Abstract: Linear peptide analogs of somatostatin having the formula: ##STR1## As an example, D-Phe-Phe-Phe-D-Trp-Lys-Thr-Phe-Thr is covered by the above formula (i.e., R.sub.1 is H, R.sub.2 is H, A.sup.1 is D-Phe, A.sup.2 is Phe, A.sup.3 is Phe, A.sup.6 is Thr, A.sup.7 is Phe, A.sup.8 is Thr, and R.sub.3 is NH.sub.2).

Abstract: Peptides which include unnatural amino acids and which either inhibit or promote the secretion of gonadotropins by the pituitary gland and inhibit the release of steroids by the gonads. Administration of an effective amount of such peptides that are GnRH antagonists prevents ovulation of female mammalian eggs and/or the release of steroids by the gonads. The antagonists may be used to treat steroid-dependent tumors, such as prostatic and mammary tumors. The peptides are analogs of the decapeptide GnRH wherein there is at least one residue of an unnatural amino acid in the 3-, 5-, 6- and/or 8-positions. Such unnatural amino acids are useful in the synthesis of peptides and have the formula U.sup.* : ##STR1## where W is (CH.sub.2).sub.n or ##STR2## n is an integer from 1 to 6; and j=1, 2 or 3. Preferably, either Y is N--CN, X is NH and R.sub.2 is alkyl, modified alkyl, alkenyl, alkynyl, aryl or methyl pridyl or ##STR3## where R.sub.11 is H or acyl.

Abstract: Peptides previously disclosed as useful for preventing HIV from binding to cell binding sites have now been shown to have thymoleptic qualities and to be useful for tretment of psoriasis in patients who lack antibodies against HIV.

Abstract: The present invention deals with LHRH antagonists which possess improved water solubility and while having the high antagonist potency of the basic peptides, are free of the edematogenic effects. These compounds are highly potent in inhibiting the release of gonadotropins from the pituitary gland in mammals, including humans.The compounds of this invention are represented by the formulaX--R.sup.1 --R.sup.2 --R.sup.3 --Ser--Tyr--R.sup.6 --Leu--Arg--Pro--R.sup.10 --NH.sub.2whereinX is an acyl group derived from straight or branched chain aliphatic or alicyclic carboxylic acids having from 1 to 7 carbon atoms, or H.sub.2 N--CO,R.sup.1 is D-- or L--Pro, D-- or L--.DELTA..sup.3 --Pro, D--Phe, D--Phe(4--H1), D--Ser, D--Thr, D--Ala, D--Nal(1) or D--Nal (2),R.sup.2 is D--Phe or D--Phe(4--C1)R.sup.3 is D--Trp, D--Phe, D--Pal(3), D--Nal(1) or D--Nal(2),R.sup.6 is D--Cit, D--Hci, D--Cit(Q) or D--Hci(Q) andR.sup.

Abstract: Peptides which include unnatural amino acides and which either inhibit or promote the secretion of gonadotropins by the pituitary gland and inhibit the release of steroids by the gonads. Administration of an effective amount of such peptides that are GnRH antagonists prevents ovulation of female mammalian eggs and/or the release of steroids by the gonads. The antagonists may be used to treat steroid-dependent tumors, such as prostatic and mammary tumors. The peptides are analogs of the decapeptide GnRH wherein there is at least one residue of an unnatural amino acid in the 3-position, the 5-position, the 6-position and/or the 8-position. Such unnatural amino acids are useful in the synthesis of peptides and have the formula U*: ##STR1## where n is an integer from 1 to 6; Y is N--CN, N--CONHR.sub.9, S, O or CH--NO.sub.2 ; R.sub.9 is H, Ac, lower alkyl, aromatic or heterocyclic; X is NH, O, S, M.sub.1 (CH.sub.q).sub.p M.sub.2 or M.sub.1 --(CH.sub.2).sub.p' --M.sub.2 (CH.sub.2).sub.p" --M.sub.3, where M.sub.