Hydroxyl radical generation via photoreduction of a simple pyridine N-oxide by an NADH analogue.

Photoreduction of pyridine N-oxide, which has a key structure of antitumor agents for hypoxic solid tumors, by 1-benzyl-1,4-dihydronicotinamide in deaerated aprotic media resulted in generation of hydroxyl radical, leading to the oxidation of salicylic acid to 2,3- and 2,5-dihydroxybenzoic acids, and catechol.

[NO-release ability and DNA-damage activity of aromatic N-nitroso compounds].

To develop a new nitric oxide-donor (NO-donor) that is useful for chemical and biochemical research, we synthesized several aromatic N-nitroso compounds including 1-[N-nitroso-N-(4-tolyl)carbamoyl] piperidine-4-carboxylic acid (1f) and phenyl(2-pyridyl)-N-nitrosamines, which spontaneously generate NO at ambient temperature. Thermal decomposition of these compounds was run under mild conditions. Gaseous NO released from them was quantified by means of the Griess reaction using a specially designed apparatus in which NO2- is generated from NO.