CA2165200A1

CA2165200A1 - Neuropeptide y antagonists and agonists

Info

Publication number: CA2165200A1
Application number: CA002165200A
Authority: CA
Inventors: Ambikaipakan Balasubramaniam
Original assignee: University of Cincinnati
Current assignee: University of Cincinnati
Priority date: 1993-06-18
Filing date: 1994-06-16
Publication date: 1995-01-05
Also published as: AU7174494A; JPH11501281A; WO1995000161A1; EP0707490A1; ZA944338B

Abstract

The invention discloses analogs which behave as NPY antagonists and agonists; and methods of their use for controlling a biological activity such as appedte and cardiovascular function.

Description

WO95/00161 PCT~S94/06837 ~ Q

NEUROPEPTIDE Y ANTAGONISTS AND AGONISTS
Backqround of the Invention This invention relates to peptide derivatives 5 which are antagonists or agonists of neuropeptide Y.
Neuropeptide Y (NPY), is a 36-residue peptide characterized by a tyrosine (Y) residue at its N-terminus and a tyrosine amide residue at its C-t:erminus. The peptide was isolated from porcine brain (Tatemoto Proc.
10 Natl. Acad. sci. U.S.A. 79:5485-5489 "L982) and is considered to be a neurotransmitter or neuromodulator widely distributed in the central and peripheral nervous systems (Allen et al., Neurochem. Int. 8:1-8, 1986). It is the most abundant peptide present iIl the mammalian 15 brain and heart (Edvinsson et al., Trends Pharmol. Sci.
8:231-235, 1987; Gu et al., Histochem. Cytochem. 32:467-472, L984), and is among the most potent vasoconstrictor peptides isolated to date (Lundberg et al., Acta Physiol.
Scand. 121:325-332, 1984). However, NPY elicits several 20 physiological responses by activating specific pre- and post-synaptic receptors. Centrally, N]?Y is thought to be involved in the regulation of food intake, memory processing and circadian rhythm (Shei~l et al., FEBS
Lett. 245: 209-214, 1989). In the periphery, NPY seems 25 to function as a transmitter in sympathetic nerves where it interacts with norepinephrine mainly in the regulation of vasculartone (Sheikh et al. FEBS Lett. 245:209-214, 1989).
Different structure-activity relationships for NPY
30 analogs in various model systems have indicated that multiple NPY receptor subtypes exist (~ichel, Tips 12:389-394, 1991). Wahlestedt and coworkers (Regul.
Pept. 13:307-318, 1986) first suggested the existence of two distinct subtypes of NPY receptors. Post-synaptic (Yl-type) effects could be obtained with the complete NPY

WO95/00161 PCT~S94/06837

2~6~

molecule, while pre-synaptic (Y2-type) effects were found elicited by long C-terminal fragments, as well as with the entire NPY molecule. Thus, both Yl and Y2 receptors exhibit nearly equal affinity to NPY and its homologous 5 peptide, peptide YY, but only the Y2 receptors could bind to shorter carboxyl-terminal fragments including NPY(13-36) as described by Sheikh et al. (FEBS Lett. 245:209-214, 1989). However, since NPY receptors in rat cardiac ventricular membranes discriminate between NPY and 10 peptide YY but bind NPY(13-36), it was suggested that this system be classified as a subtype of Y2 or a new class (designated Y3) of receptors as discussed below (Balasubramaniam et al. Peptides 11:545-550, 1990).
NPY is also present in high concentrations in a 15 distinct population of nerve fibers innervating the heart and blood vessels (Wharton et al., Ann . N. Y. Acad . sci .
611:133-144, 1990). NPY is now regarded as the predominant peptide present in the cardiovascular system of mammals. This observation has led to numerous studies 20 of the cardiovascular properties of NPY. For example, several investigations have reported that NPY is a potent vasopressor peptide and that it inhibits the coronary blood flow and contractility in isolated perfused hearts (e.g., see Balasubramaniam et al., Regul. Pept. 21:289-25 299, 1988; Allen et al. Regul . Pept . 6:247-253, 1983;
Rioux et al. Peptides 7:27-31, 1986). Furthermore, NPY
is also capable of (1) inhibiting the contractile force of isolated cardiac muscles (Balasubramaniam et al.
supra) and myocytes (Piper et al. Nuanyn-Scniedberg's 30 Arch . Pharmol . 340: 333-337, 1989) and (2) the adenylate cyclase activity and cAMP production by cardiac muscles (Kassis et al., J. Biol. Chem. 262: 3429-3431, 1987) and myocytes (Kassis et al. supra; Millar et al. Nuanyn-Sc~iedberg~s Arch. Pharmol. 338: 426-429, 1989), 35 respectively. Specific receptors of NPY in rat cardiac ~095/00161 ~ 0 ~ PCT~S94/06837 ventricular membranes have been characterized and reported to be more selective to NPY than previously charac1:erized NPY receptors as discussed above (Balasubramaniam et al. Peptides 11:545-550, 1990). The 5 presente of specific receptors of NPY in rat cardiac membranes, the Y-3 receptor, was also reported by visualization with Na biotinyl-NPY analogs (Balasubramaniam et al. Peptides 11: 1151-1155, 1990).
The following table (the abbreviations used are 10 commonly known in the art and are descri.bed infra) shows the amino acid homology between NPY and PYY:
s 10 15 zo 2s 30 3s ~ ~ ~ + ., ~ ~
Numan NPY ~r~Y ~ APAEDMARYYSALRHYINLITRQRY
15 Rst NPY ~r~Kl~L~ F`A ~rYYSALRHYlNLlTRQRY
Rabbit NPr ~ra~.r_: ~rA :~YYSALRHYINLITRQRY
Guinea pig NPY YPSKPDNPGEDAPAEDMARYYSALRHYINLI~RQRY
Porcine NPY YPSKPDNPGEDAPAEDLARYYSALRHYINLITRQRY

Human PYY YPIKPEAPGEDASPEELNRYYASLRHYLNLVTRQRY
2 0 Porcine P~Y --A--------------s------------------Rat PYY --A--------------S------------------NPY has been implicated in the pathophysiology of a number of diseases including, without limitation, obesity, hypertension and chronic heart failure (CHF) 25 because: (1) hypothalamic NPY levels are elevated in obese rats and decreased in cancer anorectic rats; (2) plasma NPY levels are elevated in CHF and hypertensive patienl:s; (3) negative cardiac inotropic: and chronotropic actions; and (4) inhibition of libido and circadian 30 rhythm. Thus, since NPY has been shown to be important for regulating a plurality of physiologi.cal events we have set out to design a series of receptor-specific analogs that selectively modulate a vari.ety of biological activities, e.g., appetite and blood pressure activities.

WO95/00161 PCT~S94/06~7 2~ QQ 4 -SummarY of the Invention In general, the invention features analogs which behave as NPY antagonists and agonists.
In one aspect, the present invention features 5 compounds having the formula:
Rl ' R2 ~ Al-A2-A3-A4-A5-A6-y_A2 5 _A2 6 _A2 7 _A2 8 -A29_A30_A31_A32_A33_ A34-A35-A36 - W (I) wherein each each R1 and R2, independently, is H, C1-C12 alkyl (e-g-~methyl)~ C6-C18 aryl (e.g., phenyl)~ Cl-C12 acyl (e.g., formyl, acetyl, and myristoyl), C7-C18 aralkyl (e.g., benzyl), or C7-C18 alkaryl (e.g., p-methylphenyl);
A1 is Tyr, or any aromatic amino acid;
A2 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal or Asp;
A3 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ile, Val, Aib, Anb, Nle, or N-Me-Leu;
A4 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a br~nçhe~ or straight chain Cl-Cl0 alkyl group, or a C6-Cl8 aryl group), or Orn;
A5 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, or D-Trp;
A6 is Gly or is the D- or L- isomer selected from the group consisting of Asp, Glu, N-Me-Asp, Ala, or Aoc;
30 Y is A -A8-A9-Alo-All-Al2-Al3-Al4-Al5-Al6-Al7-Al8 Al9-A2o-A2l-A22-A23-A24 or is absent, where A7 is Asn, Ala, Gln, Gly, or N-Me-Asn;
A8 is Pro, Ser, Thr, Hyp, D-Ala, N-Me-Ala, Ac6c, or D-Pal;
A9 is Gly, N-Me-Gly, Ala, or Trp;
A10 is Glu, Asp, N-Me-Glu, Ala, or Nva;
Al1 is Asp, Glu, N-Me-Asp, Ala, or Anb;

WO95/00161 21~ ~ 2 ~0 PCT~S94/06837 A12 is Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A13 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, Ser, Thr, N-Me-Ser, N--Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A14 is Ala, Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A15 is Glu, Asp, N-Me-Glu, Ala, or Nva;
A16 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A17 is Met, Leu, Ile, Val, Aib, Anb, Nle, or N-Me-Leu;
A18 is Ala, Asn, Gln, Gly, N-Me--Asn, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
Al9 is the D- or L- isomer selec:ted from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-C1O alkyl group, or a C6-C18 aryl group), or Orn;
A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me--Thr, Ala, Nal, Thi, Phe, Bth, Pcp, o:r N-Me-Ala, A23 is Ala, Ser, Thr, Nal, Thi, Phe, Bth, Pcp, N-Me-Ala, N-Me-Ser, or ~-Me-Thr;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
25 A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, ,a branched or straight chain C1-C1O alkyl group, or a C6-Cl8 aryl group), or Orn;
30 A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, ~-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a branched or straight chain Cl-ClO alkyl group, or a C6-C18 aryl group)~ or Orn;

