HNO Generates Unique Chemical Markers

The first reaction of nitroxyl (HNO) with organic phosphines has been achieved, yielding unique HNO-based amide products that can be used to detect HNO in biological systems (Org. Lett., DOI: 10.1021/ol900914s). HNO, the reduced protonated form of the biological signaling agent nitric oxide, promotes heart contractions and is therefore considered to be the basis for potential congestive heart failure medications. But "the lack of specific HNO detection methods has impeded the understanding of HNO in biological systems," write S. Bruce King and coworkers of Wake Forest University. They report that HNO reacts with triarylphosphines to produce reactive aza-ylides, which then react immediately with a neighboring ester group to generate stable and unique amide products. The amides can thus be used as markers for HNO in biological systems. According to the researchers, these experiments document the reactivity of HNO with triarylphosphines and provide insight into a new method for distinguishing this important biologically active nitrogen oxide.