RESUMEN

In this study, we accessed culturable fungal assemblages present in the sediments of three lakes potentially impacted anthropogenically in the Fildes Peninsula, King George Island, Antarctica and identified 63 taxa. Cladosporium sp. 2, Pseudeurotium hygrophilum, and Pseudogymnoascus verrucosus were recovered from the sampled sediments of all lakes. High concentrations of metals and the lowest fungal diversity indices were detected in the sediments of the Central Lake, which can be influenced by human activities due to their proximity to research stations to those of the other two lakes, which were far from the Antarctic stations. At least one type of biological activity was demonstrated by 40 fungal extracts. Among these, P. hygrophilum, P. verrucosus, Penicillium glabrum, and Penicillium solitum demonstrated strong trypanocidal, herbicidal, and antifungal activities. Our results suggest that an increase of the anthropogenic activities in the region might have affected the microbial diversity and composition. In addition, the fungal diversity in these lakes may be a useful model to study the effect of anthropogenic activities in Antarctica. We isolated a diverse group of fungal taxa from Antarctic lake sediments, which have the potential to produce novel compounds for the both the medical and agriculture sectors.

Asunto(s)

Bioprospección , Regiones Antárticas , Ascomicetos , Sedimentos Geológicos , Humanos , Islas , Lagos

RESUMEN

We recovered 195 fungal isolates from the sediments of different lakes in the Antarctic Peninsula, which were screened to detect bioactive compounds. Forty-two taxa belonging to the phyla Ascomycota, Basidiomycota, and Mortierellomycota were identified. Thelebolus globosus, Antarctomyces psychrotrophicus, Pseudogymnoascus verrucosus, Vishniacozyma victoriae, and Phenoliferia sp. were found to be the most prevalent. The fungal assemblages showed high diversity and richness, but low dominance values. However, the diversity indices and fungal distribution ranged according to the different lake sediments. Sixty fungal extracts displayed at least one biological activity against the evaluated targets. Among them, Pseudogymnoascus destructans showed selective trypanocidal activity, Cladosporium sp. 1 and Trichoderma polysporum showed antifungal activity, and Pseudogymnoascus appendiculatus and Helotiales sp. showed high herbicidal activity. We detected a rich and diverse fungal community composed of cold cosmopolitan and psychrophilic endemic taxa recognized as decomposers, symbiotics, pathogens, and potential new species, in the sediments of Antarctic lakes. The dynamics and balance of this fungal community represents an interesting aquatic web model for further ecological and evolutionary studies under extreme conditions and potential climate changes in the regions. In addition, we detected fungal taxa and isolates able to produce bioactive compounds that may represent the source of prototype molecules for applications in medicine and agriculture.

Asunto(s)

Hongos/aislamiento & purificación , Hongos/metabolismo , Sedimentos Geológicos/microbiología , Lagos/microbiología , Micobioma , Animales , Regiones Antárticas , Antifúngicos/análisis , Antifúngicos/farmacología , Antiprotozoarios/análisis , Antiprotozoarios/farmacología , Antivirales/análisis , Antivirales/farmacología , Ascomicetos/clasificación , Ascomicetos/crecimiento & desarrollo , Ascomicetos/aislamiento & purificación , Ascomicetos/metabolismo , Basidiomycota/clasificación , Basidiomycota/crecimiento & desarrollo , Basidiomycota/aislamiento & purificación , Basidiomycota/metabolismo , Biodiversidad , Bioprospección , Línea Celular , Hongos/clasificación , Hongos/crecimiento & desarrollo , Herbicidas/análisis , Herbicidas/farmacología