WO95/00161 PCT~S94/06~7 ~6~2~ - 6 -A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring (e.g., Me-Trp);
5 A23 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
lO A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;
A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring (e.g., Me-Trp), Ant, Ser, N-Me-Ser, Thr, N-~e-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative (e.g., 2-chlorotroptophan, or Tcc);
A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a brAnch~ or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A36 is Tyr, or any aromatic amino acid;
W is -OH, -N-R3R4, or OR5 (where R3, R4, and R5 , independently, is H, Cl-C12 alkyl (e.g., methyl), C6-C18 aryl (e-g-~ phenyl)~ Cl-Cl2 acyl (e.g., formyl, acetyl, and myristoyl), C7-C18 aralkyl (e.g., benzyl), or C7-C18 alkaryl, (e.g., p-methylphenyl); wherein, 35 in formula (I) each bond can represent either a peptide wo 95~00161 ~ 1 6 5 ~ ~ Q PCT~S94/06837 .

bond or a pseudopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.
Preferably, said pseudopeptide bond is between 5 amino acid residues A29-A30, A34-A35, and A35-A36.
Preferred compounds formula (I) include those in which A32 is D-Trp, D-Phe, D-Tyr, D-Bip, D-Dip, D-Bth, D-Nal, 2-Cl-Trp, Tcc, Trp, or a pharmaceutically acceptable salt thereof. In yet other preferred embodiments of the 10 invention the compounds of formula (I) include those in which Y (A7-A24) is deleted. Preferably, the compound of formula (I) is ~D-Trp32]NPY, cyclo (2/27) Des-AA7 24[ASp2 D_Ala6 D_Ly527~ D-Trp32]NPY, Des-AA7 24tD-Ala , AoC6 D-Trp32]NPY Des-AA7~24[D-Ala5 Gly6 D_Trp32]Npy or 15 Des-AA~7~24[D-Trp5~ AoC6, D-Trp32]NPY -In another aspect, the invention features acompound having the formula:
Rl 20 R2 ~ X-A27-A28-A29-A3o-A3l-A32-A33-A34-A35-A36- W (II) wherein X is a chain of 0-7 amino acids, inclusive the N terminal one of which is bonded to each Rl and R2;
wherein each R1 and R2, independently, is H, Cl-C12 alkyl (e.g., methyl), C6-C18 aryl (e.g., phenyl), Cl-C12 acyl (e.g., formyl, acetyl, and myristoyl), C7-Cl8 aralkyl (e.g., benzyl), or C7-C18 alkaryl (e.g., p-methylphenyl);
A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring (e.g., Me-Trp);
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn, or is deleted;

WO95/00161 PCT~S94/06837 2~2~ --A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu, or is deleted;
A31 is Ile, Cys, D-Ala, Leu, Val, Aib, Anb, N-Me-Ile, or is deleted;
5 A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring (e.g., Me-Trp), Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative (e.g., 2-chlorotroptophan, or Tcc);
A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-Cl8 aryl group), or Orn;
A36 is Tyr, or any aromatic amino acid;
W is -OH, -N-R3R4, or OR5 (where each R3, R4, and R5 , independently, is H, Cl-C12 alkyl (e.g., methyl), C6-C18 aryl (e.g., phenyl), Cl-C12 acyl (e.g., formyl, acetyl, and myristoyl), C7-C18 aralkyl (e.g., benzyl), or C7-C18 alkaryl (e.g., p-methylphenyl); wherein, in formula (II) each bond can represent either a peptide bond or a pseudopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.
Preferred compounds of formula (II) include those 35 where X is A2o-A2l-A22-A23-A24-A25-A26 where ~O 95/00161 ~ 1 S ~ 2 0 ~ PCT/US94/06837 _ g _ A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, or N-~Ie-Thr;
A23 is Ala, Ser, Thr, Nal, Thi, E'he, Bth, Pcp, N-Me-Ala, N-Me-Ser, or N-Me-Thr;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer select:ed from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~-NH-R (where R is H, a branched or straight chain C1-ClO
alkyl group, or a C6-CI8 aryl group), or Orn;
A26 is the D- or L- isomer selecl ed from the group consisting of His, Thr, 3-Me-His, ,~-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys--NH-R (where R is H, a branched or straight chain Cl-ClO alkyl group, or a C6-Cl8 aryl group), or Orn;
W is -~H, -N-R3R4, or OR5 (where each R3, R4, and R5, 20 independently, is H, Cl-Cl2 alkyl (e.g., methyl), C6-C18 aryl (e.g., phenyl), Cl-C12 acyl (e.g., formyl, acetyl, and myristoyl), C7--C18 alkaryl; or a pharmaceutically acceptable 25 salt tlhereof.
Preferably, said pseudopeptide k,ond is between amino acid residues A29-A30, A34-A35, an~ A35_A36.
Preferably, the compound of for~ula (II) is tD-Trp28, D-Trp32]NPY (27-36), (Des-Asn29[D-Trp28, D-30 Trp32]NPY(27-36), Des-Asn29[D-Trp28, D-Trp32, Nva34]NPY(27-36), Des-Asn29tTrp28, Trp32, Nva34]NPY(27-36), and tD-Trp28, Ant32, Nva34]NPY(27-36), Des-Asn29[D-Trp28, Ant32, Nva34]NPY(27-36), or Des-Asn29, Arg33[D-Trp28, Ant32, Nva34]NPY(27--36).

WO95/00161 ~Q ~ PCT~S94/06837~

In another aspect the invention features a compound having a formula:
Rl Al-A2-A3-A4-As-A6-A7-A8-A9-y-Al8-Al9-A2o-A2l-A22-A23-A24 A25_A26_A27_A28_A29--A3-A31-A32-A33--A34--A35--A--W
tIII) wherein a disulfide bond is between A7 and A21 or is absent; wherein each each Rl and R2, independently, is H, Cl-Cl2 alkyl (e.g., methyl)~ C6-C18 aryl (e.g., phenyl), C1-C12 acyl (e.g., formyl, acetyl, and myristoyl), C7-Cl8 aralkyl (e.g., benzyl), or C7-Cl8 alkaryl (e.g., p-methylphenyl);
Al is Tyr, or any aromatic amino acid;
20 A2 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal or Asp;
A3 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ile, Val, Aib, Anb, Nle, or N-Me-Leu, A4 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A5 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, or D-Trp;
A6 is Gly or is the D- or L- isomer selected from the group consisting of Asp, Glu, N-Me-Asp, Ala, or Aoc;
A7 is Cys, Glu, Asn, Ala, Gln, Gly, or N-Me-Asn;
A8 is Pro, Ser, Thr, Hyp, D-Ala, N-Me-Ala, Ac6c, or D-Pal;
35 A9 is Gly, N-Me-Gly, Ala, or Trp;
Y is AlO_All_A12_A13_A14_A15_A16_A17 or is absent, where Al is Glu, Asp, N-Me-Glu, Ala, or Nva;

95/00161 ~1 6 ~ 2 ~ ~ PCT~S94106837 ~0 A11 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A12 is Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A13 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, o:r N-Me-Ala Thr;
A14 is Ala, Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A15 is Glu, Asp, N-Me-Glu, Ala, or Nva;
A16 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A17 is Met, Leu, Ile, Val, Aib, Anb, Nle, or N-Me-Leu;
A18 is, Ala, Asn, Gln, Gly, N-Me-Asn, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
Al9 is the D- of L- isomer selected from the group consisting of Arg, D-homo-Arg, D-diethyl-homo-Arg, D-Lys-~-NH-R (where R is H, a b:ranched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A20 is Tyr, or any aromatic amino acid;
20 A21 i~ Cys, Lys, Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala, A23 i~ Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
25 A24 i6 Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 i~ the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, ~-pyrazolylAlAn;~e~ N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (w:here R is H, a WO95/00161 PCT~S94/06837 2~ 2~a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring (e.g., Me-Trp);
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
10 A29 is Asn, Ala, Gln, Gly, N-Me-Asn or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;
A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring (e.g., Me-Trp), Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative (e.g., 2-chlo OLL u~ophan, or Tcc);
A33 is the D- or L- isomer is selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), Orn, is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;5 A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;0 A36 is Tyr, or any aromatic amino acid;
W is -OH, -N-R3R4, or OR5 (where R3, R4, and R5, independently, is H, Cl-C12 alkyl (e.g., methyl), C6-C18 aryl (e.g., phenyl,), C1-Cl2 acyl (e.g., formyl, acetyl, and myristoyl), ~095/00161 X~ S~ 0~ PCT~S94/06837 C7-Cl8 aralkyl (e.g., benzyl), or C7-Cl8 alkaryl;
wherein, in formula (III) each bond can represent either a peptide bond or a pseudLopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.
Preferably, said pseudopeptide bond is between amino acid residues A29-A30, A34-A35, and A35-A36.
Preferably the compound of formula (III) is 10 cyclo(7/21), Des AA10-l7[Cys7 Cys21 D-Trp32]NPY
cyclo(7/21)~ Des AA10-l7~Glu7 Lys21 D_~rp32]Npy In another aspect, the invention, features a compound with pseudopeptide bonds having the formula:
R
R2 ~ A -Al9-A20-A2l-A22-A23-A24-A25-A26-~27-A28 A29 A30 A3 A32_A33_A34_A35_A36 - W (IV) wherein each0 each R1 and R2, independently, is H, cl-c12 alkyl (e.g., methyl), C6-C18 aryl (e.g., phenyl), C1-C12 acyl (e.g., formyl, acetyl, and myristoyl), C7-Cl8 aralkyl (e.g., benzyl), or C7-Cl8 alkaryl (e.g., p-methylphenyl);5 A18 is Ala, Asn, Gln, Gly, N-Me-Asn, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A19 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala, WO95/00161 PCT~S94/06~7 2~ ~52~

