depmpo

DEPMPO is a phosphorylated derivative of the widely used DMPO spin trap. It has been reported to produce spin adducts with increased stability particularly for the adduct of superoxide. [1] [2] [3] DEPMPO displays a detectable spin adduct signal at a concentration as low as 1 mM, as compared to 5 mM for DMPO.[3] A significant advantage of using DEPMPO in trapping superoxide radical is that the decomposition of DEPMPO/O2 - does not produce the OH adduct, which can be a drawback when using DMPO. [2][3]

DEPMPO is a nitrone that is used to spin trap reactive O-, N-, S-, and C-centered radicals and allow their characterization when used in association with electron spin resonance. It is noted for the stability of adducts formed. DEPMPO can be used in vitro or in vivo, as it crosses lipid bilayer membranes and is a good trapping agent in biological systems. DEPMPO-biotin is a biotinylated form of DEPMPO which retains the outstanding persistency of its adducts. The biotin moiety offers an effective means for monitoring biodistribution in cells, tissues, and organs when used with an avidin-conjugated reporter. Importantly, DEPMPO-biotin binds free radicals, such as S-nitroso groups, on proteins, producing adducts that can be analyzed via the biotin tag. This direct labeling of S-nitrosothiols (SNO) thus serves as an effective alternative to the more cumbersome biotin-switch method for monitoring SNO formation.

CYPMPO is a free radical spin trap with excellent trapping capabilities toward hydroxyl and superoxide radicals in biological and chemical systems. Decay of the superoxide adduct of CYPMPO proceeds in an apparent first order fashion with half-lives of 15 and 51 minutes in a UV-illuminated hydrogen peroxide solution and a hypoxanthine/xanthine oxidase system, respectively. CYPMPO traps superoxide radicals generated by bovine neutrophils as effectively as DEPMPO.[1] The high melting point (126°C), low hygroscopic properties, and long shelf-life in aqueous solutions offer significant practical advantages for use of CYPMPO over DEPMPO and DMPO.