RESUMO
A new carbazole alkaloid, streptoverticillin, and a new 2-azetidinone, streptoverticillinone, along with three known cyclodipeptides were isolated from the mycelial solid culture of Streptoverticillium morookaense. Their structures were elucidated by analysis of 1D and 2D NMR, mass spectra and optical rotation data. Two new compounds exhibited antifungal activity against Peronophythora litchii.
Assuntos
Alcaloides/biossíntese , Alcaloides/farmacologia , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Streptomyces/metabolismo , Alcaloides/química , Alcaloides/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Carbazóis/química , Carbazóis/isolamento & purificação , Carbazóis/farmacologia , Litchi/microbiologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas/métodos , Testes de Sensibilidade Microbiana , Rotação Ocular , Doenças das Plantas/microbiologia , Pirrolidinas/química , Pirrolidinas/isolamento & purificação , Pirrolidinas/farmacologia , Streptomyces/crescimento & desenvolvimentoRESUMO
A new acetogenin, polyporolide (1), was isolated from the mycelial solid cultures of a Polyporus basidiomycete. Its structure was elucidated as 4-hydroxy-5-(1-hydroxyhexyl)-dihydrofuran-2-one by spectroscopic methods. Its toxicity to brine shrimps was assessed.
Assuntos
Álcoois Graxos/química , Furanos/química , Lactonas/química , Micélio/química , Polyporaceae/química , Acetogeninas , Animais , Artemia/efeitos dos fármacos , China , Cromatografia , Álcoois Graxos/isolamento & purificação , Álcoois Graxos/toxicidade , Fermentação , Furanos/isolamento & purificação , Furanos/toxicidade , Lactonas/isolamento & purificação , Lactonas/toxicidade , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura MolecularRESUMO
Peptidoglycan recognition proteins (PGRPs) are multifunctional pattern recognition proteins. Here, we report that a PGRP gene, BtPGRP, encodes a PGRP from the whitefly Bemisia tabaci (MEAM1) that binds and kills bacteria in vitro. We analyzed BtPGRP transcriptional profiling, and the distribution of the cognate protein within the midgut. Fungal infection and wasp parasitization induced expression of BtPGRP. Silencing BtPGRP with artificial media amended with dsRNA led to reduced expression of a gene encoding an antimicrobial peptide, B. tabaci c-type lysozyme. Begomovirus infection also led to increased expression of BtPGRP. We propose that BtPGRP has a potential Tomato yellow leaf curl virus (TYLCV) binding site because we detected in vitro interaction between BtPGRP and TYLCV by immunocapture PCR, and recorded the co-localization of TYLCV and BtPGRP in midguts. This work addresses a visible gap in understanding whitefly immunity and provides insight into how the whitefly immunity acts in complex mechanisms of Begomovirus transmission among plants.
Assuntos
Begomovirus/fisiologia , Proteínas de Transporte/metabolismo , Hemípteros/imunologia , Hemípteros/virologia , Imunidade , Animais , Sequência de Bases , Proteínas do Capsídeo/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/farmacologia , Clonagem Molecular , Sistema Digestório/virologia , Regulação da Expressão Gênica/efeitos dos fármacos , Solanum lycopersicum/virologia , Testes de Sensibilidade Microbiana , Filogenia , RNA de Cadeia Dupla/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNARESUMO
Two new illudane sesquiterpenes, paneolic acid and paneolilludinic acid, along with a known antibiotic diterpene, pleuromutilin, were isolated from the mycelial solid cultures of Panaeolus retirugis. Their structures were elucidated on the basis of spectroscopic analysis. Both compounds exhibited antibacterial activity against Staphylococcus aureus, and paneolic acid showed cytotoxicity to HL60 cell with an IC50 of 18.9 microg/ml.
Assuntos
Antibacterianos/farmacologia , Basidiomycota/metabolismo , Sesquiterpenos/farmacologia , Antibacterianos/isolamento & purificação , Antibióticos Antineoplásicos/biossíntese , Antibióticos Antineoplásicos/isolamento & purificação , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Fermentação , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Rotação Ocular , Sesquiterpenos/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A 384-well microtitre plate fluorescence cleavage assay was developed to identify inhibitors of the cysteine protease falcipain-2, an important antimalarial drug target. Bioassay-guided isolation of a MeOH extract from a myxobacterium Chitinophaga sp. Y23 isolated from soil collected in Singapore, led to the identification of a new acyltetrapeptide, falcitidin (1), which displayed an IC50 value of 6 µM against falcipain-2. The planar structure of 1 was secured by NMR and MS/MS analysis. Attempts to isolate further material for biological testing were hampered by inconsistent production and by a low yield (<100 µg l(-1)). The absolute configuration of 1 was determined by Marfey's analysis and the structure was confirmed through total synthesis as isovaleric acid-D-His-L-Ile-L-Val-L-Pro-NH2. Falcitidin (1) is the first member of a new class of falcipain-2 inhibitors and, unlike other peptide-based inhibitors, does not contain reactive groups that irreversibly bind to active cysteine sites.
