salicylates and lecanoric-acid

Lichen extracts containing, among other compounds, depsides such as evernic acid, atranorin, and lecanoric acid possess anti-proliferative effects. We aimed to identify lichen metabolites that are responsible for the observed anti-proliferative effects. We performed cytotoxicity, cell colony, cell cycle and apoptosis assays in various cell lines or primary immune cells. We analyzed several cell cycle proteins and apoptosis-related proteins to gain insights into the underlying mechanism. All depsides reduced the viability of the tested cell lines (HCT-116, HEK293T, HeLa, NIH3T3, RAW246.7) in a cell line-dependent manner with lecanoric acid being the most effective. Atranorin did not influence the cell cycle or colony formation in HCT-116 cells, but induced apoptosis in HCT-116 cells. Evernic acid showed no anti-proliferative effects. Lecanoric acid inhibited cell colony formation already at 0.03 µg/ml in HCT-116 cells and induced a G2 cell cycle block in several cell lines. Moreover, lecanoric acid arrested the cell cycle, presumably in the M phase, since expression of cyclin B1 and phosphorylated histone H3 was upregulated, whereas the inactive cyclin-dependent kinase 1 (CDK1) was reduced in HCT-116 cells. Most importantly, cell death induced by lecanoric acid was more prominent in cancer cells than in primary human immune and endothelial cells. In conclusion, lecanoric acid seems to mediate its anti-proliferative effects via arrest of cells in the M phase. Our data suggest lecanoric acid may be a potential new candidate for anti-cancer therapy, because it has anti-proliferative effects on cancer cell lines, and does not affect primary immune cells.

Topics: Animals; Antineoplastic Agents; Apoptosis; CDC2 Protein Kinase; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Cyclin B1; Endothelial Cells; HEK293 Cells; Histones; Humans; Hydroxybenzoates; Lichens; Mice; Mitosis; NIH 3T3 Cells; Salicylates

This study reports the in vitro anticoagulation activity of acetonic extract (AE) of 42 lichen species and the identification of potential bioavailable anticoagulant compounds from Umbilicaria decussata as a competent anticoagulant lichen species. Lichens' AEs were evaluated for their anticoagulant activity by monitoring activated partial thromboplastin time (APTT) and prothrombin time (PT) assays. A strong, positive correlation was observed between total phenolics concentration (TPC) of species and blood coagulation parameters. U. decussata was the only species with the longest clotting time in both APTT and PT assays. The research was moved forward by performing in vivo assays using rats. The results corroborated the dose-dependent impact of U. decussata's AE on rats' clotting time. Major secondary metabolites of U. decussata and their plasma-related bioavailability were also investigated using LC-ESI-MS/MS. Atranol, orsellinic acid, D-mannitol, lecanoric acid, and evernic acid were detected as possible bioavailable anticoagulants of U. decussata. Our findings suggest that U. decussata might be a potential anticoagulant lichen species that can be used for the prevention or treatment of coagulation-related issues such as cardiovascular diseases (CVDs).

Topics: Anticoagulants; Benzaldehydes; Blood Coagulation; Blood Coagulation Tests; Dose-Response Relationship, Drug; Hydroxybenzoates; Lichens; Mannitol; Plant Extracts; Resorcinols; Salicylates

We performed comparative profiling of four specialized metabolites in the lichen Evernia prunastri, collected at three different geographic locations, California and Maine, USA, and Yoshkar Ola, Mari El, Russia. Among the compounds produced at high concentrations that were identified in all three specimens, evernic acid, usnic acid, lecanoric acid and chloroatranorin, evernic acid was the most abundant. Two depsidones, salazinic acid and physodic acid, were detected in the Yoshkar-Ola collection only. The crystalline structure of evernic acid (2-hydroxy-4-[(2-hydroxy-4-methoxy-6-methylbenzoyl)oxy]-6-methylbenzoate) (hmb) revealed two crystallographically and conformationally distinct hmb anions, along with two monovalent sodium atoms. One hmb moiety contained an exotetradentate binding mode to sodium, whereas the other exhibited an exohexadentate binding mode to sodium. Embedded edge-sharing {Na

