The modulation of the action of isoforms of nitric oxide synthase

The recent patent literature covering the modulation of action of the various isoforms of nitric oxide synthase (NOS) is reviewed. Mammalian biological systems in which nitric oxide (NO) has been shown to be involved are summarised in order to give background to specific patent claims. Claims are generally for therapy of various inflammatory states and for therapy of a number of CNS indications. Emphasis is placed on inhibitors of the several isoforms, since the patent literature is most extensive in this area. Patents are covered by structural class, with amino acids and various classes of heterocycles being the most common types of claimed compounds. Patent applications covering other aspects of control of NO concentrations in mammals are very briefly reviewed, although they fall outside of the scope of NOS per se. These include agents that release NO in situ, and agents that scavenge or sequester NO.