Assuntos
Antimaláricos/isolamento & purificação , Antimaláricos/farmacologia , Cisteína Endopeptidases/metabolismo , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/farmacologia , Inibidores de Proteases/isolamento & purificação , Inibidores de Proteases/farmacologia , Antimaláricos/síntese química , Antimaláricos/química , Bacteroidetes/química , Bacteroidetes/isolamento & purificação , Bioensaio , Avaliação Pré-Clínica de Medicamentos , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/química , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Singapura , Microbiologia do Solo , Espectrometria de Massas em TandemAssuntos
Ascomicetos/química , Benzoquinonas/isolamento & purificação , Benzoquinonas/farmacologia , Antagonistas dos Receptores CCR5 , Stachybotrys/química , Animais , Ascomicetos/metabolismo , Benzoquinonas/química , Benzoquinonas/metabolismo , Ligação Competitiva , Células CHO , Quimiocina CCL4 , Cricetinae , Fermentação , Humanos , Concentração Inibidora 50 , Proteínas Inflamatórias de Macrófagos/metabolismo , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Receptores CCR5/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Stachybotrys/metabolismoRESUMO
Three new sesquiterpenes including a rearranged hirsutane, dichomitol (1), an aromadendrane, 2beta,13-dihydroxyledol (2), and a 1,10-seco-2,3-seco-aromadendrane, dichomitone (3), were isolated from mycelial solid cultures of Dichomitus squalens. Their structures were elucidated by spectroscopic methods, and their nematicidal activities against Bursaphelenchus xylophilus were assessed.
Assuntos
Antinematódeos/isolamento & purificação , Nematoides/efeitos dos fármacos , Polyporaceae/química , Sesquiterpenos/isolamento & purificação , Animais , Antinematódeos/química , Antinematódeos/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos/farmacologiaRESUMO
Two new compounds, 10-methoxydihydrofuscin (1) and fuscinarin (2), and one known compound, fuscin (3), have been isolated from the soil fungus Oidiodendron griseum. These compounds were found to compete effectively with macrophage inflammatory protein (MIP)-1 alpha for binding to human CCR5, an important anti HIV-1 target that interferes with HIV entry into cells. The structures of these compounds were elucidated by spectroscopic methods.
Assuntos
Benzopiranos/isolamento & purificação , Antagonistas dos Receptores CCR5 , Fungos/química , HIV-1/imunologia , Compostos Heterocíclicos com 3 Anéis/isolamento & purificação , Proteínas Inflamatórias de Macrófagos/metabolismo , Benzopiranos/química , Benzopiranos/farmacologia , Quimiocina CCL4 , HIV-1/fisiologia , Compostos Heterocíclicos com 3 Anéis/química , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
Two new compounds, agonodepsides A (1) and B (2), were isolated from a nonsporulating filamentous fungus, F7524. The compounds were purified via reversed-phase chromatography and their structures determined by spectroscopic methods. Agonodepside A (1) was found to inhibit the mycobacterial InhA enzyme with an IC50 value of 75 microM, while 2 was inactive at 100 microM.
Assuntos
Fungos/química , Hidroxibenzoatos/isolamento & purificação , Proteínas de Bactérias , Depsídeos , Derris/química , Hidroxibenzoatos/química , Hidroxibenzoatos/farmacologia , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , NAD/efeitos dos fármacos , Ressonância Magnética Nuclear Biomolecular , Oxirredutases/efeitos dos fármacos , Folhas de Planta/química , Plantas/químicaRESUMO
An extract from the fungus Emericella aurantiobrunnea was found to compete with macrophage inflammatory protein (MIP)-1alpha for binding to human CCR5 in a scintillation proximity assay (SPA). Bioassay-guided fractionation led to the isolation of variecolin (1) and variecolol (2), which had IC50 values of 9 and 32 microM, respectively. An X-ray crystal structure of variecolin (1) was obtained for the first time. Also isolated were four new inactive analogues, emericolin A (3), B (4), C (5), and D (6), and the relative stereochemistry of these compounds was determined by NMR methods using ROESY spectra and 1H/1H coupling constants.