Eugênia C. Pereira

Pigment analysis of sun and shade populations of Cladonia verticillaris

Abstract The natural occurrence of the lichen Cladonia verticillaris as sunny and shaded populations implies changes in the pigment content. Shade specimens contain more chlorophyll a and b as well as more α- and β-carotene than those found in unshaded lichens. However, lichens growing in sunny locations contain more methyl β-orcinol carboxylate, orcinol and fumarprotocetraric acid than those found in lichens growing under low light intensities. No structural differences in the chloroplasts of the two species bave been detected.

Cladia aggregata (lichen) from Brazilian northeast: chemical characterization and antimicrobial activity

A composicao quimica e a atividade antimicrobiana da Cladia aggregata (Sw.) Nyl. foram avaliadas. O acido barbatico, um depsideo obtido da C. aggregata, foi espectroscopicamente analisado e testado, bem como o extrato orgânico. o extrato e a substância purificada foram testadas contra 4 linhagens de Staphylococcus aureus multi resistentes. A estrutura do acido barbatico foi confirmada atraves de ensaios de CCD, CLAE, IV, RMN (1H;13C), UV e analise elementar (r). O biocromatograma mostrou a acao deste composto junto com outras substâncias contidas no extrato orgânico, sugerindo a acao sinergica, a CMI do acido barbatico mostrou o mesmo nivel de inibicao de outras substâncias liquenicas.

Usnic acid-loaded nanocapsules: an evaluation of cytotoxicity

The aim of the present study is the design of nanocapsules containing usnic acid (UA-NC) and the evaluation of their physicochemical properties, in vitro kinetic profile and cytotoxic effect on human lung carcinoma cells. The usnic acid was encapsulated into nanocapsules prepared with a copolymer of lactic and glycolic acid using an interfacial deposition of a preformed polymer on oil-in-water emulsion. The cytotoxicity of nanocapsules was evaluated by the MTT method. UA-NC were obtained with a mean diameter of 324 ± 88 nm. An encapsulation ratio of 99.4 ± 0.16% was attained at an usnic acid concentration of 1 mg/ml. An usnic acid release of 78.3% from nanocapsules within 48 h was achieved. Concentrations required to inhibit 50% of cell growth were 10.0 and 11.5 μg/ml for free and encapsulated usnic acid, respectively. In conclusion, usnic acid was, for the first time, efficiently encapsulated into PLGA nanocapsules, providing a suitable dosage form for introducing usnic acid in in vivo studies, the use of which has been limited by its poor solubility and toxic properties.

Influência de poluentes atmosféricos em Belo Jardim (PE) utilizando Cladonia verticillaris (líquen) como biomonitor

Cladonia verticillaris used in this study was collected in the cerrado vegetation of Saloa (PE, Brazil) and transplanted in plastic containers on soil from the collection place to Belo Jardim (PE) that possesses lead smelters and battery industries. The experiments were disposed at eleven different places for evaluating the dispersion of pollutants and their effects on the biomonitor. The exposed lichens were collected over eight months and submitted to thin layer and high performance liquid chromatographies, and scanning electron microscopy. C. verticillaris placed in the vicinity of the emission sources demonstrated alteration in its metabolism, decreasing the production of its major compound, fumarprotocetraric acid, and deterioration of its external and internal surfaces.

Requirements to produce fumarprotocetraric acid using alginate-immobilized cells of Cladonia verticillaris

The biosynthesis of the depsidone, fumarprotocetraric acid, a compound previously considered to be only produced by lichens, has been confirmed by using alginate-immobilized cells of Cladonia verticillaris. Immobilized cells only produce the depsidone when they are supplemented with FMN and acetate. This implies that fumaric acid which esterifies an alcohol function in the C3 of a depsidone precursor is added through a reducing, flavin-dependent, coupling reaction that uses the pool of succinyl-CoA from the fungal partner.

Atividade antimicrobiana de derivados fenólicos do líquen Ramalina sorediosa (B. de Lesd.) Laundron

The antimicrobian activity of crude extracts from Ramalina sorediosa was detected by the diffusion disc-paper method. Two phenolic compounds from the lichen considered active were detected by using biochromathograhyc technique. Two of those compounds were identified through thin layer chromatographic technique (TLC) as been usnic acid and the second one, wich is present in higher concentration when compared with the other substances, was the homosekikaik acid. The TLC and high-pressure liquid chromatography (HPLC) assays still detected the salazanic acid presence. The obtained data make it possible to attribute the antibiotic activity of this species to a synergic association of those two substances.