A23 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-Cl8 aryl group), or Orn;
A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, ~-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
15 A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring (e.g., Me-Trp);
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn, or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;
25 A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring (e.g., Me-Trp), Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative (e.g., 2-chlorotroptophan, or Tcc);
A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain C1-C1O alkyl group, or a C6-C18 aryl group), Orn, or is deleted;

2 ~ ~
WO95/00161 - 15 - PCT~S94/06837 A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain Cl-ClO alkyl group, or a C6-Cl8 aryl group), or Orn;
A36 is Tyr, or any aromatic acid;
W is -OH, -N-R3R4, or OR5 (where each R3, R4, and Rs , independently, is H, Cl-Cl2 alkyl (e.g., methyl), C6-Cl8 aryl (e.g., phenyl), Cl-Cl2 acyl (e.g., formyl, acetyl, and myristoyl), C7-Cl8 aralkyl (e.g., benzyl), or C7-Cl8 alkaryl (e.g., p-methylphenyL);
wherein, in formula (IV) each bond can represent either a 15 peptide or a pseudopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof. In preferred embodiments, the compound con1:ains a pseudopeptide bond between A30 and A3l; A3l and A32; or A320 and A33.
In another aspect, the invention features a method of suppressing an NPY mediated physioloqical response in a tissue other than the heart in a subject comprising administering to said subject a compound having the5 following formula:
Rl \
R2 -- Al8--A19--A2o--A2l--A22-A23--A24--A25--A26--~ 27--A28 A29 A30 A3 A32-A33-A34-A3 5 -A3 6 _ W

wherein each each R1 and R2, independently, is H, Cl-Cl2 alkyl (e.g., methyl), C6-Cl8 aryl (e.g., phenyl), Cl-Cl2 acyl (e.g., formyl, acetyl, and myristoyl), C7-Cl8 aralkyl (e.g., benzyl), or C7-Cl8 alkaryl WO95/00161 PCT~S94/06837 2~ a (e.g., p-methylphenyl);
A18 is Ala, Asn. Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
Al9 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, or any aromatic amino acid;
10 A22 is Ser, Thr, N-Me-Ser, or N-Me-Thr;
A23 is Ala, Ser, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, D-homo-Arg, D-diethyl-homo-Arg, D-Lys-~-NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, ~-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys~ -NH-R (where R is H, a branched or straight chain Cl-C10 alkyl group, or a C6-C18 aryl group)~ or Orn;
A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring (e.g., Me-Trp);
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn, or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;
A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-WO95/00161 ~ J ~ ~ 2 ~ ~ PCT~S94/06837 .

Tyr, a tethered amino acid with an indole ring (e.g., Me-Trp), Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative (e.g., 2-chlorotroptophan, or Tcc);
5 A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
10 A34 is Gln, Asn, N-Me-Gln, Nle, Nva, A~a, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-~-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A36 is Tyr, or any aromatic acid;
W is -OH, -N-R3R4, or OR5 (where each ~3, R4, and R5 , independently, is H, C1-C12 alkyl (e.g., methyl), C6-C18 aryl (e.g., phenyl), Cl-C12 acyl (e.g., fonmyl, acetyl, and myristoyl), C7-C18 aralkyl (e.g., benzyl), or C7-Cl8 alkaryl (e.g., p-methylphenyl); wherein, each bond can represent either a peptide bond or a pseudopeptide bond, provided th~at said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.
Preferably, said pseudopeptide bond is between amino acid residues A29-A30, A34-A35, arld A35_A36. or a pharmaceutically acceptable salt thereof.
In preferred embodiments, the method suppresses the activity of the NPY (Y-1) receptor or the NPY (Y-2) receptor.
In another aspect, the invention features a method of su~ppressing a NPY(Y-l) receptor mediated physiological 35 response in the hypothalamus of a subject comprising WO95/00161 PCT~S94/06837 2~

administering to said subject the compound of formula (I).
In another aspect, the invention features a method of suppressing the blood pressure of a subject 5 experiencing hypertension which comprises administering to said subject the compound of formula (I).
In another aspect, the invention features a method of suppressing a NPY(Y-3) receptor mediated physiological response in the cardiovascular system of a subject 10 comprising ~min;~tering to said subject the compound of formula (IV).
In other preferred embodiments, a therapeutically effective amount of a compound of formula (I), (II), (III) or (IV) and a pharmaceutically 15 acceptable carrier substance, e.g., magnesium carbonate or lactose, together form a therapeutic composition capable of suppressing an NPY mediated physiological response. This composition can be in the form a pill, tablet, capsule, liquid, or sustained released tablet for 20 oral administration; or a liquid for nasal a~; n; stration as drops or spray; or a liquid for intravenous, subcutaneous, parenteral, or intraperitoneal administration.
Another preferred form for a~ ;ctration 25 biodegradable sustained-release composition for intramuscular a~;n;~tration to a subject in need of the composition. Preferably, the composition includes a lipophilic salt and is suitable for administration in the form of an oil emulsion or dispersion to a subject in 30 need of the composition.
In yet another aspect, the invention features methods for suppressing an NPY mediated physiological response in a subject; such methods involve administering one or more of the above mentioned compounds to a subject 35 in a dosage effective to lower blood pressure; to WO95/00161 ~ 2 ~ Q PCT~S94/06837 suppress the appetite; to augment the libido; to stimulate cardiovascular function; on to modulate the circaclian rhythm.
In still another aspect, the invention features 5 methods for stimulating an NPY mediated physiological response in a subject; such methods involve a~m;n;~tering one or more of the above mentioned comp~ounds to a subject in a dosage effective to increase blood pressure; to increase the appetite; to augment the libido; or to 10 stimulate cardiovascular function.
The symbol Al, A2, A3, and the like; and Tyr, Lys or the like, as found in a peptide sequence herein stands for an amino acid residue, e.g., =N-CH(R)-CO- when it is at the N-terminus, or -NH-CH(R)-CO- when it is at any 15 other position, where R denotes the sid;e chain (or identifying group) of an amino acid or its residue. For example, R is -CH2COOH for Asp, R is -H for Gly, R is -CH2OH for Ser, R is -CH3 for Ala and R is -CH2CH2CH2CH2NH2 for Arg. Also, when the amino acid re~idue is optically 20 active, it is the L-form configuration that is inten~
unless the D-form is expressly designated. By pseudopeptide bond is meant that the carbon atom partic:ipating in the bond between two residues is reduced from a carbonyl carbon to a methylene carbon, i.e., CH2-25 NH; or less preferably that of C)-NH is replaced with any of CH2 S, CH2-~ CH2-CH2~ CH2-CO, or CH~-CH2. (A
pseudopeptide peptide bond is symbolized herein by or "~".) A detailed ~ sion of the chemistry of pseudopeptide bonds is given in Coy et al. (1988) 30 ~etrahedron 44:835-841.
~ In other embodiments, the compounds of Formulae (I), I~II), (III), or (IV) are cyclic. Preferably, the cyclixation is formed by a disulfide or lactam bridge (amide bond). In this disclosure, the disulfide or amide 35 bond ~hich links two residues in a compound of the WO95/00161 PCT~S94/06837 ~ - 20 -invention are formed between the side chain functionalities. That is, between the side-chain carboxyl group of an acidic amino acid residue (e.g., Asp or Glu) and the side chain amino group of a basic amino 5 acid residue (e.g., Lys or Orn), or between the side chain sulfhydryl groups of two Cys. In all formulae set forth herein, the amide or disulfide bond between two residues are not shown. A compound of this invention is also denoted by another format, e.g. cyclo (2/27) Des-AA7 24tASp2 D_Ala6 D_Ly527~ D-Trp32] NPY and cyclo(7/21) Des AA10-17 t CyS7, Cys21, D-Trp32]NPY-Preferred cyclic compounds of the invention are 1 (2/27) Des AA7-24[Asp2, D-Ala6, D-Lys27, D-Trp ] NPY
and cyclo(7/21) Des AA10-17[Cys7, Cys21, D-Trp32]NPY
In another aspect, the invention features novel dimeric analogs of NPY. The dimer may be formed by either including one compound of Formula I, II, II, or IV
and one compound of Formula I, II, III, or IV. In one embodiment, the dimer is formed by utilizing a 20 dicarboxylic acid linker capable of binding to a free amine, either primary or secondary, located within each compound. See R. Vavrek and J. Stewart, Peptides:
Structure and Function 381-384 (Pierce Chemical Co.
1983). Examples o~ suitable dicarboxylic acid linkers 25 are succinic acid, glutamic acid, and phthalic acid. In other embodiments, the dimer is formed by utilizing an amino acid linker capable of binding to a free amine group of one compound and a free carboxylic acid group of the other compound. Preferably, the amino acid linker is 30 a non-~-amino acid. Examples of suitable amino acid linkers are amino-caproic acid and amino-valeric acid.
In yet another embodiment, the dimer is formed by disulfide bridge between cysteines located within each compound. See M. Berngtowicz and G. Piatsueda, Peptides:
35 Structure and Function 233-244 (Pierce Chemical Co.

