a structure-affinity relationship has been found requiring the presence of four key elements for good activity : ( 1 ) an additional phenyl ring at the n-benzyl para position of the benzylimidazole nucleus , ( 2 ) an acidic functionality at the ortho position of the terminal aromatic ring , ( 3 ) a lipophilic side chain at the imidazole 2-position of three to five carbon atoms in length , and ( 4 ) a group at the imidazole 5-position capable of hydrogen bonding .
C0013879
elements
C0007009
carbon