Heterocyclic Amines

Chemical properties

MeIQ, MeIQx, IQ, and PhIP are heterocyclic amines formed by condensation of creatinine with amino acids during the cooking of meat.(Creatinine is a breakdown product of creatine, an important constituent of muscle.) All of these HCAs share a common imidazole ring structure with an exocyclic amino group and, therefore, are known chemically as amino-imidazoazaarenes. Most HCAs, including MeIQ,MeIQx, and IQ, are fully planar aromatic structures with no bulky out-of-plane functionalities; however, PhIP possesses a phenyl moietythat is not necessarily coplanar with the main bicyclic imidazopyridine. All of these HCAs occur as crystalline solids and are soluble in dimethylsulfoxide or methanol. Physical and chemical properties of MeIQ, MeIQx, IQ, and PhIP are listed in the following table.

The Uses of Heterocyclic Amines

MeIQ, MeIQx, IQ, and PhIP have no known commercial uses (IARC 1993).