Quantitative generation of singlet (1Δg) oxygen from acidified aqueous peroxynitrite produced by the reaction of nitric oxide and superoxide anion
✍ Scribed by Khan, Ahsan Ullah
- Publisher
- John Wiley and Sons
- Year
- 1995
- Weight
- 355 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0884-3996
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✦ Synopsis
Simple acidification o f aqueous alkaline peroxynitrite quantitatively generates singlet ('Ag) molecular oxygen, detected and quantitated spectroscopically (1 270 nm). This observation provides a chemical basis for physiological cytotoxicity o f ONOO-generated i n the diffusioncontrolled reaction o f cellular NO' and 0;. The experiments consist of (i) chemical generation o f ONOO-from NO' gas and KO2 powder in alkaline aqueous solution; (ii) absorption spectral identification o f ONOOin the near-UV w i t h maximum at 302nm; (iii) spectroscopic identification o f '02 by its emission band a t 1200-1 340 n m with maximum at 1275 nm; and (iv) quantitation of ' O2 generated in ONOO-/H+ reaction by comparison o f the chemiluminescence intensity at 1270 n m w i t h that from H2O2/OCI-reaction that generates '02 with unit efficiency a t alkaline pH. ' 0 2 was generated w i t h unit efficiency with respect t o ONOOconcentration by the ONOO-/H+ reaction.