Bioactive Constituents from Lichens

Here we investigate antioxidant and antimicrobial activities of the acetone extract of the Cladonia rangiferina and their fumarprotocetraric acid. Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power and determination of total phenolics. As a result, fumarprotocetraric acid had larger free radical scavenging activity with (IC50 = 228.46 μg/mL). Tested samples also had effective reducing power and superoxide anion radical scavenging. Total phenolic content was determined as pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the MIC, where most active was fumarprotocetraric acid with MIC values ranging from 0.03 to 0.25 μg/mL

Kinetic Study of Oxidation Degradation of Polyphenols in Sour Cherry and Blackberry Extracts During Storage

In this study was to investigate the influence of storage time, light and temperature on stability of polyphenols in sour cherry (Prunus cerasus) and blackberry (Rubus fruticosus), were harvested in western Serbia (Rasinski region). Total phenol content was monitored in the fruit extracts during 23 days stored at 7°C under darkness and 90 days storage at 23°C in oxygen. For analyzed extracts, first-order reaction kinetics was established for the degradation process of polyphenols. The temperature dependence of the polyphenols degradation rate constants was expressed by the temperature coefficients Q10 of the process. It is found that the Q10 values of polyphenols degradation in sour cherry and blackberry extracts were 1.247 and 3.239, respectively

Chemical Composition, Antioxidant, and Antimicrobial Activities of Lichen Umbilicaria cylindrica (L.) Delise (Umbilicariaceae)

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 62.50 μg/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

HPLC analiza i antimikrobna aktivnost biološki aktivnih jedinjenja izolovanih iz lišaja

The aim of this work was the isolation of secondary metabolites from acetone extract of the lichen Hypogymnia physodes and their identification by HPLC analysis.The work was also conceived with the aim to investigate the antimicrobial activity of isolated active components. Fisodic acid, usnic acid and atranorin were isolated from the acetone extract of Hypogymnia physodes.The antimicrobial activity, expressed by the MIC value, were investigated using three standardized bacterial strains and two strains of fungi.The obtained MIC values ranged from 7.5 to 1000 µg/ml, wherein the isolated compounds had the strongest influence on species, Klebsiella pneumoniae and Staphylococcus aureus. Beside above-mentioned compounds,the results of the HPLC analysis showed the presence of other of secondary metabolites, among which were also identified: fumarprotocetraric acid, 3-hydroxyfisodic acid, fisodalic acid, fisodic acid, usnic acid, atranorin and chloratranorin.Cilj ovog rada je izolovanje sekundarnih metabolita iz acetonskog ekstrakta lišaja Hypogymnia physodes i njihova identifikacija primenom HPLC analize.Rad je koncipiran sa ciljem da ispita i antimikrobnu aktivnost izolovanih aktivnih komponenti.Fisodinska kiselina, usninska kiselina i atranorin su izolovana jedinjenja iz acetonskog ekstrakta lišaja Hypogymnia physodes.Antimikrobna aktivnost, izražena preko vrednosti MIC, ispitana je na tri standardizovana bakterijska soja i dva soja gljivica. Dobijene MIC vrednosti su se kretale u opsegu od 7.5 do 1000µg/ml, pri čemu su izolovana jedinjenja najjače dejstvo ispoljila prema vrstama Klebsiella pneumoniae i Staphylococcus aureus. Pored pomenutih jedinjenja, rezultati HPLC analize pokazali su prisustvo više različitih sekundarnih metabolita medju kojima su identifikovani: fumaroprotocetrarinska kiselina, 3-hidroksifisodinska kiselina, fisodalinska kiselina, fisodinska kiselina, usninska kiselina, atranorin i hloratranorin

Phytochemical Analysis, Antioxidant, Antimicrobial, and Cytotoxic Activity of Different Extracts of Xanthoparmelia stenophylla Lichen from Stara Planina, Serbia