Topics: Benzofurans; Hydroxybenzoates; Lichens; Models, Molecular; Salicylates

Claviceps purpurea is a plant pathogenic fungus which is still highly relevant in modern agriculture as it infects grasses such as rye and wheat. The disease caused by the consumption of contaminated grain or flour has been known since the Middle Ages and is termed ergotism. The main cause for the toxicity of this fungus is attributed to the ergot alkaloids. Apart from these alkaloids and the ergochromes known as ergot pigments, the secondary metabolism of C. purpurea is not well investigated. This study demonstrated the function of the polyketide synthase PKS7 in C. purpurea by determining the effect of its overexpression on metabolite profiles. For the first time, the depsides lecanoric acid, ethyl lecanorate, gerfelin, and C10-deoxy gerfelin were discovered as secondary metabolites of C. purpurea. Additionally, to estimate the contribution of isolated secondary metabolites to the toxic effects of C. purpurea, lecanoric acid, ethyl lecanorate, and orsellinic acid were tested on HepG2 and CCF-STTG1 cell lines. This study provides the first report on the function of C. purpurea PKS7 responsible for the production of depsides, among which lecanoric acid and ethyl lecanorate were identified as main secondary metabolites.

Topics: Claviceps; Edible Grain; Ergot Alkaloids; Plant Diseases; Polyketide Synthases; Salicylates; Triticum

Sixteen novel orsellinic esters (

Topics: Animals; Blood Glucose; Depsides; Glycoside Hydrolase Inhibitors; Hyperglycemia; Hypoglycemic Agents; Male; Molecular Docking Simulation; Rats; Rats, Wistar; Resorcinols; Saccharomyces cerevisiae; Salicylates; Structure-Activity Relationship; Sucrose

Thioredoxin reductase (E.C 1.6.4.5.; TrxR) is a widely distributed flavoprotein that catalyzes the NADPH-dependent reduction of thioredoxin (Trx) in many cellular events such as DNA synthesis, DNA repair, angiogenesis, antioxidative defense, and regulating apoptosis. Although TrxR is indispensible in protecting cells against oxidative stress, the overexpression of TrxR is seen in many aggressive tumors. Therefore, targeted inhibition of TrxR has been accepted as a new approach for chemotherapy.. In this study, in vitro inhibition effect of the lichen acids (diffractaic, evernic, lobaric, lecanoric, and vulpinic acid) on mitochondrial TrxR purified from rat lung was investigated.. It was the first time the enzyme was purified from rat lungs by using 2', 5'-ADP Sepharose 4B affinity chromatography. The purity of the enzyme was checked with SDS-PAGE. In vitro inhibition effect of the lichen acids was investigated spectrophotometrically. To emphasize the importance of the obtained data, the commercial anticancer drugs cisplatin and doxorubicin were used as positive controls.. Molecular mass of the enzyme was calculated as approximately 52.4 kDa. The enzyme was purified with a 63.6% yield, 208.3 fold, and 0.5 EU/mg proteins specific activity. The IC50 values of five lichen acids were significantly lower than IC50 values of anticancer drugs.. All of the lichen acids, especially lecanoric and vulpinic acid, exhibited much stronger inhibitory effect on TrxR than the anticancer drugs cisplatin and doxorubicin. These lichen acids have pharmacological potential as effective natural antioxidants, antimicrobials, and anticancer agents.

Topics: Animals; Anisoles; Antineoplastic Agents; Cisplatin; Depsides; Dose-Response Relationship, Drug; Doxorubicin; Enzyme Inhibitors; Furans; Hydroxybenzoates; Lactones; Lichens; Lung; Male; Mitochondria; Molecular Structure; Phenylacetates; Rats; Rats, Sprague-Dawley; Salicylates; Structure-Activity Relationship; Thioredoxin-Disulfide Reductase