RESUMEN

We accessed the culturable mycobiota present in marine sediments at different depths in Antarctica Ocean. Acremonium fusidioides, Penicillium allii-sativi, Penicillium chrysogenum, Penicillium palitans, Penicillium solitum, and Pseudogymnoascus verrucosus were identified. Penicillium allii-sativi was the dominant species. At least one isolate of each species was capable to present antifungal, trypanocidal, leishmanicidal, antimalarial, nematocidal, or herbicidal activities. Penicillium produced extracts with strong trypanocidal and antimalarial activities, and the extracts of P. solitum and P. chrysogenum demonstrated strong antimalarial activities. Acremonium fusidioides and P. verrucosus displayed strong selective herbicidal properties. The 1H NMR signals for extracts of A. fusidioides, P. chrysogenum, and P. solitum indicated the presence of highly functionalized secondary metabolites, which may be responsible for the biological activities detected. In the deep marine Antarctic sediments, we detected fungal assemblages in which the Penicillium species were found to be dominant and demonstrated capabilities to survive and/or colonise that poly-extreme habitat. Penicillium being a polyextremophile Antarctic species, exhibited strong biological activities and the presence of aromatic compounds in its extracts may indicate that they are wild ancient strains with high genetic and biochemical potentials that enable them to produce bioactive compounds which can be researched in further studies and used in the chemotherapy of neglected tropical diseases as well as in agriculture.

Asunto(s)

Ascomicetos , Bioprospección , Regiones Antárticas , Antifúngicos , Hongos , Penicillium

RESUMEN

We describe the potent effect of myriadenolide (Myr), a naturally occurring labdane diterpene, in promoting the production of eosinophils in cultured bone-marrow from several inbred mouse strains. This enhancing effect is lineage-selective and requires the eosinophil growth factors, Interleukin(IL)-5 or GM-CSF. Myr acts over a very low concentration range (10-10-10-14 M), if added at the beginning of the cell cultivation. Its enhancing effect increases between 24 h and 10 days of culture. We used both pharmacological and genetical tools to analyze its mechanism of action. Several lines of evidence show that the enhancing effect of Myr requires functional integrity of the 5-lipoxygenase (5-LO) pathway, and of CysLT1 receptors, which transduce the effects of cysteinyl-leukotrienes generated through this pathway. Myr also protects developing eosinophils from apoptosis induced by exogenous prostaglandin E2 (PGE2), but not by NO, indicating that it acts upstream of NO in the PGE2-initiated proapoptotic pathway which requires iNOS and CD95. Exposure to NO concentrations insufficient to induce apoptosis abolished the ability of eosinophils to respond to Myr, suggesting the involvement of a NO-sensitive cellular target. Myr has potential as a chemically defined research tool, which can be used to generate large numbers of eosinophils, thereby overcoming current limitations in the biochemical and molecular biological study of murine eosinophils, which has so far depended on complex, labor-intensive and long-term culture protocols for in vitro expansion. SUMMARY: Potent enhancing effects of Myr on eosinophil production in bone marrow stimulated by GM-CSF and IL-5 are mediated by the 5-LO pathway.

Asunto(s)

Cisteína/metabolismo , Diterpenos/farmacología , Eosinófilos/efectos de los fármacos , Leucotrienos/metabolismo , Animales , Araquidonato 5-Lipooxigenasa/metabolismo , Médula Ósea/efectos de los fármacos , Células Cultivadas , Dinoprostona/farmacología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Interleucina-5/farmacología , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Donantes de Óxido Nítrico/farmacología , Receptores de Leucotrienos/metabolismo , Transducción de Señal/efectos de los fármacos

RESUMEN

The endophytic fungus Mycosphaerella sp. (UFMGCB2032) was isolated from the healthy leaves of Eugenia bimarginata, a plant from the Brazilian savanna. Two novel usnic acid derivatives, mycousfuranine (1) and mycousnicdiol (2), were isolated from the ethyl acetate extract, and their structure was elucidated by NMR and MS analyses. Compounds 1 and 2 exhibited moderate antifungal activities against Cryptococcus neoformans and Cryptococcus gattii, each with minimum inhibitory concentration values of 50.0 µg/mL and 250.0 µg/mL, respectively.

