Is azanone endogenously produced in mammals?

Abstract

A key question related to HNO and its biological role, concerns the possibility of endogenous formation. In this chapter we present an overview of the various proposed pathways to HNO endogenous synthesis including supporting evidence. We first present enzymatic routes, such as incomplete oxidation of arginine by nitric oxide synthase, heme protein mediated oxidation of hydroxylamine, and NO reduction by superoxide dismutase and xanthine oxidase, with focus on mechanistic aspects related to protein structure. We then describe the proposed spontaneous pathways to HNO, such as NO reaction with sulfenic acid and aromatic alcohols. Finally, we conclude with a discussion of the physiological impact of HNO biosynthesis.