Análise por HPLC e Espectrometria de Massas do Extrato Alcaloídico Hexânico das Folhas de Annona muricata/ HPLC and Mass Spectrometry analysis of Hexane Extract Alkaloidal from the Leaves of Annona muricata

Annona muricata, uma planta frutífera da região amazônica, muito apreciada pelo seu fruto, a graviola, comum na região Amazônica e bastante estudada devido aos seus componentes químicos, alcalóides e acetogeninas. Com base nessas informações, neste trabalho relata-se a análise via HPLC e Espectrometria de massas do extrato alcaloídico obtido a partir do extrato hexânico das folhas, via partição ácido/ base

Síntese de Análogo da Curcumina: (1E,4E) -1,5-Bis-(2-metóxi-fenil) -penta-1,4-dien-3-ona / Synthesis of Curcumin Analogous: (1E, 4E) -1,5-Bis- (2-methoxy-phenyl) -pent-1,4-dien-3-one

Este trabalho relata a síntese e caracterização de (1E,4E) -1,5-Bis-(2-metóxi-fenil)-penta-1,4-dien-3-ona, a partir de (3E)-4-(2-metóxi-fenil)-but-3-en-2-ona. Essa substância representa um análogo da Dibenzalcetona, chamadas de curcuminas. Inicialmente, preparou-se o material de partida em seguida reagiu-se com orto-anisaldeído, utilizando a reação de condensação de Claisen-Schmidt. As substâncias foram obtidas em bom rendimento e identificadas por RMN de Hidrogênio e Carbono-13

Esteroides produzidos por Penicillium herquei, um fungo endofítico isolado dos frutos de Melia azedarach (Meliaceae)

Six compounds comprising the groups of steroids, the ergosterol, the ergosterol peroxide, the cerevisterol, the neociclocitrinols, the ergosta-4,6,8(14),22-tetraen-3-one, the 25-hydroxy-ergosta-4,6,8(14),22-tetraen-3-one, were isolated from Penicillium herquei fungus obtained from Melia azedarach. The structures were identified by spectral methods of RMN 1D and 2D and MS

Molecular characterization and in silico evaluation of surfactins produced by endophytic bacteria from Phanera splendens

National Council for Scientific and Technological Development (CNPq - Grant: 308631/2021-8; Grant: 310540/2022- 4; Grant: 406269/2022-0), the Federal Agency for Support and Evaluation of Graduate Education (CAPES) and the Postgraduate Pro-Research (PROPESP/UFPA).Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Laboratório de Bioensaios e Química de Microrganismos. Belém, PA, Brazil.Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Laboratório de Planejamento e Desenvolvimento de Fármacos. Belém, PA, Brazil.Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Laboratório de Bioensaios e Química de Microrganismos. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Laboratório de Bioensaios e Química de Microrganismos. Belém, PA, Brazil.Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Laboratório de Bioensaios e Química de Microrganismos. Belém, PA, Brazil.Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Laboratório de Planejamento e Desenvolvimento de Fármacos. Belém, PA, Brazil.The Phanera splendens (Kunth) Vaz. is a medicinal plant that is used in traditional medicine for the treatment of various diseases, such as malaria. This plant presents highly efficient endophytic bacterial isolates with biocontrol properties. Bacillus sp. is responsible for the production of a variety of non-ribosomal synthesized cyclic lipopeptides which highlight the surfactins. Surfactins have a wide range of antimicrobial activity, including antiplasmodial activity. There is scientific evidence that surfactin structure 2d-01 can be a potent inhibitor against a Plasmodium falciparum sirtuin (Sir2) by acting on the Sir2A protein as the target. The Pf genome encodes two known sirtuins, PfSir2A and PfSir2B, where PfSir2A is a regulator of asexual growth and var gene expression. Herein, we have identified six surfactins produced by endophytic bacteria and performed in silico analysis to elucidate the binding mode of surfactins at the active site of the PfSir2A enzyme. Among the characterized surfactins, 1d-02 showed the highest affinity for the PfSir2A enzyme, with binding energy values equal to −45.08 ± 6.0 and −11.95 ± 0.8 kcal/mol, using MM/GBSA and SIE methods, respectively. We hope that the information about the surfactin structures obtained in this work, as well as the potential binding affinity with an important enzyme from P. falciparum, could contribute to the design of new compounds with antimalarial activity

Phomoxanthone A, Compound of Endophytic Fungi <i>Paecilomyces</i> sp. and Its Potential Antimicrobial and Antiparasitic

