Resumo Apresentamos um levantamento comentado de projetos financiados pelo programa BIOTA-Micro-organismos. Estes projetos geraram uma variada gama de resultados, incluindo a identificação de novos micro-organismos produtores de compostos antibacterianos, a caracterização de novas enzimas microbianas para usos industriais, classificação taxonômica de novos micro-organismos presentes em diversos ambientes, investigação de ecossistemas microbianos em solos e mangues e sua influência sobre plantas ameaçadas, e o sequenciamento de vários novos genomas microbianos derivados de metagenomas. Os resultados descritos demonstram o papel-chave de micro-organismos em ecossistemas importantes para atividades humanas, assim como o potencial que vários desses micro-organismos tem de contribuir para aplicações biotecnológicas cruciais para a sobrevivência humana no século 21.

Abstract We present a survey of projects that have been funded by FAPESP under the BIOTA-Microorganisms program. These projects generated a wide variety of results, including the identification of novel antibacterial-producing microorganisms, the characterization of novel microbial enzymes for industrial applications, taxonomic classification of novel microorganisms in several environments, investigation of the soil and mangrove microbial ecosystems and its influence on endangered plant species, and the sequencing of novel metagenome-assembled genomes. The results surveyed demonstrate the importance of microorganisms in environments that play important roles in human activities as well as the potential that many of these microorganisms have in contributing to biotechnological applications crucial for human survival in the 21st century.

The phytochemical study of Hippeastrum goianum led to the identification of 13 compounds by means of gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). Compounds 7-demethoxy-9-O-methylhostasine (1) and 7-deoxi-trans-dihydronarciclasine (2) had their absolute configurations determined by vibrational circular dichroism (VCD). This is the first time that compound 1 is described in the Amaryllidaceae family. The cytotoxicity of all isolated compounds was tested against colorectal carcinoma (HCT 116), breast carcinoma (MCF-7), and non-tumor human retinal pigment epithelium (RPE) cell lines. The half-maximum inhibitory concentration (IC50) of compound 2 against each cell line was equivalent to the positive control (doxorubicin), indicating a considerable cytotoxic activity.

Abstract Pharmaceuticals occur in the environment due to their excessive consumption and the inefficiency of treatment plants to degrade, inactivate or remove them. Diazepam (DZP) stands out as the most consumed benzodiazepine, and induces sedative effects and reduces anxiety. Considering its potential appearance in several environmental compartments, the aim of the present study was to determine the effects of DZP under acute and chronic exposures on the mysid Mysidopsis juniae. Mortality was assessed using an acute toxicity test and a LC50 of 3.7 ± 0.5 mg·L-1was derived. The mass and length of the mysids was recorded in the chronic exposure to test for sublethal effects, and concentrations of 0.25 and 0.5 mg·L-1 of DZP affected mysids length and dry weight, respectively. Although effect-inducing concentrations used in this study are above environmentally relevant levels, the present study adds value to the limited available data for DZP toxicity to marine organisms, and we have shown that M. juniae is the most sensitive marine crustacean species tested thus far.

ABSTRACT The 1,2-naphthoquinone compound was previously considered active against solid tumors. Moreover, glycosidase inhibitors such as 1,2,3-1H triazoles has been pointed out as efficient compounds in anticancer activity studies. Thus, a series of eleven 1,2-naphthoquinones tethered in C2 to 1,2,3-1H-triazoles 9a-k were designed, synthesized and their cytotoxic activity evaluated using HCT-116 (colon adenocarcinoma), MCF-7 (breast adenocarcinoma) and RPE (human nontumor cell line from retinal epithelium). The chemical synthesis was performed from C-3 allylation of lawsone followed by iodocyclization with subsequent nucleophilic displacement with sodium azide and, finally, the 1,3-dipolar cycloaddition catalyzed by Cu(I) with terminal alkynes led to the formation of 1H-1,2,3-Triazol-1-ylmethyl-2,3-dihydronaphtho[1,2-b]furan-4,5-diones in good yields. Compounds containing aromatic group linked to 1,2,3-triazole ring (9c, 9d, 9e, 9i) presented superior cytotoxic activity against cancer cell lines with IC50 in the range of 0.74 to 4.4 µM indicating that the presence of aromatic rings substituents in the 1,2,3-1H-triazole moiety is probably responsible for the improved cytotoxic activity.

Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known related diterpenes were isolated from the aerial parts of cultivated specimens of Plectranthus ornatus. The structures were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS) and comparison with published NMR data of analogous compounds. All isolated compounds were assayed against four human cancer cell lines, and Gram-positive and Gram-negative bacteria strains. None of them showed any cytotoxic activity, but ornatin C, D, E and three related diterpenes displayed marginal bactericidal or bacteriostatic effects against the Gram-positive strains.

The actinomycete strain BRA 177 was recovered from sediment samples collected at the St. Peter and St. Paul Archipelago, Brazil. This work accessed the ability of this strain, identified as Actinomadura sp., to produce bioactive metabolites by exploring the genome and characterizing chemistry and cytotoxicity of isolated compounds. From the crude ethyl acetate extract, the pigments nonylprodigiosin, cyclononylprodigiosin and methylcyclooctilprodigiosin were isolated and displayed cytotoxicity against human tumor and non-tumor cell lines. Sequencing, assembling and prospection of BRA 177 draft genome led to identification of two contigs encoding enzymes with high homology to those from prodiginine biosynthetic gene clusters (BGC) in actinomycetes. Further, Actinomadura sp. BGC presented unique putatives RedJ thioesterase and RedL-like type I PKS, involved on selection of prodiginine biosynthetic fatty acyl precursor, and RedG-like Rieske oxygenase, key for cyclization of the prodiginines, suggesting that cyclononilprodigiosin and methylcyclooctylprodigiosin could actually be considered chemical signatures of Actinomadura spp.

Understanding the target and mode of action (MOA) of small molecules activity has become a critical feature in guiding the transition between drug discovery and clinical evaluation. While classically placed at the latter stages of a discovery program, we now describe how addressing the mode of action of natural products at the early stages of a program provides an important vehicle to inform the drug discovery process. In this review, we outline a streamlined cellular and molecular biological system and explore its utility through a series of four cases studies. We believe that this approach offers critical lessons to guide future drug discovery programs.

Abstract Dinoflagellates are an important source of unique bioactive secondary metabolites. Symbiotic species, commonly named zooxanthellae, transfer most of their photosynthetically fixed carbon to their host. The mutualistic relationship provides the organic metabolites used for energy production but there are very few reports of the role of the dinoflagellates in the production of secondary metabolites in the symbiotic association. Corals and other related cnidarians are the most well-known animals containing symbiotic dinoflagellates. In the present paper we describe the isolation of amphidinolide P (1) from the octocoral Stragulum bicolor and its prey, the nudibranch Marionia limceana, collected off the coasts of Fortaleza (Ceará, Brazil). The coral extracts also contained 3-O-methyl derivative (2) of amphidinolide P, together with minor compounds still under investigation. Amphidinolides have been so far reported only in laboratory cultures of Amphidinium sp., thus compounds 1 and 2 represents the first identification of these polyketides in invertebrates. The finding proves the possibility to isolate amphidinolides from a natural symbiosis, enabling further biological and biotechnological studies.

Seaweeds are potential sources of high biotechnological interest due to production of a great diversity of compounds exhibiting a broad spectrum of biological activities. On the other hand, there is an urgent need for management options for a sustainable approach to the use of marine organisms as a source of bioactive compounds. This review discusses the bioprospection for bioactive seaweed compounds as pharmaceuticals and antifouling agents, encompassing their potential and possible obstacles and alternatives. In spite of their potential, research on pharmaceuticals and antifouling agents from seaweeds includes mainly the search for molecules that exhibit these biological activities, but lacks of consideration of fundamental and limiting aspects such as the development of alternatives to sustainable supply. However, for the complete development of pharmaceuticals and antifouling compounds in Brazil, marine bioprospection should be more comprehensive, associating the search for molecules with an analysis of their supply. In this way, it is possible to promote sustainable development and conservation of biodiversity, as well as to assert the economic development of Brazil.

