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Objectives This study aimed to evaluate endophytic fungi isolated from Tocoyena bullata and Humiria balsamifera plant species for their antimycobacterial and anti-inflammatory activities, focusing on severe pulmonary tuberculosis cases which are often associated with exacerbated inflammation. Methods Mycobacterium suspensions were incubated with the samples for 5 days. RAW 264.7 macrophages stimulated with LPS were also incubated with them for 24 h to assess the inhibition of inflammatory mediator production and cytotoxicity. C57BL/6 mice were infected with Mtb M299 and treated for 15 days with lasiodiplodin (Lasio). Key findings Endophytic fungus Sordaria tamaensis, obtained from T. bullata, was the most promising. Its ethanolic extract impaired mycobacterial growth with MIC50 (µg/ml): 1.5 ± 0.6 (BCG), 66.8 ± 0.1 (H37Rv) and 80.0 ± 0.1 (M299). (R)-(+)-Lasio showed MIC50 92.2 ± 1.8 µg/ml (M299). In addition, Lasio was able to inhibit NO, IL-1β and TNF-α production and was not cytotoxic for macrophages. M. tuberculosis-infected C57BL/6 animals treated by Lasio reduced the number of acid-fast bacilli, lung pathology, leucocyte influx and proinflammatory cytokine production in the lungs. The class IIa fructose 1,6-bisphosphate aldolase was the predicted hypothetical target of Lasio. Conclusions (R)-(+)-Lasio stood out as a promising anti-TB compound, exhibiting anti-inflammatory and antimycobacterial effects, as well as low cytotoxicity.

Microorganisms interact chemically in natural environments; however, the compounds and mechanisms involved in this phenomenon are still poorly understood. Using the cocultivation approach, changes in metabolic profiles due to interactions between endophytic fungal and actinobacterial strains isolated from the plant Lychnophora ericoides (Asteraceae) were assessed. The production of the cytotoxic compound cytochalasin H by the fungus Phomopsis sp. FLe6 was remarkably inhibited in solid and liquid co-cultures with the actinobacteria Streptomyces albospinus RLe7. This was a consequence of the fungal growth inhibition caused by antifungal compounds produced by S. albospinus RLe7, including amphotericin B. Cytochalasin H is not toxic to S. albospinus RLe7, suggesting that this microorganism does not require a defense mechanism to prevent the potentially harmful effects of such fungal compound. By exhibiting various competitive phenotypes, these microbes can control each other's growth when sharing an environment.

Endophytic Actinobacteria are a microbial group that is still poorly investigated. Their association with plants constitutes a unique trait conferring specific biological and chemical features to endophytic Actinobacteria. This contribution discusses aspects of endophytic actinobacterial biology and chemistry comprehensively, including the biosynthesis and total synthesis of secondary metabolites produced in culture. It also presents perspectives for the future of microbial bioactive natural products discovery, with emphasis on the secondary metabolism of endophytic Actinobacteria.

Endophytic actinobacteria from the Brazilian medicinal plant Lychnophora ericoides were isolated for the first time, and the biological potential of their secondary metabolites was evaluated. A phylogenic analysis of isolated actinobacteria was accomplished with 16S rRNA gene sequencing, and the predominance of the genus Streptomyces was observed. All strains were cultured on solid rice medium, and ethanol extracts were evaluated with antimicrobial and cytotoxic assays against cancer cell lines. As a result, 92% of the extracts showed a high or moderate activity against at least one pathogenic microbial strain or cancer cell line. Based on the biological and chemical analyses of crude extracts, three endophytic strains were selected for further investigation of their chemical profiles. Sixteen compounds were isolated, and 3-hydroxy-4-methoxybenzamide (9) and 2,3-dihydro-2,2-dimethyl-4(1H)-quinazolinone (15) are reported as natural products for the first time in this study. The biological activity of the pure compounds was also assessed. Compound 15 displayed potent cytotoxic activity against all four tested cancer cell lines. Nocardamine (2) was only moderately active against two cancer cell lines but showed strong activity against Trypanosoma cruzi. Our results show that endophytic actinobacteria from L. ericoides are a promising source of bioactive compounds.

