Abstract: Bicyclic somatostatin analogs and pharmaceutically acceptable non-toxic acid addition salts thereof are prepared by the solid phase method. These analogs have the property of inhibiting the release of growth hormone without affecting the level of gastric secretions or without affecting the level of gastric secretions, insulin and glucagon in humans and animals. The compounds are particularly useful in the treatment of acromegaly and diabetic retinopathy. Due to the bicyclic structure, these analogs are resistant to enzymatic metabolism and have a longer duration of activity than somatostatin.

Abstract: Bicyclic somatostatin analogs and pharmaceutically acceptable non-toxic acid addition salts thereof are prepared by the solid phase method. These analogs have the property of inhibiting the release of insulin, glucagon and growth hormone in humans and animals. The compounds are particularly useful in the treatment of diabetes. Due to the bicyclic structure, these analogs are resistant to enzymatic metabolism and have a longer duration of activity.

Abstract: Somatostatin analog, hereinafter designated des(Ala.sup.1 -Gly.sup.2)desaminocys.sup.3 -somatostatin, having the structure: ##STR1## is prepared by controlled stepwise procedures starting with individual amino acid components. This peptide has the property of lowering blood glucose, inhibiting gastric secretion and inhibiting growth hormone release in humans and animals.

Abstract: Somatostatin analogs having the structural formula: ##STR1## wherein R is H, COOH,A is (Asn).sub.n, .alpha.-Abu, Pro, Ala wherein n = 0 or 1,B is Phe, Tyr,C and D are independently Thr, Val,E is Ser, Pro, Ala, Gly,Wherein at least one of A and E is Pro and the ring formed by the peptide backbone contains 35 to 38 atoms and pharmaceutically acceptable non-toxic acid addition salts thereof are prepared by the solid phase method. These peptides have the property of inhibiting the release of insulin, glucagon and growth hormone and decreasing gastric secretion in humans and animals. The compounds are particularly useful in the treatment of diabetes and gastric ulcers.

Abstract: Synthetic novel cyclic hexapeptides having the structure:Cyclo[(N-alkylamino acid)-X-(N-alkylamino acid)'-X-(N-alkylamino acid)"-X]wherein (N-alkylamino acid), (N-alkylamino acid)' and (N-alkylamino acid)" have the structure: ##STR1## wherein R.sup.1 is a lower alkyl group having 1 to 3 carbon atoms and R.sup.2 is hydrogen and methyl or R.sup.1 and R.sup.2 are --CH.sub.2 --N, n being an integer 2 or 3, and form a 4- or 5- membered ring; and X is D- or L-Ala, D- or L-Phe, D- or L-Leu, D- or L-p-halophenylalanyl or D- or L-p-nitrophenylalanyl, with the proviso that when R.sup.1 is methyl and R.sup.2 is hydrogen, X is not D-Ala are prepared. Oral administration of these cyclic peptides improves the digestive efficiency of certain herbivorous animals.

Abstract: This invention is directed to the chemical process for the preparation of the polypeptide, pyroglutamyl-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn and to intermediates in said process. The polypeptide prepared by the present process is useful in the treatment of autoimmune diseases such as Lupus like pathology and specifically for the treatment of Lupus Erythematosus in man. This polypeptide is also useful for selectively stimulating T-cell activity in aging subjects.

Abstract: A novel tetrapeptide L-2-ketopiperidine-6-carbonyl-L-histidyl-L-thiazolidine-4-carbonyl-.beta.- alanin-amide, (L-Kpc-L-His-L-Tca-.beta.-ala-NH.sub.2), is a stimulant of the central nervous system. It is preparable by standard peptide synthetic procedures.

Abstract: Novel protecting groups for peptides containing a cysteine residue. Process for the synthesis of peptides containing a cysteine residue wherein the mercapto function of the cysteine residue is protected by an acetamidomethyl radical or other labile blocking group. Novel intermediates useful in peptide synthesis.

Abstract: The disclosed invention relates to .epsilon.-N-pyridyl-4-methyloxycarbonyllysine valuable in the synthesis of lysine containing peptides to the process of preparing this compound starting with 4-pyridyl-carbinol and succinimido-chloroformate and to the pyridyl-4-methyl-succinimidocarbonate intermediate in this process.

Abstract: The disclosed invention relates to .epsilon.-N-pyridyl-4-methyloxycarbonyllysine valuable in the synthesis of lysine containing peptides to the process of preparing this compound starting with 4-pyridylcarbinol and succinimido-chloroformate and to the pyridyl-4-methyl-succinimidocarbonate intermediate in this process.

Abstract: Novel tripeptides are disclosed. These tripeptides have anti-depressant activity and thyrotropin releasing hormone activity. Processes for preparing these tripeptides are also disclosed.

Abstract: A process for preparing peptides containing lysine wherein the terminal amino group of lysine is protected by a pyridyl-4-methyloxycarbonyl group during formation of the peptide and removing this group with zinc in acid.

Abstract: Novel N-protected-.alpha.-amino acid compounds are disclosed in which the amino functionality is protected by a 1-methylcyclobutyloxycarbonyl or 1-methylcyclohexyloxycarbonyl. Processes for the synthesis of amino acids containing these protecting groups and the use of these novel amino acid compounds in the preparation of peptides are also disclosed.