One-step Bio-guided Isolation of Secondary Metabolites from the Endophytic Fungus crustosum Using High-resolution Semi-preparative HPLC.

Background: An endophytic fungal strain was isolated from the seagrass and investigated to identify its antimicrobial constituents and characterize its metabolome composition. The ethyl acetate extract of this fungus exhibited antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) as well as an anti-quorum sensing effect against .

Methods: The crude extract was profiled by UHPLC-HRMS/MS, and the dereplication was assisted by feature-based molecular networking.

A Zur-mediated transcriptional regulation of the zinc export system in Pseudomonas aeruginosa.

The control of cellular zinc (Zn) concentrations by dedicated import and export systems is essential for the survival and virulence of Pseudomonas aeruginosa. The transcription of its many Zn transporters is therefore tightly regulated by a known set of transcription factors involved in either the import or the export of Zn. In this work, we show that the Zur protein, a well-known repressor of Zn import, plays a dual role and functions in both import and export processes.

Combination of Pseudo-LC-NMR and HRMS/MS-Based Molecular Networking for the Rapid Identification of Antimicrobial Metabolites From .

An endophytic fungal strain isolated from a seagrass endemic to the Mediterranean Sea () was studied in order to identify its antimicrobial constituents and further characterize the composition of its metabolome. It was identified as by in-depth phylogenetic analyses. The ethyl acetate extract of that strain exhibited antimicrobial activities and an ability to inhibit quorum sensing of .

Global Analysis of the Zinc Homeostasis Network in and Its Gene Expression Dynamics.

Zinc is one of the most important trace elements for life and its deficiency, like its excess, can be fatal. In the bacterial opportunistic pathogen , Zn homeostasis is not only required for survival, but also for virulence and antibiotic resistance. Thus, the bacterium possesses multiple Zn import/export/storage systems.

Characterization of Quorum Sensing Inhibitors from the Endophyte and Evaluation of Their Antivirulence Effects by Metabolomics.

The opportunistic pathogen is one of the "critical priority pathogens" due to its multidrug resistance to a wide range of antibiotics. Its ability to invade and damage host tissues is due to the use of quorum sensing (QS) to collectively produce a plethora of virulence factors. Inhibition of QS is an attractive strategy for new antimicrobial agents because it disrupts the initial events of infection without killing the pathogen.

Isolation and Identification of Isocoumarin Derivatives With Specific Inhibitory Activity Against Wnt Pathway and Metabolome Characterization of .

The Wnt signaling pathway controls multiple events during embryonic development of multicellular animals and is carcinogenic when aberrantly activated in adults. Breast cancers are dependent on Wnt pathway overactivation mostly through dysregulation of pathway component protein expression, which necessitates the search for therapeutically relevant compounds targeting them. Highly diverse microorganisms as endophytes represent an underexplored field in the therapeutic natural products research.

Stereoselective synthesis of 2-spirocyclopropyl-indolin-3-ones through cyclopropanation of aza-aurones with tosylhydrazones.

A simple and efficient approach for the synthesis of 2-spirocyclopropyl-indolin-3-ones is herein described. The method involves a diasteroselective cyclopropanation of aza-aurones with tosylhydrazones, selected as versatile carbene sources, and represents a remarkable synthetic alternative to get access to this class of C2-spiropseudoindoxyl scaffolds. The reactions proceed in the presence of a base and catalytic amounts of benzyl triethylammonium chloride and well-tolerate a broad range of substituents on both aza-aurones and tosylhydrazones to afford a series of C2-spirocyclopropanated derivatives in high yields.

The CzcCBA Efflux System Requires the CadA P-Type ATPase for Timely Expression Upon Zinc Excess in .

Zinc (Zn) is a trace element essential for life but can be toxic if present in excess. While cells have import systems to guarantee a vital Zn intracellular concentration, they also rely on export systems to avoid lethal Zn overload. In particular, the opportunistic pathogen possesses four Zn export systems: CadA, CzcCBA, CzcD, and YiiP.

Transcriptome Analysis of Cultured in Human Burn Wound Exudates.

is a severe opportunistic pathogen and is one of the major causes of hard to treat burn wound infections. Herein we have used an RNA-seq transcriptomic approach to study the behavior of PAO1 growing directly on human burn wound exudate. A chemical analysis of compounds used by this bacterium, coupled with kinetics expression of central genes has allowed us to obtain a global view of physiological and metabolic changes occurring while growing on human burn wound exudate.

Pseudomonas aeruginosa zinc homeostasis: Key issues for an opportunistic pathogen.

Zinc is an essential trace element for almost all living organisms. In the opportunistic bacterial pathogen Pseudomonas aeruginosa, zinc has been shown to play an important role in virulence, in colonization of the host organism and has also been shown to be involved in antibiotic resistance. P.