O estudo fitoquímico do invertebrado marinho Eudistoma vannamei levou ao isolamento de derivados do alcalóide estaurosporina, que apresentaram uma potente atividade citotóxica contra linhagens de células humanas de câncer. A ocorrência destes alcalóides pode ser correlacionada a presença de microorganismos associados ao animal, como por exemplo bactérias do gênero Streptomyces. Visando confirmar essa hipótese, precedeu-se o isolamento e cultivo dos microrganismos associados com E. vannamei (84 cepas isoladas). Estudos sistemáticos das reações de fragmentação da estaurosporina e derivados, apoiados pela química computacional, permitiram definir os principais padrões de fragmentação. Esses padrões foram utilizados em análises exploratórias por LC-MS/MS visando pesquisar a presença de derivados de estaurosporinas nos microrganismos isolados. Esse procedimento permitiu identificar estaurosporina em uma espécie de Streptomyces, contudo não com o mesmo padrão de oxidação da molécula ativa isolada no extrato da Ascídia. Finalmente, o extrato dessa cepa mostrou também significativa atividade citotóxica contra linhagens de câncer.

Former bioactivity-guided analysis of the marine invertebrate Eudistoma vannamei led to the isolation of staurosporine derivatives, which revealed strong cytotoxic activity against several human cancer cell lines. The occurrence of such alkaloids in E. vannamei may be correlated to the presence of associated biota, such as Streptomyces bacteria. In agreement to this hypothesis, marine microorganisms associated with E. vannamei were recovered and cultured, leading to a total of 84 isolated bacterial strains. Gas phase fragmentation reactions of staurosporine and derivatives were systematically studied and the analyzed results further supported by computational chemistry studies. The resulting fragment patterns were used to search for the presence of different derivatives in extracts of isolated microorganisms, thereby using LC-MS/MS analysis in MRM mode. These results evidenced that one isolated Streptomyces sp. was able to generate staurosporine, while none of the hydroxy-7-oxo derivatives were detected. Finally, significant cytotoxic activity against human cancer lines was observed for one of the extracts.

Usos populares e pesquisas científicas têm destacado a importância dos extratos da planta Casearia sylvestris e seu grande potencial bioativo. Neste trabalho, objetiva-se revisar as propriedades farmacológicas de C. sylvestris, enfatizando sua potencialidade antiulcerogênica, antiinflamatória, antiofídica e antitumoral. O extrato etanólico e o óleo essencial das folhas possuem atividade antiulcerogênica promissora, diminuindo o volume gástrico sem alterar o pH estomacal, corroborando sua aplicação contra dores gastrointestinais. Já os extratos aquosos das folhas têm atividade inibitória contra fosfolipase A2 presente em venenos de cobras, atenuando os efeitos lesivos sobre a musculatura esquelética resultantes da inoculação das toxinas. Essa ação antifosfolipásica provavelmente está relacionada ao seu uso como antiinflamatório, sugerindo um bloqueio análogo ao dos fármacos antiinflamatórios não-esteroidais na formação de mediadores oriundos do ácido araquidônico e na ativação da ciclooxigenase. Ensaios de fracionamento bioguiado dos extratos culminaram no isolamento e identificação de inúmeros metabólitos secundários, especialmente os diterpenos clerodânicos casearinas (A-X) e casearvestrinas (AC), compostos que têm surpreendido por sua ação citotóxica e antitumoral. Assim, a planta C. sylvestris apresenta um enorme arsenal farmacológico já mundialmente comprovado por seu vasto uso popular, estimulando pesquisas por novas moléculas e a busca pela compreensão de suas propriedades biológicas.

Folk uses and scientific investigations have highlighted the importance of Casearia sylvestris extracts and their relevant bioactive potential. The aim of this work was to review the pharmacological properties of C. sylvestris, emphasizing its anti-ulcer, anti-inflammatory, anti-ophidian and antitumor potentialities. Ethanolic extracts and essential oil of their leaves have antiulcerogenic activity and reduce gastric volume without altering the stomach pH, which corroborates their consumption on gastrointestinal disorders. Leaf water extracts show phospholipase A2 inhibitory activity that prevents damage effects on the muscular tissue after toxin inoculation. This antiphospholipasic action is probably related to the use as an anti-inflammatory, proposing a pharmacological blockage similar to that obtained with non-steroidal anti-inflammatory drugs on arachidonic acid and cyclooxygenase pathways. Bioguided-assay fractionations lead to the identification of secondary metabolites, especially the clerodane diterpenes casearins (A-X) and casearvestrins (A-C), compounds with a remarkable cytotoxic and antitumor action. Therefore, the C. sylvestris shrub holds a known worldwide pharmacological arsenal by its extensive folk utilization, exciting searches for new molecules and a better comprehension about biological properties.