A siderophore, named bisucaberin B, was isolated from Tenacibaculum mesophilum bacteria separated from a marine sponge collected in the Republic of Palau. Using spectroscopic and chemical methods, the structure of bisucaberin B (1) was clearly determined to be a linear dimeric hydroxamate class siderophore. Although compound 1 is an open form of the known macrocyclic dimer bisucaberin (2), and ...

A series of pyrazolo[3,4-d]pyrimidine derivatives was synthesized and evaluated for the Src kinase inhibitory activities. Compound 6e and 10c exhibited inhibition of Src kinase with an IC50 value of 5.6 and 5.1 μM, respectively. Hydroxamate derivative 15a was found to be a metal-mediated inhibitor for human Csk with an IC50 value of 2.0 μM showing 56-fold selectivity over Src kinase inhibition.

1. Glutamine synthetase activity has been determined in extracts of rat cardiac and skeletal muscle and kidney, after treatment to ensure that the rate of synthesis was proportional to time of incubation and to amount of extract added. The activity was measured by two methods, with hydroxylamine as substrate. 2. No activity was detected in rat heart extract by either method. The activity in ske...

Siderophores are divided to 2 main structural groups: hydroxamates and catecholates (Drechsel et al. 1995). Hydroxamate siderophores are produced both by bacteria and fungi, while catecholates are reported to the produced only by bacteria (Messenger and Ratledge, 1985). A third group of siderophores the carboxylate (= complexone) type has been reported to be produced exclusively by fungi belong...

Microbial iron transport compounds, belonging either to the hydroxamate family excreted by pseudomonads, or to the phenolate family excreted by salmonellae, reverse the bacteriostatic effect of conalbumin on the growth of these bacteria in egg white. The presence of microgram quantities of these compounds permits both salmonellae and pseudomonads to reach dense populations in egg white. The rol...

The biochemical and molecular mechanisms used by alkaliphilic bacteria to acquire iron are unknown. We demonstrate that alkaliphilic (pH > 9) Bacillus species are sensitive to artificial iron (Fe³+) chelators and produce iron-chelating molecules. These alkaliphilic siderophores contain catechol and hydroxamate moieties, and their synthesis is stimulated by manganese(II) salts and suppressed by ...

The swine pathogen Actinobacillus pleuropneumoniae possesses a 75-kDa outer membrane protein (OMP), FhuA, the receptor for ferrichrome, a hydroxamate-type siderophore. Polyclonal serum to FhuA reacted with OMP preparations from 12 serotypes of A. pleuropneumoniae under conditions of iron repletion and restriction. Reverse transcription-PCR confirmed that A. pleuropneumoniae fhuA expression is n...