Produção de compostos fenólicos a partir de células imobilizadas do líquen Parmotrema andinum (Müll. Arg.) Hale e avaliação de atividade antimicrobiana

A utilizacao de metabolitos secundarios obtidos de liquens, na industria farmaceutica, de cosmetico, textil e de alimentos deve ser criteriosa, visto que a extracao e isolamento desses metabolitos requerem uma grande quantidade de biomassa dificilmente renovavel, devido ao crescimento lento do liquen. Atualmente, e possivel obter substâncias liquenicas tanto por cultivo de tecidos, como por imobilizacoes celulares e enzimaticas, a partir do talo in natura, utilizando pequena quantidade de material liquenico. Portanto, este trabalho objetiva investigar a producao de compostos fenolicos a partir de celulas imobilizadas de Parmotrema andinum (Mull. Arg.) Hale utilizando acetato de sodio como precursor da biossintese dos fenois. Ensaios de atividade antimicrobiana com extratos orgânicos do talo in natura, eluatos celulares e do acido lecanorico isolado de P. andinum Hale demonstraram acao contra bacterias Gram-positivas. Atraves de testes biocromatograficos foi possivel associar a atividade antibacteriana ao acido lecanorico e uma substância nao identificada presente na especie. As substâncias produzidas atraves de imobilizacao celular nao exibiram acao inibitoria frente os microrganismos testados.

Laboratory assessment of divaricatic acid against Biomphalaria glabrata and Schistosoma mansoni cercariae

In this study, the molluscicidal and antiparasitic activities of divaricatic acid was evaluated, targeting the mollusc Biomphalaria glabrata and cercariae of the helminth Schistosoma mansoni. In addition, the environmental toxicity of divaricatic acid was assessed by bioassay using the microcrustacean Artemia salina. Divaricatic acid showed high toxicity against both adult snails (5μg/mL) and embryos (20μg/mL after 6h of exposure). Similar activity was observed in Schistosoma mansoni cercariae after only a short exposure time (10μg/mL after 30min of exposure). The divaricatic acid did not show toxicity in the acute test using Artemia salina at concentrations equal to or below 200μg/mL. The divaricatic acid proved to be a promising substance for the elimination of the snail Biomphalaria glabrata, an intermediate host of schistosomiasis, as well as the cercariae of the pathogen, while being non-toxic to the Artemia salina at the same concentrations. This is the first experimental observation of the molluscicidal and cercaricide activity of divaricatic acid.

Chemotaxonomic Fingerprinting of Chilean Lichens Through Maldi and Electrospray Ionization Mass Spectrometry

The aim of this work was to study a fast, new, sensitive, and simple method for the chemotaxonomic classification of Chilean lichens (Teloschistes chrysophthalmus, Ramalina farinacea, Usnea pusilla, Ramalina chilensis and Stereocaulon ramulosum) using MALDI-TOF-MS and UPLC-ESI(-)-MS data. Lichens soluble proteins fingerprints were acquired by MALDI-TOF-MS and they were analyzed by chemometric (PCA). Lichens organic extracts fingerprints were obtained by UPLC-ESI(-)-MS. MALDI-TOF-MS associated with chemometric analysis was used to detect new m/z patterns of soluble proteins that were compared with Protein Data Bank of UnitPro. These data also permitted the satisfactory distinction among the families and species. UPLC-ESI(-)-MS fingerprints analyses of the organic extracts showed the presence of five major lichen compounds (atranorin, parietin, teloschistin, ramalinolic and usnic acids). In contrast to other techniques, MALDI-TOF-MS associated with chemometric analysis and UPLC-ESI(-)-MS provided a new, fast and sensitive method for chemotaxonomic characterization of lichens.

Produção de metabólitos bioativos pelo líquen Cladonia substellata Vainio

ABSTRACT – (Production of bioactive metabolites from lichen Cladonia substellata Vainio). This work purposed to make a comparisonbetween antimicrobial activity of crude extracts from Cladonia substellata , collected at Minas Gerais and Para States, Brazil, using thediffusion solid medium methods. Ether, chloroform, and acetone extracts, at 1 mg/mL, 0.1 mg/mL, and 0.01 mg/mL, were tested againsthuman pathogens and phytopathogens. The extracts were submitted to thin layer chromatography and their active p rinciplesattributed by biochromatography. The results demonstrated that the seven fungi species tested were no sensitive to extracts from C. substellata from Para. On the other hand, four of these microorganisms were inhibited by C. substellata extracts from Minas Gerais.All extracts were active to the same bacteria species, but samples from Minas Gerais showed the highest activity. Among the inh ibitedbacteria Staphylococcus aureus was the less sensitive, with an opposite behavior to phytopathogen ones, that showed the highestsensitivity. Chromatographic assays revealed the presence of usnic acid in all extracts, thus in the most content in Para samples. Thebiochromatograms reveals usnic acid as active principle of the species, and a synergic action to norstictic acid found in Minas Geraissamples, what justify its highest activity.