~o 95~00161 ~ ~ 6 5 ~ ~ ~ PCT~S94/06837 1985); F. Albericio, et al., Peptides :L990 535 (ESCOM
1991) -Preferred dimeric compounds of the invention are Bis(31/31) ~Cys31, Trp32, Nva34]NPY(27-36), and Bis(31/31) (Cys3~ Trp32, Nva34]Npy(3l-36)~
As set forth above and for convenience in describing this invention, the conventional and nonconventional abbreviations for the various amino acids are used. They are familiar to those skilled in the art;
10 but for clarity are listed below. All peptide se~le~c~
mentioned herein are written according to the usual convention whereby the N-terminal amino acid is on the left and the C-terminal amino acid is on the right. A
short line between two amino acid residues indicates a 15 peptide bond.

Abbreviations (common):

Asp = D = Aspartic Acid Ala = A = Alanine 20 Arg = R = Arginine Asn = N = Asparagine Cys = C = Cysteine Gly = G = Glycine Glu = E = Glutamic Acid 25 Gln = Q = Glutamine His = H = Histidine Ile = I = Isoleucine Leu = L = Leucine Lys - K = Lysine 30 Met = M = Methionine Phe = F = Phenylalanine Pro = P = Proline Ser = S = Serine Thr = T = Threonine WO95/00161 PCT~S94/06837 æo~ ~

Trp = W = Tryptophan Tyr = Y = Tyrosine Val = V = Valine Abbreviations (uncommon):
5 Aoc = (8-aminooctanoic acid:
Orn = Ornithine Nal = 2-napthyl~l~n;ne Thi = 2-thienylalanine Pcp = 4-chlorophenylalanine 10 Bth = 3-benzothienyalanine Bip = 4,4'-biphenyl~l~n; ne Tic = tetrahydroisoquinoline-3-carboxylic acid Aib = aminoisobutyric acid Anb = ~-aminonormalbutyric acid 15 Dip = 2,2-diphenylalanine Ac6c = l-aminocyclohexanecarboxylic acid D-Pal = ~-(3-pyridyl)alanine;
Tcc = tetrahydrocarbolenecarboxylic acid Nva = norvaline 20 Ant = anthranilic acid Hyp = hydroxyproline Nle = norleucine The compounds of the invention are useful for 25 reducing, suppressing or mitigating the effects of NPY.
For example, the col..~o~nds of the invention are especially useful in treating any number of ~ Pcses that involve eating disorders, cardiovascular function, alterations in sexual function, as well as disorders of 30 sleep and circadian rhythms (see, e.g., Harrison's Principles of Internal Medicine, McGraw-Hill Inc., New York, 12th ed.). Specific examples of such disorders, include without limitation, obesity, anorexia, hypertension, hypotension, congestive heart failure, wo Ys/n~l6~ 5 2 ~ ~ PCT~S94/06837 impotence, dyssomnias and rapid time-zone change syndrome. Strategic design of the NPY antagonists, as described herein, allows for the selective antagonism of different classes of NPY receptors, e.g., Y3 cardiac 5 receptors, without adverse interaction with other NPY
receptors. The compounds are also useful for stimulating NPY receptor mediated events, e.g., increasing the blood pressure of a subject.
Other features and advantages of the invention 10 will be apparent from the following description of the preferred embodiments thereof, and from the claims.
DescriPtion of Preferred Em]bodiments The drawings will first be desc:ribed.
DRAWINGS
Fig. 1 shows the comparison of the effects of D-Trp or D-Trp(CHO) substituted NPY analogs (1.0 ~M) on the isoproternol stimulated adenylate cyclase activity of rat hypothalmic membranes. Iso, isoproternol. I., tD-Trp32]
Trp32lNPY; II, ~D-Trp(CHO)32]NPY; III, tD-Trp34]NPY; IV, ~D-Trp(CHO)34]NPY; V, [D-Trp36]NPY; VI, [D-Trp(CHO)36]NPY;
a=p,0.01 compared to isoproternol; b, not signifcant compared to isoproternol.
Fig. 2 shows the displacement of l25I-NPY bound to rat hypothalamic membranes by increasing concentrations 25 NPY (-) and [D-Trp32] NPY (O).
Fig. 3 shows the dose-response effects of increasing concentrations of [D-Trp32] NPY (O), NPY alone (-); NPY in the presence of 30 (~) and 300 (O) nM doses of [D-Trp32] NPY on the isoproterenol stimulated adenylate 30 cycla~se activity of rat hypothalamic membranes.
Fig. 4 shows the comparison of the effects of [D-Trp32~NPY (1.0 ~M) on the inhibition of' isoproterenol stimulated adenylate cyclase activity of rat hypothalamic membranes by NPY (100 nM) and serotonin tl00 nM). a = p <

WO95/00161 PCT~S94/06837 2~5?~0~ ~

0.01 compared to isoproterenol; b, not significant compared to isoproterenol .
Fig. 5 æhows the antagonism o~ NPY induced f~e~g in rats by ~D-Trp32]NPY.
Fig. 6 shows the effects of 1 ~M doses of NPY and its analogs tL-Trp32] NPY, tD-Trp32(CH0)] NPY, [D-Nal3 NPY, ~D-Hyp32] NPY, [(3-1-Tyr27), D-Trp32] NPY and t(3-l-Tyr27~36), D-Trp32] NPY on isoproterenol stimulated adenylate cyclase activity of rat hypothalamic membranes.
(iso = isoproterenol); (a 5 p < 0.005 vs. iso.); (n.s. =
not significant).
Fig. 7 shows the effects of increasing concentrations of NPY in the absence (0) and presence (-) of Des-AA7 24~D-Ala5, Aoc6, D-Trp32] NPY (1 ~M) th 15 isoproterenol stimulated cAMP production by SK-N-MC
cells. Also shown is the effect of increasing concentrations of Des-AA7~24tD-Ala5, Aoc6, D-Trp32]NPY (0) on the isoproterenol s~im~ ted cAMP production by SK-N-MC cells.
Fig. 8 shows the effects of increasing concentrations of NPY on the blood pressure of anesthetized rats in the absence (0) and presence (-) of 200 nmol/kg of Des-AA7~24~D-Ala5, Aoc6, D-Trp32]NPY.
Fig. 9 shows the effects of increasing 25 conc~trations of NPY (0) and NPY (18-36) (~) on the binding of 125I-NPY to SK-N-BE2 cells.
Fig. 10 shows the effects of NPY (0), NPY (18-36) (~) and NPY in the presence of l~M dose of NPY (18-36) (-) on forskolin stimulated cAMP production by SK-N-BE2 30 cells.
Figs. llA-llC show the analytical RPLC of ~30-31]
NPY (18-36) (llA), ~32-33] NPY (18-36) (llB), and t~33-34]
NPY (18-36) (llC).
Fig. 12 shows the inhibition of l25I-NPY binding 35 to rat cardiac ventricular membrane by NPY (0), NPY

WO9~/00161 ~ B ~ 2 U O PCT~S94/06837 ( 36) (-), [~ / ] NPY (18-36) (~), [~31/32] NPY (18 36) (-), and [~32/33] NPY (18-36) (~) Any number of analogs of the invention can be synthesized and tested in one or more of the assays are 5 described below or by methods which are known in the art.
We now describe preferred embodiments of the invention.
STRU~TURE
The sequences of naturally occurring NPY are described supra. As is easily observed, there is a high lO degree of amino acid homology between NPY and PYY.
The analogs of the invention have the general form~lla recited in the Summary of the Invention above .
The analogs of the invention are based upon the biologically active full-length molecule (amino acids 1-15 36) comprising amino acids of NPY and PYY and derivativesthereof; and upon the biologically act:ive subfragments comprising amino acids of NPY and PYY and derivatives thereof.
The analogs of the invention may have one or more 20 modifications to the NPY and PYY seque.nces (see above) .
For example, the compounds may have one or more of the following modifications which are useful for obtAining selective activity at a NPY receptor: a D-Trp or Aoc or D-Ala in place of one or two or three natural amino 25 acids; or a deletion of several N-terminal amino acids;
or the introduction of a pseudopeptide bond instead of a peptide bond between two adjacent amino acids. The analog is capable of acting as a competitive inhibitor of the naturally occurring NPY peptide by binding to the 30 receptor and, by virtue of one of the modifications described supra herein, fail to exhibi.t the biological activity of the naturally occurring peptide. For example, the peptides for which introduction of a pseudopeptide bond between two residues, or the 35 replacement of one or more natural ami.no acids with a D-WO95/00161 i PCT~S94/06837 ~,~652~ ~

