Radical induced oxidative damage is extremely harmful to tissues and organs
due to molecular modifications brought to polyunsaturated membrane lipids,
proteins and nucleic acids. Oxidative stress is believed to be one of the
pathophysiological mechanisms that. operate in neurodegenerative disorders
such as cerebral ischemias, amyotrophic lateral sclerosis, Parkinson's and
Alzheimer's diseases.
Nitrones oppose oxidative challenges by virtue of their ability to trap ver
y rapidly oxygen or carbon centered radicals thus generating nitroxide radi
cal species which are more stable and biochemically less harmful than the o
riginal radical. However the operational mechanism of nitrones might also g
o beyond direct scavenging of radicals.
The chemical and pharmacological properties of nitrones depend strongly on
the connectivity as well as on the type and position of the substituents in
the compound's architecture.
Heteroaryl-nitrones are known, but except for a few cases (for example pyri
dyl-nitrones) no particular attention has been given to this class of molec
ules. The following review is a survey of the literature reports on this su
bject from 1980 to 1999. The structures were classified according to the he
terocyclic substituent on the nitrone double bond, and documented pharmaceu
tical features were emphasized. Whenever possible heteroaromatic and relate
d aromatic nitrones were compared.