Actinobacteria are the major source of bioactive secondary metabolites and are featured in the search for antimicrobial compounds. We used nuclear magnetic resonance (RMN)-metabolic profiling and multivariate data analysis (MVDA) to correlate the metabolites' production of Streptomyces sp. PNM-9 from the algae Dictyota sp. and their biological activity against the rice phytopathogenic bacteria Burkholderia spp. The compounds 2-methyl-N-(2'-phenylethyl)-butanamide (1) and 3-methyl-N-(2'-phenylethyl)-butanamide (2) were identified through MVDA and 2D NMR experiments in the organic extract of a 15-days LB media culture of Streptomyces sp. PNM-9. Compounds 1 and 2 were isolated and their structures confirmed by one- and two-dimensional NMR and mass spectrometry (MS) data. Compounds 1 and 2 were active against the rice pathogenic bacteria Burkholderia glumae (ATCC 33,617) displaying minimal inhibitory concentration (MIC) values of 2.43 mM and 1.21 mM, respectively. The metabolomics-guided approach employing NMR-metabolic profiling was useful for marine microbial bioprospecting and suggested Streptomyces sp. PNM-9 strain and its compounds as a potential control against phytopathogenic bacteria.

Microorganisms are found everywhere, and they are closely associated with plants. Because the establishment of any plant–microbe association involves chemical communication, understanding crosstalk processes is fundamental to defining the type of relationship. Although several metabolites from plants and microbes have been fully characterized, their roles in the chemical interplay between these partners are not well understood in most cases, and they require further investigation. In this review, we describe different plant–microbe associations from colonization to microbial establishment processes in plants along with future prospects, including agricultural benefits.

During an investigation of the chemistry of the endophytic actinobacterium Streptomyces albospinus RLe7, which was isolated from the roots of the Brazilian medicinal plant Lychnophora ericoides, three new natural products, (2R*,4S*)-2-((1'S*)-hydroxy-4'-methylpentyl)-4-(hydroxymethyl)butanolide (1), (3R*,4S*,5R*,6S*)-tetrahydro-4-hydroxy-3,5,6-trimethyl-2-pyranone (2), and 1-O-(phenylacetyl)glycerol (3), together with known secondary metabolites (S)-4-benzyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (4), (S)-4-isobutyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (5), and the diketopiperazines cyclo(l-Tyr-l-Pro) (6) and cyclo(l-Val-l-Pro) (7), were isolated. The role of isolated natural products in the interaction between S. albospinus RLe7 and the fungus Coniochaeta sp. FLe4, an endophyte from the same plant, was investigated. None of these isolated actinobacterial compounds were able to inhibit the fungus or induce the fungal red pigmentation observed when both endophytes interact. Further investigation using mass spectrometry approaches enabled identifying the well-known antifungal compound amphotericin B (9) as a microbial metabolite of S. albospinus RLe7. Finally, compound 9 was demonstrated as at least one of the agents responsible for both the antifungal activity and induction of red-pigmented fungal phenotype.