Asunto(s)

Antifúngicos/farmacología , Ascomicetos/química , Benzofuranos/farmacología , Antifúngicos/análisis , Ascomicetos/patogenicidad , Benzofuranos/análisis , Cryptococcus/efectos de los fármacos , Eugenia/microbiología

RESUMEN

Molecular biology techniques were used to identify 218 fungi from soil samples collected from four islands of Antarctica. These consisted of 22 taxa of 15 different genera belonging to the Zygomycota, Ascomycota, and Basidiomycota. Mortierella, Antarctomyces, Pseudogymnoascus, and Penicillium were the most frequently isolated genera and Penicillium tardochrysogenum, Penicillium verrucosus, Goffeauzyma gilvescens, and Mortierella sp. 2 the most abundant taxa. All fungal isolates were cultivated using solid-state fermentation to obtain their crude extracts. Pseudogymnoascus destructans, Mortierella parvispora, and Penicillium chrysogenum displayed antiparasitic activities, whilst extracts of P. destructans, Mortierella amoeboidea, Mortierella sp. 3, and P. tardochrysogenum showed herbicidal activities. Reported as pathogenic for bats, different isolates of P. destructans exhibited trypanocidal activities and herbicidal activity, and may be a source of bioactive molecules to be considered for chemotherapy against neglected tropical diseases. The abundant presence of P. destructans in soils of the four islands gives evidence supporting that soils in the Antarctic Peninsula constitute a natural source of strains of this genus, including some P. destructans strains that are phylogenetically close to those that infect bats in North America and Europe/Palearctic Asia.

Asunto(s)

Antiprotozoarios/farmacología , Hongos/genética , Herbicidas/farmacología , Microbiota , Filogenia , Microbiología del Suelo , Allium/efectos de los fármacos , Regiones Antárticas , Antivirales/farmacología , Virus del Dengue/efectos de los fármacos , Hongos/clasificación , Hongos/aislamiento & purificación , Hongos/metabolismo , Lactuca/efectos de los fármacos , Trypanosoma cruzi/efectos de los fármacos , Virus Zika/efectos de los fármacos

RESUMEN

The bioassay-guided fractionation of the ethyl acetate extract of the fungus Cochliobolus sp. highlighted leishmanicidal activity and allowed for anhydrocochlioquinone A (ANDC-A) isolation. MS, 1D and 2D NMR spectra of this compound were in agreement with those published in the literature. ANDC-A exhibited leishmanicidal activity with EC 50 value of 22.4 microgram/mL (44 mu M) and, when submitted to the microdilution assay against Gram-ositive and Gram-negative bacteria, showed a minimal inhibitory concentration against Staphylococcus aureus ATCC 25295 of 128 microgram/mL (248.7 mu M). It was also active against five human cancer cell lines, showing IC50 values from 5.4 to 20.3 mu M. ANDC-A demonstrated a differential selectivity for HL-60 (SI 5.5) and THP-1 (SI 4.3) cell lines in comparison with Vero cells and was more selective than cisplatin and doxorubicin against MCF-7 cell line in comparison with human peripheral blood mononuclear cells. ANDC-A was able to eradicate clonogenic tumour cells at concentrations of 20 and 50 mu M and induced apoptosis in all tumour cell lines at 20 mu M. These results suggest that ANDC-A might be used as a biochemical tool in the study of tumour cells biochemistry as well as an anticancer agent with durable effects on tumours.

