RESUMO
A new prenylated indole alkaloid, named paraherquamide J (1), together with four known compounds (2-5), were isolated from the mangrove rhizosphere soil-derived fungus Penicillium janthinellum HK1-6. The planar structure and relative configuration of 1 were determined by detailed analysis of the spectroscopic data especially the NOESY spectrum. The absolute configuration of 1 was determined by ECD spectra. Compound 2 was first isolated as a natural product and named as paraherquamide K. All isolated metabolites were evaluated for their antibacterial, topoisomerase I (topo I) inhibitory activities and lethality towards brine shrimp Artemia salina.
Assuntos
Antibacterianos/isolamento & purificação , Indolizinas/isolamento & purificação , Penicillium/química , Compostos de Espiro/isolamento & purificação , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Artemia/efeitos dos fármacos , Alcaloides Indólicos/química , Alcaloides Indólicos/isolamento & purificação , Alcaloides Indólicos/farmacologia , Indolizinas/toxicidade , Estrutura Molecular , Prenilação , Rizosfera , Compostos de Espiro/toxicidade , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/isolamento & purificação , Inibidores da Topoisomerase I/farmacologiaRESUMO
Two new unsaturated fatty acids, 6R,8R-dihydroxy-9Z,12Z-octadecadienoic acid (1) and methyl-6R,8R-dihydroxy-9Z,12Z-octadecadienoate (2), and two known 9Z,12Z-octadecadienoic acid analogues (3, 4) together with a known sesquiterpenoid (5) were isolated from the mangrove rhizosphere soil-derived fungus Penicillium javanicum HK1-22. An acetonide derivative (1a) from 1 was also prepared. The relative configuration of 1 was determined by analysis of the 1D and 2D NOE spectra of 1a. The absolute configuration of 1 was assigned on the basis of biogenetic considerations. The antifungal activity of the high yield compound 5 was evaluated against four strains of crop pathogens and it showed significant antifungal activities against all the tested strains.
Assuntos
Ácidos Graxos Insaturados/isolamento & purificação , Penicillium/química , Rizosfera , Microbiologia do Solo , Áreas Alagadas , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Produtos Agrícolas/microbiologia , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/farmacologia , Penicillium/classificação , Penicillium/genética , Filogenia , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Three novel monomeric naphtho-γ-pyrones, peninaphones A-C (compounds 1-3), along with two known bis-naphtho-γ-pyrones (compounds 4 and 5) were isolated from mangrove rhizosphere soil-derived fungus Penicillium sp. HK1-22. The absolute configurations of compounds 1 and 2 were determined by electronic circular dichroism (ECD) spectra, and the structure of compound 3 was confirmed by single-crystal X-ray diffraction analysis. Compounds 4 and 5 are a pair of hindered rotation isomers. A hypothetical biosynthetic pathway for the isolated monomeric and dimeric naphtho-γ-pyrones is also discussed in this study. Compounds 1-3 showed antibacterial activity against Staphylococcus aureus (ATCC 43300, 33591, 29213, and 25923) with minimum inhibitory concentration (MIC) values in the range of 12.5-50 µg/mL. Compound 3 exhibited significant activity against the rice sheath blight pathogen Rhizoctonia solani.
Assuntos
Organismos Aquáticos/química , Basidiomycota/efeitos dos fármacos , Penicillium/química , Pironas/química , Pironas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Dicroísmo Circular , Testes de Sensibilidade Microbiana , Estrutura Molecular , Difração de Raios XRESUMO
Cultivation of the mangrove rhizosphere soil-derived fungus Penicillium janthinellum HK1-6 with NaBr led to the isolation of two new brominated azaphilones, penicilones G and H (5, 6), two new tricyclic polyketides, penijanthinones A and B (7, 8), and two known azaphilones, penicilones A and B (1, 2). The planar structures and relative configurations of the new compounds were elucidated using comprehensive spectroscopic methods including 1D and 2D NOE spectra. Their absolute configurations were determined by chemical conversions, TDDFT ECD calculations, and comparisons of their ECD spectra. Interestingly, the NaBr-induced brominated azaphilones (5, 6) had the opposite configuration at C-7 compared to the chloro analogues (3, 4) produced by this fungus cultivated with sea salt. Ester hydrolysis of penicilone B (2) afforded the carboxylic acid side chain 2,4-dimethyldec-2-enoic acid (9), with a 4 S configuration assigned by its specific rotation. Penicilone H (6) showed antibacterial activity with MIC values ranging from 3.13 to 12.5 µg/mL.
Assuntos
Benzopiranos/metabolismo , Penicillium/metabolismo , Policetídeos/metabolismo , Microbiologia do Solo , Benzopiranos/química , Benzopiranos/farmacologia , Brometos/farmacologia , Linhagem Celular Tumoral , Halogenação , Humanos , Espectroscopia de Ressonância Magnética , Policetídeos/química , Policetídeos/farmacologia , Compostos de Sódio/farmacologiaRESUMO
Four new azaphilones, penicilones A-D (1-4), were isolated from the mangrove rhizosphere soil-derived fungus Penicillium janthinellum HK1-6. Their planar structures and absolute configurations were determined by extensive analysis of NMR spectroscopic data, ECD spectra, the modified Mosher's method, and chemical conversions. Interestingly, 1 and 2 had the opposite configuration at C-7 compared to the closely related chloro analogues 3 and 4. Ester hydrolysis of 2 and 4 afforded their parental azaphilones, named penicilones E (5) and F (6). Compounds 1-6 were evaluated for their antibacterial activities in vitro. Penicilones B-D (2-4) showed potent anti-MRSA (Staphylococcus aureus ATCC 43300, ATCC 33591) activities with MIC values ranging from 3.13 to 6.25 µg/mL.