Microorganisms interact with each other via metabolic exchange. Several studies have revealed that microbial metabolites may act as mediators of microbial interactions. During our previous work with endophytes isolated from the Brazilian medicinal plant Lychnophora ericoides, we demonstrated that the well-known antifungal compound amphotericin B, produced by the endophytic actinobacterium Streptomyces albospinus RLe7, may trigger chemical responses in endophytic fungi. In this study, we cultured endophytic fungi in amphotericin B-enriched media to verify whether other chemical responses could be induced. Interestingly, one fungal strain showed a differential response under the tested conditions. When the fungus Xylaria cubensis FLe9 was cultured in amphotericin B-enriched media, a mycelial guttate was observed. Investigation of the fungal extracts from X. cubensis FLe9 and purification of fungal metabolites were performed using high-performance liquid chromatography coupled to a diode array detector. Isolated compounds were characterized on the basis of nuclear magnetic resonance and mass spectrometry data. Therefore, we report on the overproduction of the fungal metabolites griseofulvin (1) and dechlorogriseofulvin (2) when the endophytic fungus Xylaria cubensis FLe9 was exposed to amphotericin B. Both fungal compounds 1 and 2 were also detected in the mycelial guttate produced when X. cubensis FLe9 was exposed to amphotericin B. Since the amphotericin B-producing actinobacterium S. albospinus RLe7 and the griseofulvin-producing fungus X. cubensis FLe9 are endophytes from the same host, biosynthetic induction of fungal compounds may suggest a potential signaling role for amphotericin B in natural environments. However, this hypothesis needs to be further investigated in field experiments.

Secondary metabolites produced by endophytic microorganisms can provide benefits to host plants, such as stimulating growth and enhancing the plant's resistance toward biotic and abiotic factors. During its life, a host plant may be inhabited by many species of endophytes within a restrictive environment. This condition can stimulate secondary metabolite production that improves microbial competition and may consequently affect both the neighboring microorganisms and the host plant. The interactions between the endophytes that co-habit the same host plant have been studied. However, the effect of these interactions on the host plant has remained neglected. When using mixed microbial cultures, we found that the endophytic fungus Alternaria tenuissima significantly increased the production of some polyketides, including antifungal stemphyperylenol in response to the endophytic Nigrospora sphaerica. Biological activity assays revealed that stemphyperylenol can cause cytotoxic effects against N. sphaerica, although no phytotoxicity was observed in the host plant Smallanthus sonchifolius, even at concentrations much higher than those toxic to the fungus. The polyketides produced by A. tenuissima may be important for the ecological relationships between endophyte-endophyte and endophytes-host plants in the natural environment.

We report here the complete genome sequence of Streptomyces sp. strain RTd22, an endophytic actinobacterium that was isolated from the roots of the Mexican sunflower Tithonia diversifolia . The bacterium's 11.1-Mb linear chromosome is predicted to encode a large number of unknown natural products.

Three new natural products, 1,4,6b,7,10-pentahydroxy-1,2,6b,7,8,12b-hexahydroperylene-3,9-dione (1), 1,4,9,12a-tetrahydroxy-12-methoxy-1,2,11,12,12a,12b-hexahydroperylene-3,10-dione (2) and 1,4,9-trihydroxy-1,2-dihydroperylene-3,10-dione (3), were obtained from cultures of the endophytic fungus Alternaria tenuissima SS77. Their chemical structures were determined by combined analysis of one- and two-dimensional NMR spectra, UV and ESIHRMS data. Compound 3 is likely an intermediate in the biosynthetic pathway of some perylenequinones produced by this fungus. A new hypothesis for the biosynthesis of partially reduced perylenequinones is suggested.

Smallanthus sonchifolius is a traditional Andean plant which has been cultured mainly in Brazil, Japan and New Zealand due to its medicinal properties. A study of the endophytic fungi associated to the plant was carried out in order to characterize new cytotoxic agents. Thirty two fungal strains were isolated and submitted to cultivation and extraction producing 186 extracts. Of these, 12% displayed moderate to high cytotoxic activities and were considered promising anticancer compound sources. The ethyl acetate fractions of Nigrospora sphaerica and Phoma betae liquid fermentations contained the synergistic compounds 8-hydroxy-6-methoxy-3-methylisocoumarin and (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one which are potential compounds for drug discovery. Another isolated compound, pimara-7,15-dien-3-beta-ol diterpene is being characterized for the first time through a detailed spectroscopic analysis including GC/MS, homo- and hetero-nuclear correlated NMR experiments (HMQC, HMBC, COSY and NOEdiff) along with its optical rotation.

