Rice blast caused by Pyricularia oryzae, which is a major threat to food security worldwide, markedly decreases the yield of rice. Some rhizobacteria called 'plant growth-promoting rhizobacteria' inhibit plant pathogens and improve growth secreting iron-chelating siderophores. The decreased availability iron adversely affects survival pathogens, especially fungal in rhizosphere. This study aime...

Analogs of chloramphenicol were prepared for the first time in which the nitro group was replaced by hydroxylamine, nitroso, hydroxamic acid, methyl hydroxamate, and O-acetyl hydroxamate functional groups. These compounds were tested for antibiotic activity in order to determine whether the antibiotic activity of chloramphenicol is mediated by one or more of these potential metabolites of chlor...

From our experimental evidence that iron lirnitation greatly increases the extracellular concentration of strong copper-complexing agents in cultures of Anabaena flos-aquae and Anabaena cyhdrica, and that the iron-algal exudate complex is much more stable than the copper complex, we conclude that strong copper-complexing agents released by filamentous blue-green algae are siderophores. Further ...

Thirtyfive siderophore producing fungi were categorized for their hydroxamate, catecholate or carboxylate nature by chemical and bioassays. Out of 35 fungi, 30 were hydroxamates and 5 showed carboxylate nature. However, none of the fungi produced catecholate type of siderophores. Eighteen out of 29 fungi were trihydroxamate and the rest 11 fungi were dihydroxamates. Twenty-three fungi were hexa...

The limitation of hydroxamate ester as a chiral Lewis acid coordination moiety was first shown in an intermolecular reaction involving a radical addition and sequential allylation processes. Next, the effect of hydroxamate ester was studied in the cascade addition-cyclization-trapping reaction of substrates with a carbon-carbon triple bond as a radical acceptor. When substrates with a methacryl...

The zoopathogenic fungus Histoplasma capsulatum, like other eukaryotic aerobic microorganisms, requires iron for growth. Under conditions of low iron availability, the fungus secretes hydroxamates that function as siderophores (iron chelators). The experiments to be reported were designed to gather further information on the hydroxamate siderophores of H. capsulatum. The fungus was grown in a s...

Abstract Microorganisms adopt a unique mechanism for sequestration and transport of bound iron by producing iron-chelating molecules called siderophores. Siderophores play an important role in colonization microbes iron-deficient sites the host, hence acting as virulence factor promising carriers antimicrobials to target inside microbial cells. The research was conducted identify characterize s...

An assay to detect UO(2)(2+) complexation was developed based on the chrome azurol S (CAS) assay for siderophores (B. Schwyn and J. B. Neilands, Anal. Biochem. 160:47-56, 1987) and was used to investigate the ability of fungal metabolites to complex actinides. In this assay the discoloration of two dyed agars (one containing a CAS-Fe(3+) dye and the other containing a CAS-UO(2)(2+) dye) caused ...