RESUMO
Brasiliamides are a class of piperazine-containing alkaloids produced by Penicillium brasilianum with a range of pharmaceutical activities. The mechanism of brasiliamide biosynthesis, including piperazine ring formation and multiple tailoring modifications, still remains unclear. In this study, the biosynthetic gene cluster of brasiliamides, brs, was identified from the marine-derived fungal strain Penicillium brasilianum WZXY-M122-9. Deletion of a histone deacetylase-encoding gene using a CRISPR/Cas9 gene editing system led to the production of a new compound, namely brasiliamide I (1). The brs-encoded single-module nonribosomal peptide synthetase (NRPS) BrsA is involved in the formation of the piperazine skeleton of brasiliamides. Full-length BrsA protein (113.6 kDa) was purified, and reconstitution of enzymatic activity in vitro confirmed that BrsA stereoselectively accepts L-phenylalanine as the substrate. Multiple deletion of tailoring genes and analysis of purified proteins in vitro enabled us to propose a brasiliamide biosynthetic pathway. In the tailoring steps, an α-ketoglutarate (KG)-dependent nonheme iron dioxygenase, BrsJ, was identified to catalyze piperazine ring cleavage during biosynthesis of brasiliamide A (2). KEY POINTS: The gene cluster encoding brasiliamide biosynthesis, brs, is identified. Deletion of a histone deacetylase-encoding gene produces brasiliamide I. BrsA catalyzes brasiliamide piperazine skeleton formation. BrsJ catalyzes piperazine ring cleavage to produce brasiliamide A. Graphical abstract.
Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Dioxóis/metabolismo , Proteínas Fúngicas/metabolismo , Peptídeo Sintases/metabolismo , Piperazina/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Vias Biossintéticas/genética , Catálise , Dioxóis/química , Dioxóis/isolamento & purificação , Proteínas Fúngicas/genética , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Estrutura Molecular , Família Multigênica , Mutação , Penicillium/genética , Penicillium/metabolismo , Peptídeo Sintases/genética , Piperazina/química , Piperazina/isolamento & purificaçãoRESUMO
A new xanthoquinodin B9 (1), together with two known xanthoquinodins, xanthoquinodin A1 (2) and xanthoquinodin A3 (3), three epipolythiodioxopiperazines, chetomin (4), chaetocochin C (5) and dethio-tetra(methylthio)chetomin (6), and four other compounds, chrysophanol (7), emodin (8), alatinone (9), and ergosterol (10) were isolated from the endophytic fungus Chaetomium globosum 7s-1, isolated from Rhapis cochinchinensis (Lour.) Mart. All isolated structures were established based on their spectroscopic data analyses. Compounds 1-6 showed antibacterial activity against Gram positive bacteria with MICs ranging from 0.02 pM to 10.81 µM. Compounds 1-6 also exhibited cytotoxicity against KB, MCF-7 and NCI-H187 cancer cell lines (IC50 0.04-18.40 µM). However, they were cytotoxic towards a normal cell line (Vero cell) with IC50 values ranging from 0.04 to 3.86 µM.
Assuntos
Antibacterianos/isolamento & purificação , Antineoplásicos/isolamento & purificação , Chaetomium/química , Cromonas/isolamento & purificação , Citotoxinas/isolamento & purificação , Piperazina/isolamento & purificação , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Cromonas/química , Citotoxinas/química , Citotoxinas/farmacologia , Dissulfetos/isolamento & purificação , Ergosterol/química , Ergosterol/isolamento & purificação , Humanos , Alcaloides Indólicos/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piperazina/química , Piperazinas/isolamento & purificação , Células VeroRESUMO
Seven known echinulin-related indolediketopiperazine alkaloids (1-7) were isolated from the Vietnamese sediment-derived fungus Aspergillus niveoglaucus. Using chiral HPLC, the enantiomers of cryptoechinuline B (1) were isolated as individual compounds for the first time. (+)-Cryptoechinuline B (1a) exhibited neuroprotective activity in 6-OHDA-, paraquat-, and rotenone-induced in vitro models of Parkinson's disease. (-)-Cryptoechinuline B (1b) and neoechinulin C (5) protected the neuronal cells against paraquat-induced damage in a Parkinson's disease model. Neoechinulin B (4) exhibited cytoprotective activity in a rotenone-induced model, and neoechinulin (7) showed activity in the 6-OHDA-induced model.
Assuntos
Alcaloides/farmacologia , Aspergillus/química , Fármacos Neuroprotetores/farmacologia , Piperazina/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Humanos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/isolamento & purificação , Paraquat/toxicidade , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/tratamento farmacológico , Piperazina/análogos & derivados , Piperazina/química , Piperazina/isolamento & purificaçãoRESUMO
Two new piperazine-triones lansai E and F (1, 2), together with four known secondary metabolites lansai D (3), 1-N-methyl-(E,Z)-albonoursin (4), imidazo[4,5-e]-1,2,4-triazine (5), and streptonigrin (6) were isolated from a deep-sea-derived Streptomycetes sp. strain SMS636. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compound 4 exhibited moderate antibacterial activities against Staphylococcus aureus and methicillin resistant S. aureus (MRSA) with Minimum Inhibitory Concentration (MIC) values of 12.5 and 25 µg/mL, respectively. Compound 6 displayed significant antibacterial activities against S. aureus, MRSA and Bacillus Calmette-Guérin (BCG) with MIC values of 0.78, 0.78 and 1.25 µg/mL, respectively.
