1 NNH Nor-N-omega-hydroxy-L-arginine 1.000 2 4J5 Amino{[(3s)-3-amino-3-carboxypropyl]amino}methaniminium 0.769 3 AHI 3-{[(E)-amino(hydroxyimino)methyl]amino}propan-1-aminium 0.750 4 BHH N-butyl-N'-hydroxyguanidine 0.750