Aminooxybearing

Aminooxybearing is a descriptor used in organic and bioconjugation chemistry to refer to molecules that carry at least one aminooxy functional group. The aminooxy group is characterized by an oxygen-amine bond (-O-NH2) that is commonly appended to a carbon skeleton through an ether linkage. In practice, aminooxybearing compounds include derivatives in which the ONH2 moiety is linked directly to carbon or through a linker such as an alkyl chain or benzyl spacer. The term covers simple small molecules (for example, aminooxyacetic acid, where the moiety is –O–NH2 attached to an acetic backbone) as well as more complex bioconjugation reagents.

Reactivity and properties: The aminooxy group is a nucleophilic nitrogen that reacts readily with aldehydes and ketones to form oximes. This oxime ligation proceeds under mild, aqueous conditions and is widely used for labeling, immobilization, and glycan tagging. The chemistry is valued for chemoselectivity and biocompatibility, particularly in the context of biomolecules such as proteins and sugars. Aminooxybearing substrates may vary in stability depending on the surrounding functional groups and the pH.

Applications: The central use of aminooxybearing compounds is in oxime-based bioconjugation, including glycoprotein labeling, synthesis of crosslinks, and the development of affinity tags. They are also employed in materials science and medicinal chemistry as reactive handles for functionalization.

See also: aminooxy group, oxime ligation, glycan labeling.

Note: The term is most common in specialized literature and patent literature; it is not a formal class in many chemical databases.