Asunto(s)

Antibacterianos/farmacología , Antineoplásicos/farmacología , Antiprotozoarios/farmacología , Ascomicetos/química , Benzoquinonas/farmacología , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Antiprotozoarios/química , Antiprotozoarios/aislamiento & purificación , Ascomicetos/metabolismo , Benzoquinonas/química , Benzoquinonas/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Células HCT116 , Células HL-60 , Humanos , Células Jurkat , Klebsiella oxytoca/efectos de los fármacos , Klebsiella oxytoca/crecimiento & desarrollo , Leishmania mexicana/efectos de los fármacos , Leishmania mexicana/crecimiento & desarrollo , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/crecimiento & desarrollo , Células MCF-7 , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/crecimiento & desarrollo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Células THP-1 , Células Vero

RESUMEN

This study assessed the diversity of cultivable rock-associated fungi from Atacama Desert. A total of 81 fungal isolates obtained were identified as 29 Ascomycota taxa by sequencing different regions of DNA. Cladosporium halotolerans, Penicillium chrysogenum and Penicillium cf. citrinum were the most frequent species, which occur at least in four different altitudes. The diversity and similarity indices ranged in the fungal communities across the latitudinal gradient. The Fisher-α index displayed the higher values for the fungal communities obtained from the siltstone and fine matrix of pyroclastic rocks with finer grain size, which are more degraded. A total of 23 fungal extracts displayed activity against the different targets screened. The extract of P. chrysogenum afforded the compounds α-linolenic acid and ergosterol endoperoxide, which were active against Cryptococcus neoformans and methicillin-resistance Staphylococcus aureus respectively. Our study represents the first report of a new habitat of fungi associated with rocks of the Atacama Desert and indicated the presence of interesting fungal community, including species related with saprobes, parasite/pathogen and mycotoxigenic taxa. The geological characteristics of the rocks, associated with the presence of rich resident/resilient fungal communities suggests that the rocks may provide a favourable microenvironment fungal colonization, survival and dispersal in extreme conditions.

Asunto(s)

Ascomicetos/metabolismo , Cladosporium/metabolismo , Cryptococcus neoformans/efectos de los fármacos , Sedimentos Geológicos/microbiología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Penicillium/metabolismo , Ascomicetos/clasificación , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Chile , Cladosporium/clasificación , Cladosporium/genética , Cladosporium/aislamiento & purificación , Clima Desértico , Ecología , Ecosistema , Datos de Secuencia Molecular , Penicillium/clasificación , Penicillium/genética , Penicillium/aislamiento & purificación

RESUMEN

Endophytic fungi represent ubiquitous microbial organisms able to live in the tissues of different plants around the world and represent a prolific source of bioactive metabolites. In the present study, the endophytic fungus Aspergillus calidoustus was isolated from the medicinal plant Acanthospermum australe (Asteraceae), and identified using molecular, physiological and morphological methods. A methylene chloride crude extract of A. calidoustus has been produced and subjected to antifungal bioassay-directed fractionation which resulted in the isolation of the two bioactive compounds: ophiobolin K and 6-epi-ophiobolin K. These pure compounds displayed antifungal activity against fungal plant pathogens, protozoal activity against Trypanosoma cruzi, and cytotoxic activity against human tumoral cell lines. The results show that A. calidoustus was able to produce the antifungal and cytotoxic metabolites ophiobolin K and 6-epi-ophiobolin K, which may help the fungus to colonise and occupy the substratum as well as survive in natural environments.

Asunto(s)

Antifúngicos/química , Antimaláricos/química , Antineoplásicos/química , Aspergillus/química , Sesterterpenos/química , Antifúngicos/aislamiento & purificación , Antimaláricos/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Asteraceae/microbiología , Línea Celular Tumoral , Humanos

RESUMEN

Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 µg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 µg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 µg/mL), Candida albicans and Candida tropicalis (MIC 64-128 µg/mL). Fourteen extracts at a concentration of 20 µg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 µg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 µg/mL (2.43 µM) in a T. cruzi cellular culture assay.

