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1.
J Nat Prod ; 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33216556

RESUMO

Eleven metabolites, six echinosporins (1-6), four dibenzoyls (7-10), and an aromatic compound (11), were isolated from the fermentation broth of lichen-associated Amycolatopsis hippodromi. The structures of the new compounds (1-5, 8-11) were elucidated by comprehensive spectroscopic analysis including data from experimental and calculated ECD spectra. Amycolasporins A-C (1-3) demonstrated antibacterial activities against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli with MIC values of 25 or 100 µg/mL. Amycolasporin C (3) and the known dibenzoyl (7) attenuated the production of NO due to the suppression of the expression of nitric oxide synthase (iNOS) in LPS-induced RAW 264.7 cells in a dose-dependent manner.

2.
Sci Rep ; 10(1): 5081, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193473

RESUMO

In the process of investigating the antifungal structure-activity relationships (SAR) of borrelidin and discovering antifungal leads, a semisynthetic borrelidin analogue, BN-3b with antifungal activity against Candida albicans, was achieved. In this study, we found that oxidative damage induced by endogenous reactive oxygen species (ROS) plays an important role in the antifungal activity of BN-3b. Further investigation indicated that BN-3b stimulated ROS accumulation, increased malondialdehyde (MDA) levels, and decreased reduced/oxidized glutathione (GSH/GSSG) ratio. Moreover, BN-3b decreased mitochondrial membrane potential (MMP) and ATP generation. Ultrastructure analysis revealed that BN-3b severely damaged the cell membrane of C. albicans. Quantitative PCR (RT-qPCR) analysis revealed that virulence factors of C. albicans SAPs, PLB1, PLB2, HWP1, ALSs, and LIPs were all down-regulated after BN-3b exposure. We also found that BN-3b markedly inhibited the hyphal formation of C. albicans. In addition, in vivo studies revealed that BN-3b significantly prolonged survival and decreased fungal burden in mouse model of disseminated candidiasis.

3.
Molecules ; 23(9)2018 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-30231581

RESUMO

Six new metabolites, actinofuranones D-I (compounds 1⁻6), were isolated together with three known compounds-JBIR-108 (7), E-975 (8), and E-492 (9)-from a fermentation broth of Streptomyces gramineus derived from the lichen Leptogium trichophorum. The structures of the new compounds 1⁻6 were established using comprehensive NMR spectroscopic data analysis, as well as UV, IR, and MS data. The anti-inflammatory activity of these isolated compounds were evaluated by examining their ability to inhibit nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 4, 5, 8, and 9 attenuated the production of NO due to the suppression of the expression of nitric oxide synthase (iNOS) in LPS-induced RAW 264.7 cells. Moreover, 4, 5, 8, and 9 also inhibited LPS-induced release of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α).


Assuntos
Actinobacteria/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Furanos/química , Furanos/farmacologia , Líquens/microbiologia , Actinobacteria/metabolismo , Animais , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Expressão Gênica , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Óxido Nítrico , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7
4.
Bioorg Med Chem Lett ; 28(5): 947-951, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29426772

RESUMO

A new chromanone derivative, named violacin A (1), was isolated from the fermentation broth of Streptomyces violaceoruber as a potential anti-inflammatory compound. The structure of violacin A was established using comprehensive NMR spectroscopic data analysis together with UV, IR, and MS data. The anti-inflammatory effects and action mechanisms of violacin A were investigated in vitro. The results demonstrated that violacin A attenuated the production of NO, IL-1ß, IL-6, and TNF-α as well as inhibited the expression of iNOS in LPS-induced RAW 264.7 cells. Additionally, Western blot and qRT-PCR results revealed that 1 down-regulated pro-inflammatory cytokines expression correlated with the suppression of NF-κB signaling pathway.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Ciclotídeos/farmacologia , Streptomyces/química , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/metabolismo , Ciclotídeos/biossíntese , Ciclotídeos/química , Relação Dose-Resposta a Droga , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
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