The present work reports the isolation and biological evaluation of three dimeric xanthones from Paecilomyces sp. EJC01.1 isolated as endophytic from Schnella splendens, a typical plant of the Amazon. The compounds phomoxanthone A (1), phomoxanthone B (2) and dicerandrol B (3) were isolated by chromatographic procedures and identified by spectroscopic methods of 1D and 2D NMR and MS. The extracts and compound 1 showed antimicrobial activities against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Pseudomonas aeruginosa. The compound phomoxanthone A (1) showed greater inhibitory activity against B. subtilis (MIC of 7.81 µg mL−1); in addition, it also pronounced inhibitory effect against promastigote forms of Leishmania amazonensis (IC50 of 16.38 ± 1.079 µg mL−1) and epimastigote forms Trypanosoma cruzi (IC50 of 28.61 ± 1.071 µg mL−1). To provide more information about the antibacterial activity of compound 1, an unprecedented molecular docking study was performed using S-ribosyl-homocysteine lyase (LuxS) (PDB ID 2FQO), which showed a possible interaction of phomoxanthone A with two of the residues (His58 and Cys126) that are fundamental for the catalysis mechanism in B. subtilis, which may be associated with the higher activity, when compared to other bacteria, observed in experimental studies. Additionally, quantum studies (DFT) were performed, for which a low gap value (5.982 eV) was observed, which corroborates the reactivity of phomoxanthone A. Thus, phomoxanthone A can be a good agent against pathogenic bacteria

Antiprotozoal and Antibacterial Activity of Ravenelin, a Xanthone Isolated from the Endophytic Fungus Exserohilum rostratum

The natural compound ravenelin was isolated from the biomass extracts of Exserohilum rostratum fungus, and its antimicrobial, antiplasmodial, and trypanocidal activities were evaluated. Ravenelin was isolated by column chromatography and HPLC and identified by NMR and MS. The susceptibility of Gram-positive and Gram-negative bacteria strains to ravenelin was determined by microbroth dilution assay. Cytotoxicity was evaluated in hepatocarcinoma cells (HepG2) and BALB/c peritoneal macrophages by using MTT. SYBR Green I-based assay was used in the asexual stages of Plasmodium falciparum. Trypanocidal activity was tested against the epimastigote and intracellular amastigote forms of Trypanosoma cruzi. Ravenelin was active against Gram-positive bacteria strains, with emphasis on Bacillus subtilis (MIC value of 7.5 µM). Ravenelin’s antiparasitic activities were assessed against both the epimastigote (IC50 value of 5 ± 1 µM) and the intracellular amastigote forms of T. cruzi (IC50 value of 9 ± 2 µM), as well as against P. falciparum (IC50 value of 3.4 ± 0.4 µM). Ravenelin showed low cytotoxic effects on both HepG2 (CC50 &gt; 50 µM) and peritoneal macrophage (CC50 = 185 ± 1 µM) cells with attractive selectivity for the parasites (SI values &gt; 15). These findings indicate that ravenelin is a natural compound with both antibacterial and antiparasitic activities, and considerable selectivity indexes. Therefore, ravenelin is an attractive candidate for hit-to-lead development

Antimicrobial Activity and Molecular Docking Studies of the Biotransformation of Diterpene Acanthoic Acid Using the Fungus <i>Xylaria</i> sp.

Biotransformations are reactions mediated by microorganisms, such as fungi. These bioreactions have high chemo- and stereoselectivity on organic substrates and can be applied in the search for new bioactive compounds. In this study, acanthoic acid (AA) was biotransformed using the fungus Xylaria sp., giving the novel compound 3β,7β-dihydroxyacanthoic acid (S1). Both the AA and the product S1 were tested against Gram-positive and Gram-negative bacteria. To identify and validate possible biological targets as enzymes or proteins involved in the activity observed in vitro, we used the molecular docking method. Hydroxylation at the C-3 and C-7 positions of the biotransformation product enhanced its activity against Escherichia coli as well as its binding affinity and interactions with superoxide dismutase 1 (SOD1; PDB ID 4A7G). Based on our results, the SOD1 enzyme was suggested to be a possible target for the antioxidant activity of product S1

Novel anthraquinone derivatives produced by Pestalotiopsis guepinii, an endophytic of the medicinal plant Virola michelii (Myristicaceae)

Um novo derivado de antraquinona, denominado guepinone (1), juntamente com as conhecidas substâncias isossulocrina (2) e cloroissosulocrina (3) foram isolados de uma cultura em arroz de Pestalotiopsis guepinii, um fungo endofitico de Virola michelii. Os compostos foram identificados pela análise de seus dados espectrométricos de RMN 1D e 2D e EM. A atividade antimicrobiana dos compostos isolados foi avaliada e a cloroisossulcrina (3) foi a mais ativa.ABSTRACT: A new anthraquinone derivative, named guepinone (1), along with the known substances isosulochrin (2) and chloroisosulochrin (3), were isolated from a rice culture of Pestalotiopsis guepinii, an endophytic fungus of Virola michelii. The compounds were identified by analysis of 1D and 2D NMR and MS spectral data. The antimicrobial activity of these compounds was evaluated and chloroisosulchrin (3) was the most active