Structural Requirements for Ga Coordination in Synthetic Analogues of the Siderophore Piscibactin Deduced by Chemical Synthesis and Density Functional Theory Calculations.

Stereoselective total synthesis of several analogues of piscibactin (Pcb), the siderophore produced by different pathogenic Gram-negative bacteria, was performed. The acid-sensitive αmethylthiazoline moiety was replaced by a more stable thiazole ring, differing in the configuration of the OH group at the C-13 position. The ability of these Pcb analogues to form complexes with Ga as a mimic of Fe showed that the configuration of the hydroxyl group at C-13 as 13 is crucial for the chelation of Ga to preserve the metal coordination, while the presence of a thiazole ring instead of the αmethylthiazoline moiety does not affect such coordination.

FrpA is the outer membrane piscibactin transporter in Vibrio anguillarum: structural elements in synthetic piscibactin analogues required for transport.

Piscibactin (Pcb) is a labile siderophore widespread among Vibrionaceae. Its production is a major virulence factor of some fish pathogens such as Photobacterium damselae subsp. piscicida and Vibrio anguillarum.

Absolute configuration by vibrational circular dichroism of anti-inflammatory macrolide briarane diterpenoids from the Gorgonian Briareum asbestinum.

The four new briarane diterpenoids 2-butyryloxybriarane B-3 (2), 9-acetylbriarenolide S (3), briarenolide W (4), and 12-isobriarenolide P (5), along with briarane B-3 (1) and the five known diterpenes 6-10 were isolated from the gorgonian coral Briareum asbestinum collected from the Mexican Caribbean Sea. The structures were elucidated by 1D and 2D NMR and MS measurements. Since the structure of briarane B-3 (1) was only suggested and published without any spectroscopic support, it was herein confirmed, and the supporting data are now provided.

The marine bivalve molluscs pathogen Vibrio neptunius produces the siderophore amphibactin, which is widespread in molluscs microbiota.

Amphiphilic siderophores, including amphibactins, are the most abundant siderophores in oceans. Genes putatively encoding the amphibactin system were proposed in some bacteria and homologues of these genes are particularly abundant in multiple bacterial lineages inhabitant of low-iron seawater. However, since no defective mutant strains in any of these genes were studied to date, their role in amphibactin synthesis or uptake was not demonstrated.

Synthesis of Functionalized Magnetic Nanoparticles, Their Conjugation with the Siderophore Feroxamine and its Evaluation for Bacteria Detection.

In the present work, the synthesis of magnetic nanoparticles, its coating with SiO2, followed by its amine functionalization with (3-aminopropyl)triethoxysilane (APTES) and its conjugation with deferoxamine, a siderophore recognized by Yersinia enterocolitica, using a succinyl moiety as a linker are described. Magnetic nanoparticles (MNP) of magnetite (Fe3O4) were prepared by solvothermal method and coated with SiO2 (MNP@SiO2) using the Stöber process followed by functionalization with APTES (MNP@SiO2@NH2). Then, feroxamine was conjugated with the MNP@SiO2@NH2 by carbodiimide coupling to give MNP@SiO2@NH2@Fa.

Preparation of functionalized magnetic nanoparticles conjugated with feroxamine and their evaluation for pathogen detection.

This work reports the preparation of a conjugate between amino-functionalized silica magnetite and the siderophore feroxamine. The morphology and properties of the conjugate and intermediate magnetic nanoparticles (MNPs) were examined by powder X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), magnetization studies, zeta potential measurements, Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) mapping. Furthermore, this study investigated the interaction between the functionalized magnetic NPs and wild type (WC-A) using Scanning Electron Microscopy (SEM) and TEM images.

The Siderophore Piscibactin Is a Relevant Virulence Factor for Favored at Low Temperatures.

causes vibriosis, a hemorrhagic septicaemia that affects many cultured marine fish species worldwide. Two catechol siderophores, vanchrobactin and anguibactin, were previously identified in this bacterium. While vanchrobactin is a chromosomally encoded system widespread in all pathogenic and environmental strains, anguibactin is a plasmid-encoded system restricted to serotype O1 strains.

Peruvioses A to F, sucrose esters from the exudate of Physalis peruviana fruit as α-amylase inhibitors.

The fruit of Physalis peruviana is widely used in traditional Colombian medicine as an antidiabetic treatment. The aim of the study reported here was to identify the compounds responsible for the hypoglycemic activity using the α-amylase inhibition test. Bioguided fractionation of a dichloromethane extract of the sticky exudate that covers the fruit allowed the isolation and identification of three new sucrose esters, named as peruvioses C-E (1-3), along with the known peruvioses A (6), B (5) and F (4), the structures of which were elucidated by extensive NMR and MS experiments.