Abstract: The present invention provides cyclic oligopeptides and methods for using the same. The cyclic oligopeptides of the invention are analogues of oxytocin wherein the disulfide linkage between Cys1 and Cys2 are replaced with a more stable amide bond. The cyclic oligopeptides of the invention can also include a glycoside to increase blood-brain barrier penetration. In particular, the cyclic oligopeptide of the invention is of the formula: (A) (SEQ ID NO:2) where one of AA1 or AA6 is an amino acid having a carboxylic acid side-chain and the other is a carboxylic acid having an amine functional group on the side-chain such that X1 and X2 together form an amide bond; and each of AA2-AA5 and AA7-AA11 is independently natural or unnatural amino acids with at least one, typically at least two, often at least three, more often at least four, and most often at least five of which is an amino acid that is present in the corresponding position of oxytocin.

Abstract: Glycopeptide analogs of secretin family peptides, including PACAP and VIP, are described herein. These glycopeptides analogs can have neuroprotective properties and enhanced ability to cross the blood brain barrier (BBB) and/or enhanced stability. These glycosylated peptides can be used as drugs for treatment of CNS disorders, such as Parkinson's disease.

Abstract: Glycosylated peptides with glycosylation at or near the C-terminal domain of the peptide have an enhanced ability to cross the blood brain barrier (BBB) and/or enhanced half-lives. These glycosylated peptides may be used as drugs. For example, a PACAP peptide with a C-terminal glycosylation, e.g., in lieu of the terminal leucine, functions as a PAC1 agonist with enhanced ability to cross the BBB and with enhanced half-life. The peptides can have a pseudoproline residue with glycosylation at or near the C-terminal domain.

Abstract: Glycosylated peptides with glycosyiatiou at or near the C-terminal domain of the peptide have an enhanced ability to cross the blood brain barrier (BBB) and/or enhanced half-lives. These glycosylated peptides may be used as drugs. For example, a PACAP peptide with a C-terminal glycosylation, e.g., in lieu of the terminal leucine, functions as a PAC1 agonist with enhanced ability to cross the BBB and with enhanced half-life. The peptides can have a pseudoproline residue with glycosylation at or near the C-terminal domain.