Lichen secondary metabolites can function as allelochemicals and affect the development and growth of neighboring bryophytes, fungi, vascular plants, microorganisms, and even other lichens. Lichen overgrowth on bryophytes is frequently observed in nature even though mosses grow faster than lichens, but there is still little information on the interactions between lichens and bryophytes.In the present study, we used extracts from six lichen thalli containing secondary metabolites like usnic acid, protocetraric acid, atranorin, lecanoric acid, nortistic acid, and thamnolic acid. To observe the influence of these metabolites on bryophytes, the moss Physcomitrella patens was cultivated for 5 weeks under laboratory conditions and treated with lichen extracts. Toxicity of natural mixtures of secondary metabolites was tested at three selected doses (0.001, 0.01, and 0.1 %). When the mixture contained substantial amounts of usnic acid, we observed growth inhibition of protonemata and reduced development of gametophores. Significant differences in cell lengths and widths were also noticed. Furthermore, usnic acid had a strong effect on cell division in protonemata suggesting a strong impact on the early stages of bryophyte development by allelochemicals contained in the lichen secondary metabolites.Biological activities of lichen secondary metabolites were confirmed in several studies such as antiviral, antibacterial, antitumor, antiherbivore, antioxidant, antipyretic, and analgetic action or photoprotection. This work aimed to expand the knowledge on allelopathic effects on bryophyte growth.

Topics: Allelopathy; Benzofurans; Bryopsida; Cell Division; Cell Size; Germ Cells, Plant; Heterocyclic Compounds, 3-Ring; Hydroxybenzoates; Lichens; Plant Extracts; Salicylates; Secondary Metabolism

Parkinson's disease (PD) and Amyotrophic lateral sclerosis (ALS), are neurodegenerative disorders characterized by loss of dopaminergic or motor neurons, respectively. Although understanding of the PD and ALS pathogenesis remains incomplete, increasing evidence from human and animal studies has suggested that aberrant GSK3β, oxidative stress and mitochondrial damage are involved in their pathogenesis. Using two different molecular models, treatment with L-BMAA for ALS and rotenone for PD the effect of isolecanoric acid, a natural product isolated from a fungal culture, was evaluated. Pre-treatment with this molecule caused inhibition of GSK3β and CK1, and a decrease in oxidative stress, mitochondrial damage, apoptosis and cell death. Taken together, these results indicated that isolecanoric acid might have a protective effect against the development of these neurodegenerative disorders.

Topics: Amino Acids, Diamino; Apoptosis; Cell Line, Transformed; Cell Survival; Cyanobacteria Toxins; Dose-Response Relationship, Drug; Excitatory Amino Acid Agonists; Flow Cytometry; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Membrane Potential, Mitochondrial; Neuroblastoma; Neuroprotective Agents; Reactive Oxygen Species; Salicylates

Lichens are symbiotic organisms that consist of fungi and photosynthetic symbionts (algae and/or cyanobacteria). Previous studies of their constituents suggested lichens produce many kinds of aromatic secondary metabolites, such as depsides, quinones, and dibenzofurans. In this study, we evaluated the aryl hydrocarbon receptor (AhR) antagonistic activity of 17 lichen substances and demonstrated that atranorin (1) and lecanoric acid (2), isolated from Parmotrema tinctorum Hale, showed an inhibitory effect on luciferase activity increased by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using an XRE-driven pX4TK-Luc reporter gene assay. In addition, CYP1A1 mRNA and protein levels increased by TCDD were also suppressed by 1 and 2. Conversely, neither 1 nor 2 antagonized the suppressive effect of TCDD on interleukin (IL)-1β-induced acute-phase response (APR) gene expression. Thus, we concluded that 1 and 2 were selective AhR modulators that antagonize XRE-dependent activity, but not XRE-independent activity. However, 1 has different characteristics to 2 in that 1 alone showed a suppressive effect on IL-1β-induced APR gene expression in a similar fashion to TCDD.

Topics: Animals; Hep G2 Cells; Humans; Hydroxybenzoates; Lichens; Receptors, Aryl Hydrocarbon; Salicylates; Transfection

To investigate the chemical constituents of the lichen plants Parmelia tinctorum and Parmelia nimandairana collected from Meng Mountain in Shandong province.. Various chromatographic techniques were used to isolate and purify the constituents and their structures were elucidated by means of spectral evidence and physiochemical properties.. Four compounds were isolated from Parmelia tinctorum and identified as: lecanoric acid (I), evernic acid (II), ethyl orsellinate (III) and 3,5-dihydroxytoluene (IV). Two compounds were isolated from Parmelia nimandairana and identified as: usnic acid (V) and salazinic acid (VI).. Compounds V and VI are isolated from Parmelia nimandairana for the first time.