Trp, or the deletion ("des") of the N-terminal residues or internal residues are useful in activity associated NPY activity.
The analogs of the invention can be provided in 5 the form of pharmaceutically acceptable salts. Examples of preferred salts are those with therapeutically acceptable organic acids, e.g., acetic, lactic, maleic, citric, malic, ascorbic, succinic, benzoic, or pamoic acid, as wells as polymeric acids and slats with 10 inorganic acids such as the hydrohalic acids, e.g., hydrochloric and sulfuric acids.
SYNTHESIS
Pe~tide Synthesis The compounds of the present invention , i.e., 15 compounds of formulas (I), (II), (III), (IV), and (V) may be synthesized by any t~chni~ues that are known to those skilled in the peptide art. Such tech~i ques are described in, e.g., Solid Phase Peptide Synthesis, eds, John M. Stewart and Janis D. Young, Pierce Chemical 20 Company, ~ockford, IL, 2nd edition.
The syntheses of the peptides listed in Table 1 and Table 2 were carried out as follows. Peptides were synthesized in an Applied Biosystems model 430A automated instrument, cleaved by hydrogen fluoride, and purified by 25 reversed phase chromatography as described by BalasubrA~n;~m et al. (Int . J. Pept . Protein Res . 29: 78-83, 1987; Pept. Res. 1:32-35, 1988). All synthetic peptides were >98% pure as determined by reverse phase chromatography and had the expected amino acid 30 composition and primary structure. Other analogs can be prepared by making appropriate modifications, within the ability of someone of ordinary skill in this field.
In addition, pseudopeptide bonds may, if desired, may be introduced at various positions, e.g., between 35 amino acid residues 31-32 of NPY(18-36) or between wo 95~00161 2 i 6 S ~ ~ ~ PCT~S94/06837 residues 32-33 of NPY(18-36), or of any peptide as described below. Despite the fact that optically pure Boc-AA-CHO can be obtained in good yields and coupled directly to the ~-NH2 group of the peptide resin by 5 published methods (Sasaki et al., Peptides 8:119-121, 1987; Fehrentz et al., Synthesis pp.676-678, 1983), this strategy has its limitations because of the possibility of brAnch; ng at the secondary amine group especially during the synthesis of long peptides with pseudobonds at 10 the ~-terminal region. Therefore the utility of several protecting groups, Z, Tos and Z(2-Cl), for capping the secondary amine group in the peptide resin was investigated. Although the reaction of the peptide resin with Z-Cl/Tos-Cl (2 equiv.) & DIEA (4 equiv.) completely 15 blocked the secondary amine, the known lability of Z-during repeated acidolysis to remove Boc group and the apparent resistance of Tos group to HF led us to choose Z(2-Cl) the secondary amine for capping. This is introduced by reacting the peptide resin with Z(2-Cl)-OSU
(2 equiv.), HOBT (2 equiv.) and DIEA (4 equiv.) for 10-60 min. The red wine color of ninhydrin with secondary amine turned yellow at the end of capping. This method yielded ~30/31]NPY(18-36), [~31/32]NPY~18-36) t~32/33]NPY(18-36) in greater than 65% yield as judged by 25 analytical HPLC. These peptides not only retained the antayonistic effect, but also exhibited increased affinity (20-220 times) and selectivity for cardiac NPY
receptors than NPY(18-36) as discussed below. Integrity of peptides cont~; n; ng pseudobonds were confirmed by mass 30 spectral analysis. Pseudopeptide bond-containing analogs - of NPY synthesized by these methods are listed in Table II. Protected amino acid derivatives (Peptide International, Louisville, KY) and peptide synthesis reagents (Applied Biosystems, Foster City, CA) were WO95/00161 ~ z~ PCT~S94/06~7 obtained commercially and used without further purification.

Examples of the synthesized analogs are:

