humans, especially Mn and Cu.Supplementary data: [http://cherry.chem.bg.ac.rs/handle/123456789/3057