a chemical compound containing a carbon–nitrogen double bond, with the nitrogen attached to a hydrogen atom (H) or an organic group.

an antibiotic produced by the actinomycete Streptomyces griseus and used to treat tuberculosis

the radical -NH2

a bitter tasting amino acid found in proteins and necessary for nutrition; its absence from the diet leads to a reduced production of spermatozoa

an amino acid that does not occur in proteins but is found in the muscle tissue of vertebrates both in the free form and as phosphocreatine; supplies energy for muscle contraction

an intestinal antibacterial sulfonamide proposed for treatment of dysentery and for sterilization of the colon prior to gastrointestinal tract surgery.