Formula (I) ComPounds 5 tD-Trp lNPY Yra~ aAPAEDLARYYSALRHYlNLltD-Trp]RQRY-NH2 tD_Nal32~Npy ~aK~. __aAPAEDLARYYSALRHYlNLltD-NallRQRY-NH2 tD_phe32~Npy lra~rL~ APAEDLARYYSALRHYlNLltD-Phe~RQRY-NH2 tD-Hyp lNPY lraKPL: __aAPAEDLARYYSALRHYlNLltD-Hyp~RQRY-NH2 ~L Trp32~Npy ~ra~L: C_~APAEDLARYYSALRHYlNLllL-Trp~RQRY-NH2 1 0 Des AA7 24tD_Trp32~Npy YPSKPD------------------RHYINLl[D-Trp~RQRY-NH2 Des M7 24tD-Ala5 Aoc6 D_Trp32~Npy YPSKtD-Ala~tAoc~------------------RHYlNLltD-Trp~RQRY-NH2 Des AA7 24tAoc6~D_Trp32~upy 1 5 YPSKP UOc~----------------- Rhl I W-TrplRQRr-UH2 Formul~ ~11) Compounds tD-Ala28 D-Trp32~NPY~27-36) YtD-Ald NLltD-Trp~RQRY-NH2 Des-Asn29tD-Trp28~32~Npy~27 36) YtD-Trp~-LltD-Trp~RQRY-NH2 Formul~ ~111) ComPounds 2 0 cyclot7/21) Des M10~17tCys7 cys21 D-Trp32~Npy lraKPDCrll-------ARYCSALRHYlNLItD-Trp~RQRY-NH2 cyclo~7/2l)~ Des AA10 17lG~u7 LysZ' D-Trp32~NPy ~ra~ruE~G--------ARYKSALRHYlNLltD-TrplRQRY-NH2 Formul~ ~IV) Compounds 2 5 t 30/31lNPY ~18-36) -----------------ARYYSALRHYINL ITRQRY-NH2 t 31/32lHPY (18-36) -----------------ARYYSALRHYINLI TRQRY-NH2 t 32/33~NPY t18-36) -----------------ARYYSALRHYINLIT RQRY-NH2 ~o 95~00161 ~ 2 Q~ PCT~S94/06837 Other analogs of the invention ~can be prepared as above and tested for their biological activity effecl:iveness as antagonists or agonist:s using the methods described below and those commonly known in the 5 art.
FUNCTION~L ASSAYS
~ nimals Cell Lines and Cultures and Reagents Any suitable in vivo or in vitro system may be utilized to assay and test the effectiveness of the 10 compounds of the invention. Such assays may employ n vivo methods for evaluating physiologic:al responses, e.g., blood pressure, renovascular funotion, feeding behavior, or circadian rhythm, or in vivo biochemical systems evaluating receptor binding in a suitable cell 15 line, e.g., SK-N-MC (ATCC~HBT 10) or SR-N-BE(2) (Barnes et al. In Vitro 17: 619-631, 1981); or in isolated cells, e.g., cells isolated from the spleen, kidney, heart or brain. A number of in vivo and in vi~ro biochemical syste~s known to those skilled in the art are available 20 for testing antagonists to NPY receptors, e.g. the Y-1, Y-2, and Y-3 receptor categories. Described below are assay methods which can be utilized wi1h cell lines such as SK-N-MC and SK-N-BE2 or isolated cardiac membranes which possess the high-affinity NPY receptor sites Y-1, 25 Y-2, and Y-3, respectively. Other sysl_ems are also known for evaluating NPY antagonists to the '~-1 receptor, e.g.
VSM c~ells (Sheikh et al., ~n. J. Physiol . 260: G250-G257, 1991) and HEL cells (Motulsky et al. ~ner. J. Physiol.
255: E880-E885, 1988); Y-2 receptor, e.g., kidney (Sheikh 30 et al., Am. J. Physiol 26:F978-F984), spleen (Lunberg et al., Eur. J. Pharmal. 145:21-29, 1988), dorsal root ganglion (Bleakman et al., Br. J. Pha~al. 103:1781-1789, - 1991) and hippocampal cells (Sheikh et al., J. Biol.
Chem. 265:8304-8310, 1990); and Y-3 receptors, e.g., in 35 cardiac ve~lL~icular membranes (Balasubramaniam et al., WO95/00161 PCT~S94/06837 ~ ?~ 30 -Peptides 11: 545-550, 1990), chromaffin cells, rat gastric mucosa (Michel, M.C., Trends in Pharmol. sci . 12:
389-394, 1991) and brain stem.
In Vitro Biochemical AssaYs The ability of the compounds of the invention to act as antagonists of NPY can be demonstrated by any number of methods known in the art. For example, ~he compounds can be shown to compete with iodinated neuropeptide Y for receptors using the methods described 10 by Lundberg et al. (Eur. J. Pharmol. 145: 21-29, 1988);
Gordon et al.(~. Neurochemistry 55:506-513, 1990); Walker et al. (Mol. Pharmacol. 34:779-792, 1988);
Balasubramaniam et al. (Peptides 10:1283-1286, 1989), and others.
In one working example demonstrating antagonists to Y-l receptors, rat hypothalamus was isolated and the membranes were prepared for binding and adenylate cyclase studies according to st~n~rd methods (Unden et al. 1984.
Eur. J. Biochem 145: 525-530; Westlind-Danielsson et al.
20 1987. Neurosci. Lett. 74: 237-242). Displacement studies were performed in a total volume of 0.25 ml 20 mM HEPES
buffer, pH 7.4, cont~;n;ng 1~ bovine serum albumin, 0.1%
bacitracin, 300 ~m PMSF and 5 KIU/ml aprotinin. In a st~n~rd assay, 100 ~g of membrane/tube was incubated in 25 a ~h~k;ng water bath at 24 C for 45 min with [125I-Tyr1]-NPY (20,000 CPM) as described by Balasubramaniam et al (Peptides 11: 545-550, 1990) in the presence of increasing concentrations of NPY (10-11-10-5 M). At the end of incubation, 1.0 ml of iced cold buffer was added, 30 centrifuged at 10,000 X g for 10 min, and the supernatant removed by aspiration. The tube cont~;n;ng the pellet was counted for bound radioactivity in a mi~Lo~cdic gamma-counter.
An example of assaying adenylate cyclase activity 35 of hypothalamic and cerebral cortex membranes is now WO 95/00161 ~ 5~ ~ ~ PCT/US94/06837 described. Adenylate cyclase activity of the hypothalamic and cerebral cortex membranes was determined by incubating 50 ,lLg of membranes in a total volume of O.20 ml Tris-HCL 30 mM pH 7.4 buffer containing 150 mM
5 NaCl, 8.25 mM MgC12, 0.75 mM EGTA, 1.5 theophylline, 20 ,~Lg/ml aprotinin, 100 ,lLg/ml bacitracin, 1 mg/ml bovine serum albumin, 1 mM ATP, 20 mM creatine phosphate, mg/ml phosphocreatine kinase, 10 ,uM isopreternol, 10 ,uM
GTP, and various concentrations of peptides (0-10 ,uM).
10 After incubating the mixture at 35 C for 15 min in a ~h2~k;"g water bath, the reaction was arrested by the addition of 100 ,uM EDTA and boiling for 3 min. cAMP was extracted and quantitated by radioimmunoassay. All the points in the binding and adenylate cyclase are the means 15 of at least three parallel experiments performed in duplicate.
In one working example demonstrating antagonists to Y-3 receptors, rat cardiac ventricular membranes and iodination of NPY were prepared according to the method 20 described by Balasubramaniam et al. (Peptides 11: 545-550, 1990). Displacement studies were performed in a total volume of 0.25 ml of 20 I[M HEPES assay buffer, pH
7.6, cont~in;ng 2% bovine serum albumin, loo ~M
phenylmethylsulfonyl fluoride, 4 ,ILg/ml leupeptin, 4 ,~g/ml 25 chymostatin, 5 kallikrein-inactivating units/ml aprotinin, and 0.1% bacitracin. In a st~ rd assay, 200 ,~Lg of membrane protein/tube were incubated for 2 h at 18C in a shaking water bath with 125I-NPY (40 pM) and increasing concentrations of peptides. At the end of 30 incubation, tubes were vortexed and 150,u1 aliquots - transferred into polypropylene tubes cont~;n;ng 250 ~Ll of ice-cold assay buffer. Unbound 125I-NPY was separated by centrifugation at 10,000 x g for 10 min followed by aspiration of the supernatant. The tubes containing the 35 pellet were counted for bound radioactivity in a WO95/00161 PCT~S94/06837 ~ 2~ _ 32 -Micromedic y counter. The IC50 values were used to calculate the equilibrium dissociation constant, Ki for NPY and NPY antagonists using the equation Ki = IC50/(l +
F/Kd), where F and Ki denote the concentration and the S dissociation constant of l25I-NPY.
Adenylate cyclase activity was measured by Rosselin et al. (Biochim. Biophys. Acta 304:541-551, 1977). Each experiment was carried out in a total volume of 200 ~l solution cont~;ni~g 30 mM Tris-HCl, pH 7.4, 150 10 mM NaCl, 8.25 mM MgC12 0.75 mM EGTA, 1.5 mM theophylline, 20 ~g/ml aprotinin, 100 ~g/ml bacitracin, 1 mg/ml BSA, 1 mM ATP, 20 mM creatine phosphate, 1 mg/ml phosphocreatine kinase, 10 ~M isoproterenol, 10 ~M GTP, and various concentrations of peptides (0-10 ~M). The reaction was 15 initiated by the addition of 50 ~g (50 ~1) o~ membrane protein. After incubation at 35C for 10 min. in a ch~k;~g water bath, the reaction was terminated by the addition of 100 ~M EDTA and boiling for 3 min. cAMP was extracted and quantitated by radioimmunoassay using a kit 20 obtained from New England Nuclear, Boston, MA.
In Vivo Assays Any suitable n vivo model system can be used to evaluate the antagonistic properties of the compounds of the invention. Such models, without limitation, include 25 those used to evaluate feeding and memory behavior (Flood et al., Peptides 10:963-966), and vasoconstriction and hypertension (Balasubramaniam et al. Biochim et Biophys Acta 997: 176-188, 1989).
Thus, in one working example, f~e~;ng studies were 30 performed using Spraque Dawley rats (350-450 g) with paraventricular hypothalamic cannulae to investigate effects of NPY analogs (Ch~n~ et al. 1989. Peptides 10:
1283-1286). Antagonism of NPY induced feeding in rats was by ~D-Trp32]NPY. Groups of rats received 35 intrahypothalamic injections (1 ~l) of artificial CSF or ~095/00161 ~ 0 PCT~S94/06837 10 ~g of tD-Trp32]NPY. Fifteen minutes later CSF-treated rats were injected with CSF (n = 6), 1 ~g of NPY (n = 6) or 10 ~g of [D-Trp32]NPY (n = 7), while the rD-Trp32]NPY-treated rats were injected with 1 ~g of NPY (n = 8).
5 Rats were provided with a known c~uantit:y of rat chow, and after 1 hr the food consumed was determined and corrected for spillage a = p < 0.01 vs. CSF; b, not significant vs.
CSF; o~ = p < OoO1 vs. NPY; d = p < 0.05 vs. NPY.
In another working example blood pressure studies 10 were performed to evaluate the antagonistic properties of Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY. The method is as follows, after surgical preparation, three doses of NPY
(0.1, 1.0 and 10 nmol/kg) were a~in;~tered by intravenous push to 7 rats in a randomi,zed order. Each 15 dose ~as separated by a 20 minute washout period. After obt~;n;ng baseline systolic blood pressure (S8P) values, the rats received either 200 nmol/kg of' Des-AA7~24tD-Ala5, Aoc6, D-Trp32]NPY (n=5) or 0.9% saline (n=2) prior to each NPY dose. Change in SBP from basal st~te to maximum SBP
20 obser~ed following NPY was compared bet:ween baseline and Des-AA7~24~D-Ala5, Aoc6, D-Trp32]NPY treatments. The duration of SBP effect of Des-AA7 24[D-Ala5, Aoc6, D-Trp32]NPY was determined in 3 animals by administering 1.0 nmol/kg of NPY every 15 minutes for 75 minutes following 25 a single 200 nmol/kg dose of Des-AA7~24CD-Ala5, Aoc6, D-Trp ]NPY.

RESULTS
We first synthesized a series o~ full length analogs of NPY substituting either D-Trp or D-Trp(CH0) in - 30 the C-terminal receptor binding region at positions 32, 34 ancl 36. We tested for agonist acti~ity on isoproterenol-stimulated hypothalamic adenylate cyclase activity. Fig. 1 shows that at 1.0 ~M, NPY, tD-Trp34]NPY, ~D-Trp36]NPY, and the corresponding formulated D-Trp WO95/00161 PCT~S94/06837 ~ - 34 -analogs inhibited isoproterenol-stimulated hypothalamic adenylate cyclase activity significantly. [D-Trp32]NPY
and its formulated derivative, however, did not exhibit significant inhibitory effect on adenylate cyclase 5 activity at this concentration. In the binding experiments shown in Fig. 2, NPY and [D-Trp32]NPY
inhibited 125I-NPY bound to rat hypothalamic membranes in a dose-dependent manner with IC50 values of 0.63 nM and

3.0 nM, respectively. It is this high receptor activity 10 and the complete loss of intrinsic activity that suggests that [D-Trp32]NPY may be an antagonist of NPY in rat hypothalamus.
The complete loss of intrinsic activity, while retaining high binding potency suggested that [D-Trp32]NPY
15 may be an antagonist of NPY in hypothalamus. In order to further substantiate this observation, we investigated the inhibitory effect of NPY on rat hypothalamic membrane adenylate cyclase activity both in the absence and presence of tD-Trp32]NPY. Fig. 3 shows that NPY inhibited 20 isoproterenol st;~lllAted hypothalamic membrane adenylate cyclase activity dose-dependently with an IC50 value 0.18 nM. tD-Trp32]NPY did not exhibit any inhibitory effect on adenylate cyclase activity. Further, Fig. 3 shows that the presence of 30 and 300 nM tD-Trp32]NPY shifted the 25 inhibitory dose-response curve of NPY on hypothalamic adenylate cyclase activity to the right increasing that IC50 value to 4.0 nM (KB = 1. 41 nM) and 540. nM (KB = 1. 36 nM), respectively.
To assess the specificity of [D-Trp32]NPY, we 30 investigated its effect on the inhibitory hypothalamic adenylate cyclase activity of serotonin. Fig. 4 shows that the presence of serotonin (100 nM) significantly (p < 0.01; by repeated measures ANOVA) inhibited the isoproterenol stimulate adenylate cyclase activity both 35 in the absence and presence of [D-Trp32]NPY (1 ~M). The wo 95~00161 ~1 B~ PCT~S94/06~7 .

