Determination of residual manganese in Mn porphyrin-based superoxide dismutase (SOD) and peroxynitrite reductase mimics.
Journal Article (Journal Article)
The awareness of the beneficial effects of Mn porphyrin-based superoxide dismutase (SOD) mimics and peroxynitrite scavengers on decreasing oxidative stress injuries has increased the use of these compounds as mechanistic probes and potential therapeutics. Simple Mn2+ salts, however, have SOD-like activity in their own right both in vitro and in vivo. Thus, quantification/removal of residual Mn2+ species in Mn-based therapeutics is critical to an unambiguous interpretation of biological data. Herein we report a simple, sensitive, and specific method to determine residual Mn2+ in Mn porphyrin preparations that combines a hydrometallurgical approach for separation/speciation of metal compounds with a spectrophotometric strategy for Mn determination. The method requires only common chemicals and a spectrophotometer and is based on the extraction of residual Mn2+ by bis(2-ethylhexyl)hydrogenphosphate (D2EHPA) into kerosene, re-extraction into acid, and neutralization followed by UV-vis determination of the Mn2+ levels via a Cd2+-catalyzed metallation of the H2TCPP4- porphyrin indicator. The overall procedure is simple, sensitive, specific, and amenable to adaptation. This quantification method has been routinely used by us for a large variety of water-soluble porphyrins.
Full Text
Duke Authors
Cited Authors
- Rebouças, JS; Kos, I; Vujasković, Z; Batinić-Haberle, I
Published Date
- December 5, 2009
Published In
Volume / Issue
- 50 / 5
Start / End Page
- 1088 - 1091
PubMed ID
- 19660888
Pubmed Central ID
- PMC2752483
Electronic International Standard Serial Number (EISSN)
- 1873-264X
Digital Object Identifier (DOI)
- 10.1016/j.jpba.2009.07.002
Language
- eng
Conference Location
- England