wherein R1, R2, R3, R4, and R5 are each selected from the group consisting of hydrogen, hydroxy, amino, alkyl, alkoxy, cycloalkyl or phenol, optionally substituted with alkyl, alkoxy, hydroxy or halo, and only one of R1, R2, R3, {HEAD ~ R4}, and R5 is {TAIL ~ amino} 
wherein R1 , R2 , R3 , R4 , and R5 are each selected from the group consisting of hydrogen , hydroxy , amino , alkyl , alkoxy , cycloalkyl or phenol , optionally substituted with alkyl , alkoxy , hydroxy or halo , and only one of R1 , R2 , R3 , { HEAD ~ R4 } , and R5 is { TAIL ~ amino }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL