Abstract: A novel method of treating prostate adenocarcinoma, prostate benign hypertrophia, endometriosis, dysmenorrhea, hirsuitism, hormono-dependant mammary tumors, treatment and prevention of precocious puberty, induction of a retardation of the appearance of puberty and treatment of acne of mammals comprising administering to warm-blooded animals an effective amount of a peptide of the formulaP Glu-His-Trp-Ser-Tyr-X-Y-Arg-Pro-Z (I)wherein (a) Z is Gly--NH.sub.2, Y is Leu and X is Gly, (b) Z is Gly--NH.sub.2, Y is Leu, X is DN Leu, DN Val, D Abu (.alpha.-aminobutyric acid), D Phe, D Ser, D Thr, D Met, D Pgl, D Lys, Leu, Ile, Nle, Val, N Val, Met, Phe, D Leu, D Arg, D Ser (tbu), D Thr (tbu), D Cys (tbu), D Asp (O tbu), D Glu (Otbu), D Orn (boc), D Lys (boc), D Trp, Trp, 2-methyl Ala, D Tyr, D Met .epsilon.-lauryl D Lys, .epsilon.

Abstract: Disclosed herein are di-O-(aminoglycosyl)-1,3-diaminocyclitol antibacterial agents having on the 1-N-position of the 1,3-diaminocyclitol moiety a dipeptidyl or a tripeptidyl substituent. The compounds are useful antibacterial agents, as are their non-toxic pharmaceutically acceptable acid addition salts. Also disclosed are methods for preparing such agents from di-O-(aminoglycosyl)-1,3-diaminocyclitol antibacterial agents which are unsubstituted at the 1-N-position.