The aim of this study was to identify some of the secondary metabolites present in acetonic, methanolic, and hexanic extracts of lichen Xanthoparmelia stenophylla and to examine their antioxidant, antimicrobial, and cytotoxic activity. Compounds of the depsid structure of lecanoric acid, obtusic acid, and atranorin as well as usnic acid with a dibenzofuran structure were identified in the extracts by HPLC. The acetone extract was shown to have the highest total phenolic (167.03 ± 1.12 mg GAE/g) and total flavonoid content (178.84 ± 0.93 mg QE/g) as well as the best antioxidant activity (DPPH IC50 = 81.22 ± 0.54). However, the antimicrobial and antibiofilm tests showed the best activity of hexanic extract, especially against strains of B. cereus, B. subtilis, and S. aureus (MIC < 0.08, and 0.3125 mg/mL, respectively). Additionally, by using the MTT method, the acetonic extract was reported to exhibit a strong cytotoxic effect on the HeLa and HCT-116 cell lines, especially after 72 h (IC50 = 21.17 ± 1.85 and IC50 = 21.48 ± 3.55, respectively). The promising antioxidant, antimicrobial, and cytotoxic effects of Xanthoparmelia stenophylla extracts shown in the current study should be further investigated in vivo and under clinical conditions

Isolation, identification, thermal analysis, DFT calculations and antioxidant activity studies of lichen metabolites norstictic acid and evernic acid

© 2020 National Information and Documentation Center (NIDOC) This manuscript deals with successful trials to isolate two lichen acids (Noristicic and Everinic acids) from natural sources. The isolated compounds were purified, crystallized from suitable solvent, and their melting points were measured. Their structures were identified by elemental analyses, spectroscopic tools (Electronic spectra, FT-IR), Mass and finally using thermal analyses (TG, DTG and DTA). Their thermal fragmentation pathways were compared with mass fragmentation. These fragmentation pathways were compared with the theoretical molecular orbital calculations (DFT- MOCs). The molecular structures of the title compounds in the ground state were optimized by a DFT method using B3LYP functional combined with 6 -311G** (d) basis set. Calculations were carried out using GAUSSIAN 09 suite of programs. In addition, antioxidant activity of norstictic acid and everinic acid were determined. The results showed that both compounds exhibited antioxidant activity, but that the norstictic acid showed several times higher activity than evernic acid. This study refers to successful obtaining of these biologically active acids from natural source s and of wide biomedical applications

Plants from the genus daphne: A review of its traditional uses, phytochemistry, biological and pharmacological activity

© 2017, University of Kragujevac, Faculty of Science. All rights reserved. Plants have an important role in maintaining people’s health and improving the quality of human life. They are an important component of people’s diet, but they are also used in other spheres of human life as a therapeutic resources, ingredients of cosmetic products, paints and others. The Daphne genus belongs to family Th ymeleaceae which includes 44 families with approximately 500 herbal species. The plant species of the genus Daphne are used in the traditional medicine in China and tropical part of Africa for the treatment of various conditions. Previous studies showed significant biological potential of these species as a source of pharmacologically active compounds. This indicates that this genus possess a broad spectrum of biological activity including antimicrobial, antioxidant, analgesic, anti-infl ammatory, cytotoxic, anti-ulcerogenic, abortive, hypocholesterolemic and hemostatic effects. Additionally, Daphne plants are the source of valuable bioactive phytochemicals such as coumarins, flavonoids, lignans, steroids and different classes of terpenes. Different parts of the Daphne plants contain specific bioactive metabolites and can represent a source of new, natural, pharmacologically active compounds, which may potentially be used in pharmaceutical, cosmetic and food industries

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identifed by relative retention time and spectral data. This is the frst time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic signifcance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the frst time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity

<b>Synthesis of C₇-C₁₆-alkyl maltosides in the presence of tin(IV) chloride as a Lewis acid catalyst</b>

The synthesis of C7- to C16-alkyl maltosides in the presence of tin(IV) chloride as Lewis acid catalyst was performed. The characterization of the products and theoretical investigation of the crucial step in the synthesis were carried out. The preparation of the β-maltosides required reaction time of 1 h, and that of the α-maltosides was 72 h. The side products were the α-D-maltosidechloride and 2-hydroxy-β-maltoside, respectively. The PM3 calculation confirmed the formation of the kinetically controlled β-product