Microorganisms inhabiting plant tissues without causing any damage to their host plant are referred to as endophytes and can be fungi or bacteria, including actinobacteria. Due to a direct interaction between plant and endophytes, these microorganisms are an interesting source for biologically active natural products. Here, we reviewed the novel compounds isolated from endophytic fungi from 2012 to April 2014, mentioning their biological activities as well as their biological sources. Only secondary metabolites containing any interesting structural novelty or relevant biological activity were highlighted. The novel metabolites were classified into four major groups based on their biosynthetic pathway, such as polyketide and fatty acid, phenylpropanoid, and terpenoid derivatives as well as N-containing compounds. Taking into account that laboratorial conditions may lead to a minimal or absent production of many interesting microbial metabolites produced by the endophytes while interacting in their natural habitat, some approaches have been applied to the endophytes cultures and some examples of new metabolites obtained by using those strategies are also mentioned.

Made available in DSpace on 2015-02-02T12:39:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-10-01Bitstream added on 2015-02-02T13:07:46Z : No. of bitstreams: 1 S0103-50532014001000014.pdf: 3421821 bytes, checksum: 31cb273815239fbaf24b7dc1833deab8 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Recentes estudos demonstraram que afidicolina, metabólito secundário do fungo endofítico Nigrospora sphaerica, apresenta alta atividade contra o protozoário Leishmania major. Apesar do promissor potencial leishmanicida, a afidicolina apresenta propriedades físico-químicas e perfil farmacocinético inadequado para terapêutica. Neste sentido, uma revisão da literatura apresenta as limitadas modificações para este terpeno e ainda traz informações sobre as propriedades moleculares dos compostos já descritos e sua correlação com compostos leishmanicidas. Essa revisão forneceu uma análise racional para o desenvolvimento do derivado oxima. Uma série de derivados da afidicolina bem como o análogo oxima foram sintetizados para avaliação preliminar dos requisitos estruturais para atividade leishmanicida da afidicolina e seus derivados semi-sintéticos. Oito compostos foram sintetizados e testados contra diferentes espécies de Leishmania. A avaliação preliminar demonstrou alta atividade leishmanicida da afidicolina enquanto que o derivado oxima apresenta moderada seletividade contra a espécie L. braziliensis, endêmica em diversos países da América do Sul. Nenhum dos compostos apresentou citotoxicidade contra células de mamíferos. Recent studies have shown that aphidicolin, a secondary metabolite of the endophytic fungus Nigrospora sphaerica, has high activity against the protozoan Leishmania major. Despite its promising leishmanicidal potential, aphidicolin presents a therapeutically unsuitable physico-chemical and pharmacokinetic profile. In this sense, a review of the literature shows the limited types of modification for this terpene. In addition, it gives an idea about the molecular properties of the compounds produced and which were correlated to leishmanicidal derivatives. This analysis provided us a rationale for the development of an oxime derivative. We synthesized the oxime-aphidicolin and a series of derivatives for a preliminary evaluation of the structural requirements for the leishmanicidal activity of aphidicolin and its semisynthetic derivatives. Eight compounds have been synthesized and tested against different species of the Leishmania protozoa. The preliminary evaluation demonstrated high leishmanicidal activity for aphidicolin, while the oxime derivative shows moderate selectivity for the L. braziliensis species, which is commonly found in several South American countries. None of the compounds showed cytotoxicity against mammalian cells. Universidade de São Paulo Faculdade de Ciências Farmacêuticas de Ribeirão Preto Departamento de Ciências Farmacêuticas Universidade de São Paulo Faculdade Medicina de Ribeirão Preto Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências Letras e Ciências Exatas de São José do Rio Preto Departamento de Física Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências Letras e Ciências Exatas de São José do Rio Preto Departamento de Física