Asunto(s)

Caesalpinia/microbiología , Depsipéptidos/farmacología , Endófitos/aislamiento & purificación , Fusarium/aislamiento & purificación , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Candida albicans/efectos de los fármacos , Línea Celular Tumoral/efectos de los fármacos , Fraccionamiento Químico , Mezclas Complejas , Cartilla de ADN , Depsipéptidos/aislamiento & purificación , Endófitos/clasificación , Enterobacteriaceae/efectos de los fármacos , Fusarium/metabolismo , Bacilos Grampositivos Formadores de Endosporas/efectos de los fármacos , Humanos , Leishmania/efectos de los fármacos , Leucocitos Mononucleares/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos , Tripanocidas/aislamiento & purificación

RESUMEN

We surveyed the diversity and capability of producing bioactive compounds from a cultivable fungal community isolated from oligotrophic soil of continental Antarctica. A total of 115 fungal isolates were obtained and identified in 11 taxa of Aspergillus, Debaryomyces, Cladosporium, Pseudogymnoascus, Penicillium and Hypocreales. The fungal community showed low diversity and richness, and high dominance indices. The extracts of Aspergillus sydowii, Penicillium allii-sativi, Penicillium brevicompactum, Penicillium chrysogenum and Penicillium rubens possess antiviral, antibacterial, antifungal, antitumoral, herbicidal and antiprotozoal activities. Bioactive extracts were examined using (1)H NMR spectroscopy and detected the presence of secondary metabolites with chemical shifts. Our results show that the fungi present in cold-oligotrophic soil from Antarctica included few dominant species, which may have important implications for understanding eukaryotic survival in cold-arid oligotrophic soils. We hypothesize that detailed further investigations may provide a greater understanding of the evolution of Antarctic fungi and their relationships with other organisms described in that region. Additionally, different wild pristine bioactive fungal isolates found in continental Antarctic soil may represent a unique source to discover prototype molecules for use in drug and biopesticide discovery studies.

Asunto(s)

Bioprospección , Frío Extremo , Hongos/aislamiento & purificación , Microbiota , Microbiología del Suelo , Aedes/efectos de los fármacos , Animales , Regiones Antárticas , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/toxicidad , Productos Biológicos/aislamiento & purificación , Productos Biológicos/toxicidad , Citotoxinas/aislamiento & purificación , Citotoxinas/toxicidad , Hongos/química , Hongos/clasificación , Humanos , Insecticidas/aislamiento & purificación , Insecticidas/toxicidad , Lactuca/efectos de los fármacos , Células MCF-7

RESUMEN

We surveyed diversity patterns and engaged in bioprospecting for bioactive compounds of fungi associated with the endemic macroalgae, Monostroma hariotii and Pyropia endiviifolia, in Antarctica. A total of 239 fungal isolates were obtained, which were identified to represent 48 taxa and 18 genera using molecular methods. The fungal communities consisted of endemic, indigenous and cold-adapted cosmopolitan taxa, which displayed high diversity and richness, but low dominance indices. The extracts of endemic and cold-adapted fungi displayed biological activities and may represent sources of promising prototype molecules to develop drugs. Our results suggest that macroalgae along the marine Antarctic Peninsula provide additional niches where fungal taxa can survive and coexist with their host in the extreme conditions. We hypothesise that the dynamics of richness and dominance among endemic, indigenous and cold-adapted cosmopolitan fungal taxa might be used to understand and model the influence of climate change on the maritime Antarctic mycota.

Asunto(s)

Biodiversidad , Chlorophyta/microbiología , Hongos/fisiología , Rhodophyta/microbiología , Regiones Antárticas , ADN Intergénico/genética , Hongos/genética , Hongos/aislamiento & purificación , Hongos/metabolismo , Geografía , Datos de Secuencia Molecular , Análisis de Secuencia de ADN