antagonism at [D-Trp32]NPY, therefore, was specific to the NPY receptor since the analog exhibite~ no effect on the inhibitory hypothalamic AC activity of serotonin and, thus, did not act as a global antagonist.
Since hypothalamic NPY has been shown to elicit a feeding response, we also investigated the effect of tD-Trp32]NPY on NPY induced feeding in freely moving rats.
Fig. ~ shows that intrahypothalamic in-Jection of NPY (1 ~g) s:ignificantly (p < O.01) stimulated the cumulative lO food :intake as compared to vehicle (art;ificial cerebrospinal fluid) treatment over 1 hr. On the other hand, [D-Trp32]NPY (1 ~g) did not stimulate feeding significantly over this period, nor dicl it attenuate NPY
(1 ~g~ - induced feeding at this concentration. lO ~g of tD-Trp32]NPY also did not exhibit significant effect on f~;mg, and at this dose significantly (p < 0.05) attenuated the 1 hr. cumulative food intake induced by 1 ~g of NPY. All of these observations suggest that D-Trp32 is a specific and competitive antagonist at NPY in rat 20 hypot~halamus in both in vitro and in vivo models.
In order to improve the potency and/or selectivity, several analogs were synthesized substituting the residue at 32 with various amino acids, e.g., D-Nal, D-Phe, D-Hyp, or L-Trp (F:ig. 6). However, 25 these analogs exhibited agonistic acti~ity which suggests there are strict structural requirements to induce antagonistic properties to NPY. Although it is generally believed that the NPY effects on blood pressure and feeding are mediated by the Y-1 receptor subtype, it is 30 possible that NPY analogs which elicit pressor effects have no orexigenic effects. Thus, [D-Trp32]NPY is useful not only to elucidate the receptor subtypes mediating NPY
effects on hypothalamus, but also to determine whether feeding and pressor effects are mediated by the Y-l 35 receptors.

WO95/00161 PCT~S94/06837 ~5~Q 36 -Next, the relative binding affinities of various compounds having formula (I) were investigated using SK-N-MC (Y-1) and SK-N-BE2(Y-2) shown in Table I. These studies led to the development of two truncated peptide 5 analogs, Des-AA7~24[Aoc6, D-Trp32]NPY and Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY, which did not inhibit the cAMP
production by SK-N-MC cells (see Table I). However, Des-AA7-24[Aoc6, D-Trp32]NPY exhibited poor affinity to Y-1 receptors (Table I), and therefore, failed to antagonize 10 the inhibitory effects of NPY on SK-N-MC cAMP production.
On the other hand, Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY, surprisingly exhibited moderate affinity (Table I), and its presence (1.0 ~M) shifted the inhibitory dose-response curve of NPY on SK-N-MC cAMP production parallel 15 to the right (Fig. 7). These observations confirm that Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY is a competitive antagonist of NPY in Y-1 receptors.
To investigate whether these compounds ret~i n~
antagonistic activity within an in vivo model, we tested 20 the effects on NPY-induced anorectic rats. Fig. 8 shows that NPY doses of 0.1, 1.0 and 10.0 nmol/kg, during baseline, increased systolic blood pressure (SBP) by 8+7, .26+6 and 37+7 mmHg respectively. Following administration of Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY, NPY
25 doses of 0.1, 1.0 and 10.0 nmol/kg increased SBP by 4+5, 9+5 and 29+17 mmHg respectively. The change in SBP
during Des-AA7-24~D-Ala5~ Aoc6 D_Trp32]Npy significantly different than baseline values (p z 0.0002 at the 1.0 nmol/kg NPY doses, but not at the 0.1 or 10 30 nmol/kg doses. Changes in SBP in control rats receiving saline were not significantly different than baseline values at all NPY doses. The duration of effect of the antagonist ranged between 30-75 minutes. This result demonstrates that Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY is 35 effective in attenuating NPY induced vasoconstriction Ln ~095/00161 21 ~ S ~ ~ ~ PCT~S94/06837 vivo. Its ability to only affect SBP at the middle NPY
dose aLnd the f ind ing that Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY can inhibit the binding of 125I-NPY to SK-N-MC
cells, suggests that Des-AA7~24tD-Ala5, Aoc6, D-Trp32]NPY
5 compet:itively antagonizes NPY induced hypertension.
In addition, further truncation and deletion of Des-AA7~24[D-Ala5, Aoc6, D-Trp32]NPY resulted in the development of three analogs (Table I). Although these analogs did not bind to Y-2 receptors, both ~D-Ala28], D-10 Trp32]NPY(27-36) and ~Bip27, D-Ala28, D_Trp32]Npy(27-36) also exhibited poor affinity to Y-1 receptor. However, Des-Asn29tD-Trp28~32]Npy(27-36) bound with moderate potency to Y-l receptors, and also did not exhibit any intrinsic activity on isoproterenol stimulated cAMP
15 production by SK-N-MC cells. These observations suggest that Des-Asn29tD-Trp28~32]NPY(27-36) or its analogs will prove useful for the development low molecular weight æelective antagonist compounds for Y-l receptors.
TABLE I
20 Peptides IC50 (nM) for the inhibition of 125I_Npy binding to (Y-1) (Y-2) NPY 1.3 0.1 [D-Trp ]NPY 1000 0.63 Des-AA7~24tAOc6~D-Trp32]Npy 3900 10.0 De.s-AA7~24 ~3 D-Ala5 Aoc6,D-Trp 2]NPY 100 1.0 [D-Ala23, D-Trp32]NPY(27-36) 630 N.I.
~Bip272 D-Ala28, D-Trp3 ]NPY(27-36) 1300 N.I.
Des-Asn29 [D-Trp23~32]NPY(27-36) 170 N.I.

35 N.I.: no inhibition even at 10,000 nM

W095/0016~s~Q~ PCT~S94/06837 The analogs of the invention may also be assayed and tested for NPY receptor Y-2 activity using the methods described supra. Thus, a compound, e.g., tD-Trp32]NPY, can be assayed for antagonism using any Y-2 5 receptor bearing cell, e.g., the SK-N-BE2 cell line, or such cells found in the spleen, kidney, hippocampus or dorsal root ganglion.
Towards developing selective agonists and antagonists of Y-2 receptors, we tested a number of 10 compounds using SK-N-BE2 cell lines. These studies demonstrated that NPY(18-36), previously shown to be an antagonist of NPY in rat cardiac membranes bearing Y-3 receptors, antagonizes the inhibitory effect on the cAMP
production of SK-N-BE2 cells bearing Y-2 receptor 15 subtypes as shown in Figures 9 and 10.
NPY R~10K (Y-3 ~u~ Y~) Next, we investigated the effect of introducing a pseudopeptide bond to NPY*18-36). Table II shows the results for the increased affinity and selectivity of 20 pseudopeptide analogs of NPY(18-36) for Y-3 receptors.
The introduction of pseudobonds (-CH2NH-) at positions 31-32 or 32-33 of NPY(18-36) was found to substantially increase Y-3 receptor affinity (see Table 2). Subsequent experiments revealed that all these analogs retain their 25 antagonistic properties. Furthermore, [~30/31]NPY(18-36) and [~31/32]NPY(18-36) and [~32/33]NPY(18-36) analogs exhibit lower affinity to Y-1 and Y-2 subtypes than NPY(18-36) (Table II). Thus, introduction of pseudobonds at 32-33 and 31-32 also increases their selectivity for 30 Y-3 receptors.

~O~ 95/00161 ~ 2 ~ ~ PCT/US94/06837 TABLE II
A

ES IC50 (n~) for the inhibition of 125I-NPY binding tos (CARDIAC) (SK-N-BE2~ (SK-N-NC) NPY 0.20 0.1 1.3 NPY (18--36) 126 3.00 251 [~32-33]NPY(18-36) 0.56 158 1585 [~31-32]Npy (18--36) 1.00 562 1995 10 ~!3-31]NPY(18--36) 6.00 281 N.D.

9! , -CII2NH- ; N . D ., not determined.

EXANP~E~
This invention is further illustrated by the 15 following nonlimiting examples.

