Siderophores (ferric ion chelators) are secreted by organisms in response to iron deficiency. The pathogenic enterobacterium Erwinia chrysanthemi produces two siderophores, achromobactin and chrysobactin (CB), which are required for systemic dissemination in host plants. Previous studies have shown that CB is produced in planta and can trigger the up-regulation of the plant ferritin gene AtFER1...

Salvadora persica (Salvadoraceae) is widely used in Unani system of medicine. Its root and stem were extracted using solvents of different polarities and explored for in-vitro free radical scavenging activity and lipid per-oxidation assay in rat brain homogenate. Preliminary assays of six different extracts of Salvadora persica, scavenges 1,1diphenyl-2-picrylhydrazyl stable free radicals in con...

In the present in vitro study, the effects of pH and ionic strength on the release of iron from pectin and the ability of pectin to reduce ferric iron to ferrous iron were examined. The bioavailability of Fe bound to pectin was evaluated in rats. The amount of Fe released from pectin was at a maximum at pH 2·0 and decreased as the pH value increased. At pH 2·0, the amount of Fe released from pe...

Vibrio vulnificus is a causative agent of serious food-borne diseases in humans related to consumption of raw seafoods. This human pathogen secretes a metalloprotease (VVP) that evokes enhancement of the vascular permeability and disruption of the capillaries. Production of microbial proteases is generally induced at early stationary phase of its growth. This cell density dependent regulation o...

Of the different growth supplements used in chemically defined media, only transferrin is required for differentiation of tubules in the embryonic mouse metanephros. Since transferrin is an iron-carrying protein, we asked whether iron is crucial for tubulogenesis. Differentiation of metanephric tubules both in whole embryonic kidneys and in a transfilter system was studied. The tissues were gro...

Fe(III) oxides hydrated to various extents are the most abundant iron species in soil. Their extremely low solubility makes them almost unavailable to living organisms. To cope with iron deficiency, many microorganisms synthesize and secrete siderophores [1–5], which are low-molecular-weight compounds that specifically chelate Fe(III) to form stable complexes, into the soil (association constan...

The formation of blue coloured ferric anthocyanin chelates and their colour stability during storage and thermal treatment were monitored in a pH range relevant to food (3.6-5.0). Liquid model systems were composed of different types of Citrus pectins, juices (J) and the respective phenolic extracts (E) from elderberry (EB), black currant (BC), red cabbage (RC) and purple carrot (PC) in the pre...

Previous studies have shown that there is a major difference between the iron release mechanism of enterobactin, a catechol-based siderophore, and that of the hydroxamate-based siderophores such as ferrichrome. For ferric enterobactin there is an esterase that hydrolyzes the ligand during iron release. In contrast, iron is released by the hydroxamate-based siderophores and the ligands are reuse...