Visible‐Light‐Triggered Release of Nitric Oxide from N‐Pyramidal Nitrosamines

Abstract

Although many organic/inorganic compounds that release nitric oxide (NO) upon photoirradiation (phototriggered caged-NOs) have been reported, their photoabsorption wavelengths mostly lie in the UV region, because X-NO bonds (X=heteroatom and metal) generally have rather strong π-bond character. Thus, it is intrinsically difficult to generate organic compounds that release NO under visible light irradiation. Herein, the structures and properties of N-pyramidal nitrosamine derivatives of 7-azabicyclo[2.2.1]heptanes that release NO under visible light irradiation are described. Bathochromic shifts of the absorptions of these nitrosamines, attributed to HOMO (n)-LUMO (π*) transitions associated with the nonplanar structure of the N-NO moiety, enable the molecules to absorb visible light, which results in N-NO bond cleavage. Thus, these compounds are innate organic caged-NOs that are uncaged by visible light.

A New Lead Identification Strategy: Screening an sp3‐rich and Lead‐like Compound Library Composed of 7‐Azanorbornane Derivatives

“…[18] Furthermore, substituents can be introduced at the bridgehead positions, the methylene bridges (in this case, endo and exo isomers exist), and the 7-nitrogen atom (Figure 1), points of access which will aid in the construction of structurally divergent molecules. [19] The 7-azanorbornane skeleton is also easily accessible through the Diels-Alder reaction between an alkyne and ap yrrole. [20] In this report, we prepared as mall collection of compounds by modifying 2-ethynyl-7-azanorbornanes with click chemistry,a nd evaluated their bioactivitiesf or somem embrane-spanning receptors.…”

<i>In Cellullo</i> and <i>ex Vivo</i> Availability of a Yellowish-Green-Light-Controllable NO Releaser

“…5) Among them, lightcontrollable NO releasers are expected to be particularly useful as precisely controllable chemical tools or as agents for blood pressure regulation. [6][7][8][9][10][11] So far, several transition metalnitrosyl complexes, which contain low-energy metal-nitrosyl bonds as visible light-absorbing chromophores, have been developed as visible-light-controllable NO releasers. However, transition metal complex often shows problematic cytotoxicity after ligand release.…”

Density Functional Theory and ab Initio Computational Evidence for Nitrosamine Photoperoxides: Hammett Substituent Effects in the Photogeneration of the Nitrooxide Intermediate

“…In terms of photoreactions of nitrosamines (the subject of this study), theoretical studies in the past did not exploit Hammett substituent effects to tune their photoreactivity with molecular oxygen. Thus, we report density functional theory (DFT) and ab initio calculations, and Hammett studies on the nitrooxide intermediates formed from nitrosamine – 3 O 2 photoreactions (Figs.…”