RESUMEN

Annona cornifolia A. St. -Hil. is a small annual perennial tree found in the Brazilian savannah; their green fruit is popularly used in the treatment of ulcers. The acetogenins isolated from the seeds of Annona cornifolia previously showed to possess antioxidant activity. In continuation of our investigations on the biological activities of acetogenins, four binary mixtures and ten pure adjacent bis-tetrahydrofuran annonaceous acetogenins were evaluated: the cytotoxic (against three human tumor cell lines), antifungal (against Paracoccidioides brasiliensis), trypanocidal (against Trypanosoma cruzi) and leishmanicidal (against Leishmania amazonensis) activities. Acetogenins presented cytotoxic activity confirming their potential use in anti-cancer therapy. Regarding leishmanicidal and trypanocidal activities, an inhibition of 87% of L. amazonensis amastigotes and 100% of T. cruzi amastigotes and trypomastigotes was observed, when tested at the concentration of 20 µg mL-1. Moreover, six acetogenins showed more activity against all the three tested isolates of P. brasiliensis than trimethoprim-sulfamethoxazole, a drug used for treating paracoccidioidomycosis. Thus, acetogenins may be an alternative in treating a number of diseases that have a huge impact on millions of people worldwide. This paper reports for the first time the antifungal, leishmanicidal and trypanocidal activities for these acetogenins.

RESUMEN

We surveyed the distribution and diversity of fungi associated with eight macroalgae from Antarctica and their capability to produce bioactive compounds. The collections yielded 148 fungal isolates, which were identified using molecular methods as belonging to 21 genera and 50 taxa. The most frequent taxa were Geomyces species (sp.), Penicillium sp. and Metschnikowia australis. Seven fungal isolates associated with the endemic Antarctic macroalgae Monostroma hariotii (Chlorophyte) displayed high internal transcribed spacer sequences similarities with the psychrophilic pathogenic fungus Geomyces destructans. Thirty-three fungal singletons (66%) were identified, representing rare components of the fungal communities. The fungal communities displayed high diversity, richness and dominance indices; however, rarefaction curves indicated that not all of the fungal diversity present was recovered. Penicillium sp. UFMGCB 6034 and Penicillium sp. UFMGCB 6120, recovered from the endemic species Palmaria decipiens (Rhodophyte) and M. hariotii, respectively, yielded extracts with high and selective antifungal and/or trypanocidal activities, in which a preliminary spectral analysis using proton nuclear magnetic resonance spectroscopy indicated the presence of highly functionalised aromatic compounds. These results suggest that the endemic and cold-adapted macroalgae of Antarctica shelter a rich, diversity and complex fungal communities consisting of a few dominant indigenous or mesophilic cold-adapted species, and a large number of rare and/or endemic taxa, which may provide an interesting model of algal-fungal interactions under extreme conditions as well as a potential source of bioactive compounds.

Asunto(s)

Hongos/fisiología , Algas Marinas/microbiología , Regiones Antárticas , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , ADN Espaciador Ribosómico/genética , Hongos/química , Hongos/clasificación , Hongos/genética , Hongos/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Agua de Mar/química , Agua de Mar/microbiología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Tubulina (Proteína)/genética

RESUMEN

In our previous work (Fabri et al. 2009), we showed that different extracts of Mitracarpus frigidus had significant antibacterial, antifungal and leishmanicidal activities. In order to increase our knowledge about this species, this work assesses the chemical composition and the in vitro biological activity of its essential oil. Thus, the essential oil obtained by hydrodistillation of the aerial parts of M. frigidus was analyzed by GC/MS. Among several compounds detected, 11 were identified, being linalool and eugenol acetate the major components. The essential oil exhibited a moderate antibacterial effect against Staphyloccocus aureus, Bacillus cereus, Pseudomonas aeruginosa and Enterobacter cloacae (MIC 250 µg/mL). On the other hand, it showed a strong antifungal effect against Cryptoccocus neoformans (MIC 8 µg/mL) and Candida albicans (MIC 63 µg/mL). Expressive activity against L. major and L. amazonensis promastigote forms with IC50 values of 47.2 and 89.7 µg/mL, respectively, were also observed. In addition, the antioxidant activity was investigated through DPPH radical-scavenging and showed a significative activity with IC50 of 38 µg/mL. The cytotoxicity against Artemia salina was moderate with LC(50) of 88 µg/mL. The results presented here are the first report on the chemical composition and biological properties of M. frigidus essential oil.