Topics: Benzofurans; China; Chromatography, High Pressure Liquid; Hydroxybenzoates; Lactones; Lichens; Molecular Structure; Resorcinols; Salicylates; Solvents

Sequence analyses of fungal genomes have revealed that the potential of fungi to produce secondary metabolites is greatly underestimated. In fact, most gene clusters coding for the biosynthesis of antibiotics, toxins, or pigments are silent under standard laboratory conditions. Hence, it is one of the major challenges in microbiology to uncover the mechanisms required for pathway activation. Recently, we discovered that intimate physical interaction of the important model fungus Aspergillus nidulans with the soil-dwelling bacterium Streptomyces rapamycinicus specifically activated silent fungal secondary metabolism genes, resulting in the production of the archetypal polyketide orsellinic acid and its derivatives. Here, we report that the streptomycete triggers modification of fungal histones. Deletion analysis of 36 of 40 acetyltransferases, including histone acetyltransferases (HATs) of A. nidulans, demonstrated that the Saga/Ada complex containing the HAT GcnE and the AdaB protein is required for induction of the orsellinic acid gene cluster by the bacterium. We also showed that Saga/Ada plays a major role for specific induction of other biosynthesis gene clusters, such as sterigmatocystin, terrequinone, and penicillin. Chromatin immunoprecipitation showed that the Saga/Ada-dependent increase of histone 3 acetylation at lysine 9 and 14 occurs during interaction of fungus and bacterium. Furthermore, the production of secondary metabolites in A. nidulans is accompanied by a global increase in H3K14 acetylation. Increased H3K9 acetylation, however, was only found within gene clusters. This report provides previously undescribed evidence of Saga/Ada dependent histone acetylation triggered by prokaryotes.

Topics: Acetylation; Aspergillus nidulans; Biocatalysis; Biological Products; Fungal Proteins; Gene Deletion; Gene Expression Regulation, Fungal; Genes, Fungal; Histone Acetyltransferases; Histones; Models, Biological; Multigene Family; Promoter Regions, Genetic; Resorcinols; Salicylates; Sterigmatocystin; Streptomyces

Antioxidant activity of several classes of lichen metabolites were assessed in the in vitro superoxide radical (SOR), nitric oxide radical and 2,2-diphenyl-1-picrylhydrazil radical scavenging assays. The despsides sekikaic acid and lecanoric acid showed promising antioxidant activity in SOR assay with IC₅₀ values of 82.0 ± 0.3 µmol and 91.5 ± 2.1 µmol, respectively, while the depsidone lobaric acid exhibited an IC₅₀ value of 97.9 ± 1.6 µmol, all relative to the standard, propyl gallate (IC₅₀ = 106.0 ± 1.7 µmol). One of the most abundant mononuclear phenolic compounds, methyl-β-orcinol carboxylate was found to be a potent NO scavenger (IC₅₀ = 84.7 ± 0.1 µmol), compared to the standard rutin (IC₅₀ = 86.8 ± 1.9 µmol).

Topics: Antioxidants; Biphenyl Compounds; Chemical Fractionation; Complex Mixtures; Depsides; Enzyme-Linked Immunosorbent Assay; Free Radical Scavengers; In Vitro Techniques; Inhibitory Concentration 50; Lactones; Lichens; Molecular Structure; Nitric Oxide; Picrates; Salicylates; Species Specificity; Superoxides

Lecanoric acid (1), orsellinic acid methyl ester (2), orcinol (3), and usnic acid (4) were isolated from the lichen Parmelia subrudecta, collected on Palma of the Canary Islands, Spain. Compounds 1, 2, 3, and 4 were purified by solvent extraction, silica gel column chromatography, and preparative high-performance liquid chromatography (HPLC) consecutively. The structures of the four compounds were elucidated by one- and two-dimensional nuclear magnetic resonance (NMR) experiments and mass spectrometric investigations. These compounds showed activity against important gram-positive and gram-negative pathogens like mycobacteria and multiresistant staphylococci. This activity is combined with antiproliferative activity and cytotoxicity.

