Release of nitric oxide from novel diazeniumdiolates monitored by laser magnetic resonance spectroscopy.
We describe a technique in which for the first time laser magnetic resonance spectroscopy (LMRS) is used online to monitor the release of nitric oxide from synthetic NO donors. LMRS is a spectroscopic method for selective, sensitive (to 1 ppb), and time-resolved NO gas detection in the far-infrared and midinfrared spectral regions. We used two partly novel sets of diazeniumdiolates, the first set derived from N,N-diethylamine (-->DEA-NO), piperidine ((-->PIPE-NO), 2-methylpiperidine (-->MEPIPE-NO), and 2-ethylpiperidine (-->EPIPE-NO) and the second set derived from 2-, 3-, and 4-piperidine carboxylic acids (-->PIPECO-NO, NIPECO-NO, ISONIPECO-NO). We monitored the acid-catalyzed NO liberation from these compounds as influenced by parameters such as pH, temperature, concentration, and molecular structure. PIPECO-NO turned out to be the fastest donor of the group. The 3- and 4-substituted isomer derivatives were only negligibly faster releasers than unsubstituted PIPE-NO, which on the other hand showed to be faster than the higher homologues MEPIPE-NO and EPIPE-NO. The results demonstrate that varying neighboring groups affect the functional diazeniumdiolate group differently. A vicinal carboxyl group increases and alkyl groups decrease the rate of NO release.
Horstmann
Axel
A
Institute of Pharmacy, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany.
Menzel
Lars
L
Gäbler
Ralph
R
Jentsch
Andreas
A
Urban
Wolfgang
W
Lehmann
Jochen
J
D001391:Azo Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D009569:Nitric Oxide / Q000032:analysis*; D020030:Nitric Oxide Donors / Q000138:chemical synthesis / Q000737:chemistry*; D013696:Temperature
D001391:Azo Compounds; D020030:Nitric Oxide Donors; C452539:diazeniumdiolate; D009569:Nitric Oxide