Asunto(s)

Antibacterianos/farmacología , Antifúngicos/farmacología , Antiprotozoarios/farmacología , Aceites Volátiles/farmacología , Rubiaceae/química , Animales , Antibacterianos/aislamiento & purificación , Antifúngicos/aislamiento & purificación , Antiprotozoarios/aislamiento & purificación , Candida albicans/efectos de los fármacos , Cryptococcus neoformans/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Leishmania/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Pruebas de Sensibilidad Parasitaria , Rubiaceae/clasificación

RESUMEN

Many phenolic compounds such as xanthones, quinones and coumarins have been isolated from Kielmeyera species; however the presence of flavonoids have been showed in other genera in the Calophylleae tribe as Caraipa, Mesua and Calophyllum. Six known glycosidic flavonoids: quercetin 3-β-O-galactopyranoside (1), quercetin 3-β-O-glucopyranoside (2), quercetin 3-O-α-rhamnoside (3), luteolin 6-C-β-glucopyranoside (4), isovitexin (5), kaempferol 3-O-α-rhamnoside (6) and one triterpene, lupenone (7) were isolated, for the first time, from organic crude extract of Kielmeyera variabilis Mart. & Zucc., Calophyllaceae, leaves. The crude organic extract from K. variabilis leaves exhibited 95% of leishmanidal activity at 20 µg/mL on amastigote-like form of Leishmania (Leishmania) amazonensis in vitro model and only compound 3 showed 40-45% of growth inhibition at concentration ranging from 0.78 to 20 µg/mL. In addition, quercetin 3-O-α-rhamnoside (quercitrin) was found to be the major metabolite. Our results and previous reports suggest that synergistic effects of flavonoid glycosides are the cause of significant leishmanidal activity of the crude organic extract from K. variabilis leaves.

RESUMEN

Paracoccidioidomycosis is a prevalent systemic mycosis in Latin America which requires prolonged treatment with highly toxic antifungals. Baccharis dracunculifolia is a medicinal plant in Brazil that is a candidate in the search for new drugs. Fractions of the hexanic extracts were obtained using chromatographic procedures and assessed using an antifungal assay with Paracoccidioides brasiliensis (Pb18), tumor cell lines and amastigote forms of Leishmania, L. amazonensis. Four compounds were isolated, i.e., ursolic acid (1), methyl linolenate (2), caryophyllene oxide (3), and trans-nerolidol (4). Compounds 2, 3 and 4 displayed antifungal activity against four isolates of Paracocci dioides with MIC values ranging from 3.9-250 µg/ml. Only caryophyllene oxide showed differences in the MIC values against Pb18 when the medium was supplemented with ergosterol, which suggested that the compound interacts with ergosterol. Ursolic acid was active in the cytotoxic assays and showed leishmanicidal activity. Scanning electron microscopy demonstrated that compounds 2, 3 and 4 decreased the cell size and produced an irregular cell wall surface on P. brasiliensis cells. The present results showed the biological activities of the isolated compounds and revealed that these compounds may affect the cell surface and growth of P. brasiliensis isolates.

Asunto(s)

Antifúngicos/farmacología , Baccharis/química , Paracoccidioides/efectos de los fármacos , Extractos Vegetales/farmacología , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Brasil , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fraccionamiento Químico , Cromatografía , Humanos , Leishmania/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Paracoccidioides/ultraestructura , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación

RESUMEN

The diversity and antimicrobial activity of endophytic fungi associated with the Brazilian medicinal plant Solanum cernuum Vell. were studied during summer and winter seasons. A total of 246 fungal isolates were obtained, including 225 filamentous fungi and 21 yeasts. They were identified by morphological, physiological, and molecular methods. Fifty-five different taxa represented by the phyla Ascomycota (33 taxa), Basidiomycota (21 taxa), and Zygomycota (one taxon) were identified. The most abundant taxa were closely related to Arthrobotrys foliicola , Colletotrichum gloeosporioides , Coprinellus radians , Glomerella acutata , Diatrypella frostii , Phoma glomerata , Mucor sp., Phlebia subserialis , Phoma moricola , Phanerochaete sordida , and Colletotrichum sp. A total of 265 fungal extracts were screened and 64 (26.01%) displayed antimicrobial activities. Among these extracts, 18 (28.12%) presented antibacterial and antifungal activities, 42 (65.62%) displayed selective antibacterial activity, and four (6.25%) exhibited only antifungal activity. The best values of minimum inhibitory concentration were obtained from extracts of Cryptococcus rajasthanensis , Glomerella acutata, Leptosphaeria sp., and Phoma glomerata ranging from 7.8 to 15.62 µg/mL. This study is the first survey of the endophytic fungi community associated with S. cernuum, and our results show that they can represent a promising source of bioactive compounds.

Asunto(s)

Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Biodiversidad , Hongos/efectos de los fármacos , Hongos/fisiología , Plantas Medicinales/microbiología , Solanum/microbiología , Antiinfecciosos/aislamiento & purificación , Brasil , Mezclas Complejas/farmacología , ADN Espaciador Ribosómico/genética , Endófitos , Hongos/química , Hongos/clasificación , Hongos/genética , Hongos/aislamiento & purificación , Genes de ARNr/genética , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Filogenia

RESUMEN

A total of 564 isolates of endophytic fungi were recovered from the plants Deschampsia antarctica and Colobanthus quitensis collected from Antarctica. The isolates were screened against parasites Leishmania amazonensis and Trypanosoma cruzi and against the human tumour cell lines. Of the 313 fungal isolates obtained from D. antarctica and 251 from C. quitensis, 25 displayed biological activity. Nineteen extracts displayed leishmanicidal activity, and six inhibited the growth of at least one tumour cell line. These fungi belong to 19 taxa of the genera Alternaria, Antarctomyces, Cadophora, Davidiella, Helgardia, Herpotrichia, Microdochium, Oculimacula, Phaeosphaeria and one unidentified fungus. Extracts of 12 fungal isolates inhibited the proliferation of L. amazonesis at a low IC(50) of between 0.2 and 12.5 µg ml(-1). The fungus Phaeosphaeria herpotrichoides displayed only leishmanicidal activity with an IC(50) of 0.2 µg ml(-1), which is equivalent to the inhibitory value of amphotericin B. The extract of Microdochium phragmitis displayed specific cytotoxic activity against the UACC-62 cell line with an IC(50) value of 12.5 µg ml(-1). Our results indicate that the unique angiosperms living in Antarctica shelter an interesting bioactive fungal community that is able to produce antiprotozoal and antitumoral molecules. These molecules may be used to develop new leishmanicidal and anticancer drugs.

Asunto(s)

Caryophyllaceae/microbiología , Endófitos/fisiología , Hongos/fisiología , Leishmania , Neoplasias , Poaceae/microbiología , Animales , Regiones Antárticas , Línea Celular Tumoral , Endófitos/química , Hongos/química , Humanos , Concentración 50 Inhibidora

RESUMEN

Blepharocalyx salicifolius (Kunth) O. Berg, Myrtaceae, is an endemic species that occurs at Southern America. This species was studied to intend to isolation of the active compounds that could be used in vitro model against leishmaniosis, tumoral cell and paracoccidioidomycosis. After Gel Permeation Chromatography, the ethanolic extract from leaves yielded sixteen fractions. Five compounds were isolated and assayed, showing activity against tumoral cells, from 3.33 to 12.83 µg.mL-1; Leishmania (Leishmania) amazonensis from 2.19 to 20.80 µg.mL-1 and Paracoccidioides brasiliensis from 3.10 to 12.5 µg.mL-1.