Topics: Anti-Infective Agents; Antineoplastic Agents; Bacteria; Bacterial Infections; Benzofurans; Cell Line, Tumor; Cell Proliferation; Humans; Lichens; Magnetic Resonance Spectroscopy; Molecular Structure; Neoplasms; Resorcinols; Salicylates; Spectrometry, Mass, Electrospray Ionization

The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory natural products, the MeOH extract of the dried sample of the Antarctic lichen Umbilicaria antarctica was found to exhibit significant inhibitory effect, and the bioassay-guided fractionation and purification afforded three related lichen metabolites 1-3. Compounds 1-3 were identified as gyrophoric acid (1), lecanoric acid (2), and methyl orsellinate (3) mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 3.6 +/- 0.04 microM, 31 +/- 2.7 microM, and 277 +/- 8.6 microM, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compound 1 suggested that the compound inhibited PTP1B activity in a non-competitive manner.

Topics: Antarctic Regions; Benzoates; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Inhibitors; Lichens; Magnetic Resonance Spectroscopy; Mass Spectrometry; Plant Extracts; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Resorcinols; Salicylates

Fungi produce numerous low molecular weight molecules endowed with a multitude of biological activities. However, mining the full-genome sequences of fungi indicates that their potential to produce secondary metabolites is greatly underestimated. Because most of the biosynthesis gene clusters are silent under laboratory conditions, one of the major challenges is to understand the physiological conditions under which these genes are activated. Thus, we cocultivated the important model fungus Aspergillus nidulans with a collection of 58 soil-dwelling actinomycetes. By microarray analyses of both Aspergillus secondary metabolism and full-genome arrays and Northern blot and quantitative RT-PCR analyses, we demonstrate at the molecular level that a distinct fungal-bacterial interaction leads to the specific activation of fungal secondary metabolism genes. Most surprisingly, dialysis experiments and electron microscopy indicated that an intimate physical interaction of the bacterial and fungal mycelia is required to elicit the specific response. Gene knockout experiments provided evidence that one induced gene cluster codes for the long-sought after polyketide synthase (PKS) required for the biosynthesis of the archetypal polyketide orsellinic acid, the typical lichen metabolite lecanoric acid, and the cathepsin K inhibitors F-9775A and F-9775B. A phylogenetic analysis demonstrates that orthologs of this PKS are widespread in nature in all major fungal groups, including mycobionts of lichens. These results provide evidence of specific interaction among microorganisms belonging to different domains and support the hypothesis that not only diffusible signals but intimate physical interactions contribute to the communication among microorganisms and induction of otherwise silent biosynthesis genes.

Topics: Actinobacteria; Aspergillus nidulans; Blotting, Northern; Chromatography, High Pressure Liquid; Ecosystem; Fungal Proteins; Gene Expression Profiling; Gene Expression Regulation, Fungal; Genome, Fungal; Macrolides; Microscopy, Electron, Scanning; Molecular Structure; Mutation; Mycelium; Oligonucleotide Array Sequence Analysis; Phylogeny; Polyketide Synthases; Reverse Transcriptase Polymerase Chain Reaction; Salicylates; Zearalenone

To study the chemical constituents from the fruit bodies of Umbilicaria esculenta.. Five compounds were isolated from the ethanolic extract of this plant by all kinds of column chormatography, and structures were identified by spectroscopic analysis.. Five compounds were identified as ethyl orsellinate, orsellinic acid, orcinol, lecanoric acid and lecanorin.. Ethyl orsellinate, orsellinic acid, orcinol and lecanorin were isolated from this plant for the first time.

Topics: Lichens; Resorcinols; Salicylates

Lecanoric acid analogues containing benzanilide structure inhibited histidine decarboxylase and arachidonic acid release from the cell membrane phospholipids induced by a tumour promoter, 12-O-tetradecanoylphorbol-13-acetate. But they did not inhibit cellular binding of phorbol-12,13-dibutylate. Lecanoric acid analogues also inhibited prostaglandin synthetase and delayed-type hypersensitivity responses against sheep red blood cells in mice. Thus, lecanoric acid analogues antagonized several enzymic and cellular effects of the tumour promoter.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Benzamides; Carboxy-Lyases; Cell Membrane; Cells, Cultured; Embryo, Mammalian; Female; Histidine Decarboxylase; Kinetics; Membrane Lipids; Mice; Phorbols; Phospholipids; Pregnancy; Rats; Salicylates; Structure-Activity Relationship; Tetradecanoylphorbol Acetate