wherein a iid group coupled to the y ia group through an 25 x gflg moiety n 66 r 0 1 n k 0 3 r z 0 u 1 9 n and w oh or ona respectively ph 7 2 p gflg 614 compound of general formula i wherein a iie group coupled to the y ia group through an x gflg moiety n 66 r 0 1 n k 0 3 r z 0 u 1 9 n and w oh or ona respectively ph 7 2 p gflg 685 compound of general formula i wherein a iig group coupled to the y ia group through an x gflg moiety n 66 r 0 1 n k 0 3 r z 0 u 1 9 n and w oh or ona respectively ph 7 2 p gflg 602 compound of general formula i wherein a gnrh iii group coupled to the y ia group through an x gflg moiety n 66 r 0 1 n k 0 3 r z 0 u 1 9 n and w oh or ona respectively ph 7 2 p gflg 615 compound of general formula i wherein a iii group coupled to the y ia group through.