Heterocycle refers to a cyclic structure consisting of carbon atoms and non-carbon atoms, and non-carbon atoms in the ring are referred to as heteroatoms. Common heteroatoms are nitrogen, oxygen and sulfur.
Heterocyclic compounds a wide range of large quantities, in nature, a wide range of surfaces. Such as certain alkaloids, vitamins, antibiotics and so on.
Heterocyclic drugs have been divided into many different categories due to the heteroatom types and numbers, the number of rings and the number of rings, such as pyridine, quinoline, tropane, phenothiazine Oxazines, benzodiazepines, furans, pyrazolones, pyrimidines and the like.