| Abstract: | Fifteen analogs of luliberin (2, LRH) were synthesized by the solid phase method and examined for their ability to block ovulation in the rat. Two analogs, Ac-DAla1,DPhe2,DTrp3,6]-LRH and Ac-DPhe1,DPhe2,DTrp3,6]-LRH, each blocked ovulation at a single injection dose of 250 μg administered at noon on the day of proestrus; three peptides, Ac-DPro1,DPhe2,DTrp3,6]-LRH, Ac-DThi1,DPhe2,DTrp3,6]-LRH and Ac-DTrp1,DPhe2,DTrp3,6]-LRH, were effective at doses of 500 μg each; and four others, Ac-DTrp1,DPhe2,DTrp3,DTrp(Nps)6]-LRH, Chlorambucil-DPhe1, DPhe2, DTrp3,6]-LRH, 1,DThi2,DTrp3,6]-LRH and (2-DLys6]-LRH, gave partial inhibition at doses tested. |
