Hydroxamic Acid: An Underrated Moiety? Marrying Bioinorganic Chemistry and Polymer Science

Abstract

Even 150 years after their discovery, hydroxamic acids are mainly known as the starting material for the Lossen rearrangement in textbooks. However, hydroxamic acids feature a plethora of existing and potential applications ranging from medical purposes to materials science, based on their excellent complexation properties. This underrated functional moiety can undergo a broad variety of organic transformations and possesses unique coordination properties for a large variety of metal ions, for example, Fe­(III), Zn­(II), Mn­(II), and Cr­(III). This renders it ideal for biomedical applications in the field of metal-associated diseases or the inhibition of metalloenzymes, as well as for the separation of metals. Considering their chemical stability and reactivity, their biological origin and both medical and industrial applications, this Perspective aims at highlighting hydroxamic acids as highly promising chelators in the fields of both medical and materials science. Furthermore, the state of the art in combining hydroxamic acids with a variety of polymer structures is discussed and a perspective regarding their vast potential at the interface of bioinorganic and polymer chemistry is given.

The Race for Hydroxamate-Based Zirconium-89 Chelators

“…They provide excellent complexation properties for a large variety of metal ions, such as Fe 3+ , Mn 2+ and Zr 4+ . Each hydroxamate group binds to the metal in a bidentate fashion via O,Ocoordination to form stable five-membered ring structures (Figure 1) [24]. The only chelator used to date in the clinic to complex 89 Zr for immunoPET is desferrioxamine (deferoxamine, DFO, Figure 3a).…”

Functional Gels Containing Hydroxamic Acid Degrade Organophosphates in Aqueous Solutions

“…We modify poly­(maleic anhydride-co-methyl vinyl ether) copolymers chemically with hydroxylamine to obtain hydroxamic acids, which are active in degrading organophosphates . The moiety also has other applications, such as in the biochemistry of metals . Self-supporting gels made of such polymers give these systems a unique ability of direct contact with contaminated stream to produce a purified effluent, while still maintaining structural integrity (cf.…”

“…38 The moiety also has other applications, such as in the biochemistry of metals. 39 Self-supporting gels made of such polymers give these systems a unique ability of direct contact with contaminated stream to produce a purified effluent, while still maintaining structural integrity (cf. Figure 1a).…”

Silica Xerogel Doped with Iron(III) as Sensor Material for Salicylhydroxamic Acid Determination in Urine

“…Hydroxamic acids (HA) are well-known for their outstanding complexation properties: complexes with 19 metals are known. The most prominent complexes are formed with iron(III) and they are also often found in nature to increase the bioavailability of insoluble iron compounds [ 1 ].…”

“…Three HA—salicylhydroxamic acid (SHA), suberanilohydroxamic acid (SAHA), and deferoxamine (DFA)—are already commonly used in medicine [ 1 , 4 , 5 ]. However, these medications have been linked with various acute and chronic side effects [ 6 ].…”