1 NSX N~2~,N~6~-bis(biphenyl-4-ylacetyl)-L-lysyl-D-arginyl-N-(2-phenylethyl)-L-tyrosinamide 1.000 2 NSY N~2~,N~6~-bis(biphenyl-4-ylacetyl)-L-lysyl-D-arginyl-N-(2-phenylethyl)-L-phenylalaninamide 0.986