The general structure of a hydroxamic acid

A hydroxamic acid is a class of chemical compounds sharing the same functional group in which an amine is inserted into an carboxylic acid. A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. Carboxylic acids are Organic acids characterized by the presence of a Carboxyl group, which has the formula -C(=OOH usually written -COOH or -CO2H Its general structure is R-CO-NH-OH, with an R as an organic residue, a CO as a carbonyl group, and a hydroxylamine as NH₂-OH. In Organic chemistry, a carbonyl group is a Functional group composed of a Carbon Atom double-bonded to an Oxygen Hydroxylamine is a reactive chemical with formula NH2OH It can be considered a hybrid of Ammonia and Water due to parallels it shares They are used as metal chelators. Chelation is the binding or complexation of a bi- or multidentate Ligand.

Hydroxamic acids can be synthesized from aldehydes via the Angeli-Rimini reaction. The Angeli-Rimini reaction is an Organic reaction between an Aldehyde and the sulfonamide N-hydroxybenzenesulfonamide in presence of base A well-known hydroxamic acid reaction is the Lossen rearrangement. The Lossen rearrangement is the Chemical reaction of a Hydroxamic acid 1 with a dehydration agent (such as Tosyl chloride) to form the O-derivative

Hydroxamates are essential growth factors, or vitamins, for some microbes. They function as iron-binding compounds (siderophores) that solubilise iron and transport it into the cell.

Iron is a key component of cytochromes and iron-sulphur proteins (involved in electron transport) and is thus important in cellular respiration. In an environment, absent from oxygen (anoxic); iron will be present in the ferrous +2 oxidation state (Fe²⁺), which is water-soluble. Under oxic conditions; iron will be in the ferric +3 oxidation state (Fe³⁺), in insoluble mineral form. The powerful chelating properties of hydroxamic acid and its derivatives is exploited by bacteria to obtain ferric iron. Once the iron-hydroxamate complex has entered the cell, the iron is liberated and the hydroxamic acid can be excreted and reused for iron transport.