8ynth~8i8 of ~D--Ala5, Aoc6, D--Trp32~NPY
Peptide Synthesis -- MBHA resin (0. 45 mM NH2 group) was placed in a reaction vessel of the Applied Bioscience (ABI) 430A automated in~L~ul..cnt and amiLno acid derivatives were coupled automatically using the st~n~A~d -am provided by the manufacturer modified to incorporate a double coupling procedure. All amino acids were coupled using 2.2 equivalents of preformed 25 symmeltrical anhydrides. Arg, Asn and C;ln, however, were coupled as preformed l-HOBT esters (4.4 equal.) to avoid deamidation or lactam formation. At the end of the WO95/00161 PCT~S94/06837 2~

synthesis N-~-Boc-group was removed and peptide resin (~lg) was treated with HF as described below.
In the reaction vessel 1.0 g peptide resin, 0.8 g p-cresol, 0.2g thiocresol, 0.8 ml (CH3) 2 and 5 ml HF
5 were stirred for 40 min of reaction and an additional 60 min. of HF evacuation. During these procedures temperature of reaction vessel was kept between 0C - ~
4OC. Then the peptide resin was transferred into a fitted filter funnel in Et20 and washed with excess of 10 Et20. Free peptide was extracted with 30% HOAc (2xl5ml).
Peptide solution was diluted to 10% HOAc (60ml H20) and lyophilized. 390 mg crude peptide was obtained from this procedure.

EXAMP~E 2 15 8ynthesis Of tD-Trp32] NPY
Peptide synthesis was performed as described above.
Cleavage by HF was as follows: in a reaction vessel 1.0g peptide resin, 0.8 ml (CH3)C2S, 0.8g p-cresol, 0.2g p-thiocreosl and 5ml HF were stirred for 40 min of reaction 20 in temperature between 0C - -4C. After that HF was evacuated in 60. Temperature was still kept below 0C.
The peptide resin was transferred into fitted filter funnel and washed with e~ces~ of ET20. The peptide resin extracted with 30ml 30% HOAc. Peptide solution was 25 diluted to 10% HOAc with 60ml H2O and protein lyophilized. Total weight of crude peptide: 190mg.

8ynth~ of Cyclo~7/21), De3-AAl0-l7tcys7~2l~D-Trp32] NPY
Peptide synthesis was as described above using an 30 Automated ABI 430A synthesizer. The free peptide was ob~; nP~ by treating the protected peptide resin (1.0g) with HF (10 ml) containing dimethyl sulfide (0.8 ml), p-cresol (0.2g) for 1 h at -2 to -4 C. The residue was ~095/00161 ~1 ~ 5 ~ ~ ~ PCT~S94/06~7 transferred to a fitted filter funnel with diethyl ether, washed repeatedly with diethyl ether, and the peptide extracted with 10~ HOAC(2X 15 ml) and lyophilized. The crude peptide (100mg) thus obtained was dissolved in 6M
5 guanidine HCL (6 ml) diluted with 500 ml of distilled water and the pH adjusted to 8 with ammonia. A solution of potassium ferricyanide (1% w/v) was gradually added with constant stirring until a yellow color persisted.
After stirring for an additional 30 min., the pH of the 10 solution was adjusted to 5 with acetic acid and the solution stirred with an anion exchange resin (AG-3, Cl-form, 10g wet weight) for 30 min, passed through a 0.45 microns filter, and pumped into a semipreparative column (250X10 mm), washed with 0.1%TFA-H20 u~ntil a flat base 15 line was obtained. The column containing the peptide was then subjected to gradient elution as described for NPY, and the purified peptide was characterized by amino acid and mass spectral analysis.

EXAMPLE ~
20 8ynthesis of Cy¢1O~7/21), Des-AAl0-l7tGlu7~ Lys21, D-Trp32 INPY
The synthesis of this peptide was accomplished using the general strategy described for NPY except for the following: After coupling BocGlu(OFM) at position 7, the 25 side chain protecting groups, ~-Fmoc group at Lys2l and the ~ORm of Glu7 were removed by removing the peptide resin with 20% piperidine-DMF. After repeated w~hings with DMF, the ~-NH2 group of Lys21 was coupled to y-COOH
of Glu7 by stirring the peptide resin with BOP-HOBT-DIPEA
(1:1:3) in DMF (20 ml) overnight, and if cyclization is not complete as judged by the standard ninhydrin test the procedure was repeated until complete ~yclization has occurred. The synthesis was then continued in the WO95/00161 ~ 2 9 ~ PCT~S94/06837 automated mode, and the free peptide was obtained by the standard HF method described in Example 3.

Bxample S
8ynthesis of [~32/331NPY (18-36) St~n~rd techniques, as described above, were employed for the solid phase synthesis of the carboxy terminal portion of cardiac receptor antagonist, NPY
t~32/33]NPY (18-36), up to the point at which introduction of the pseudopeptide bond was desired. The pseudopeptide 10 ~ond was then introduced in the analog according to the method of Sasaki et al. (Peptides 8:119-121, 1986) , with Boc as the protecting group for the primary amine.
The resulting N-~-Boc-peptide-resin with the pseudopeptide bond (0.25 mmol) was swollen in DMF (10 ml) 15 for 10 min in a two-necked R.B. flask fitted with a drying tube. This was followed by the addition of diisopropylethyl amine (1.0 mmol), HOBt (0.5 mmol) and Z(2-Cl)OSU (0.5 mmol). HOBt enhances the coupling of Z(2-Cl) to the secondary amino group of the pseudopeptide 20 bond. The reaction mixture was stirred at room temperature until the Kaiser's ninhydrin test gave a yellow color indicating that the secondary amine had been blocked. The peptide resin was returned to the reaction vessel of the automated peptide synthesizer and the rest 25 of the sequence was assembled automatically. The free peptide was obtained by the standard cleavage conditions and purified by reverse phase chromatography.

USE
Because NPY is a potent vasoconstrictor and or 30 orexigenic agent, as well as an inhibitor of libido and effector of circulation rhythm, it is likely that the administration of one or more compounds of the invention may ~u~ess or inhibit the deleterious effects of NPY.

9~00161 ~ t 6 ~ 00 PCT~S94/06837 ~0 Therefore, the NPY antagonists of the invention are suitable for the treatment of any number of diseases relate.d to cardiovascular function (e.g., congestive heart failure or hypertension), obesity, anorexia, blood 5 pressure, asthma, pulmonary hypertensicn, renal hypertension, memory retention, sexual dysfunction (e.g.
impotence), and disorders involving sleep and circ~ n rhythDls. For example, the compounds of formula (I), (II), (III) are useful for treating for controlling lO feeding disorders and blood pressure; t:he compounds of formula (IV) are useful for treating any number of heart ailments, e.g., chronic heart failure, as well as promot:ing recovery from ischemia since the compounds are expected to enhance myocardium contract:ion; and the 15 compounds of formula (IV) are useful for controlling NPY
actions mediated by Y-2 receptor subtypes, e.g., for controlling the effects of NPY on rena] blood flow, glomerular filtration rate, natriuresis and renin secre1:ion.
Thus to treat the above disorders, the appropriate NPY antagonist is administered as a therapeutic preparation (as described below) in acc:ordance with the condi1:ion to be treated. In the practice of the method of the present invention, an effective amount of an NPY
25 antagonist, e.g., ~3O-3lNPY(l8-36), is a~;nictered via any of the usual and acceptable methods known in the art, either singly or in combination with another compound or compounds of the present invention. These compounds or compositions can thus be administered orally, 30 sublingually, parenterally (e.g., intramuscularly, intravenously, subcutaneously, or intradermally) or by ~nh~l~tion, and in the form or either solid, licluid or gaseous dosage, including tablets and suspensions. The a~; n i ~tration can be conducted in a single unit dosage WO95/00161 PCT~S94/06837_ ~J~52~ ~ ~

form with continuous therapy or in a single dose therapy ad libitum.
The dose of the compound of the present invention for treating the above-mentioned disorders varies 5 depenA;ng upon the manner of a~min;~tration, the age and the body weight of the subject, and the condition of the subject to be treated, and ultimately will be decided by the att~n~ing physician or veterinarian. Such amount of the active compound as determined by the att~n~ing lO physician or veterinarian is referred to herein as a "therapeutically effective amount". Thus, a typical administration is oral administration or parenteral administration. The daily dose in the case of oral administration is typically in the range of O.1 to lO0 15 mg/kg body weight, and the daily dose in the case of parenteral administration is typically in the range of O.OO1 to 50 mg/kg body weight.
To be effective for the prevention or treatment of the above-mentioned disorders it is important that the 20 therapeutic agents be relatively non-toxic, non-antigenic and non-irritating at the levels in actual use.
It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof 25 will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.
Other embodiments are within the following claims.

Claims

1. A compound having the formula:

(I) wherein each R1 and R2, independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl;
A1 is Tyr, or any aromatic amino acid;
A2 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal or Asp;
A3 is Ser, Thr, N-Me-Ser, N-Me-Thr,Ile, Val, Aib, Anb, Nle, or N-Me-Leu;
A4 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A5 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, or D-Trp;
A6 is Gly or is the D- or L- isomer selected from the group consisting of Asp, Glu, N--Me-Asp, Ala, or Aoc;
Y is A7-A8-A9-A10-A11-A12-A13-A14-A15-A16-A17-A18-A19-A20-A21-A22-A23-A24 or is absent, where A7 is Asn, Ala, Gln, Gly, or N-Me-Asn;
A8 is Pro, Ser, Thr, Hyp, D-Ala, N-Me-Ala, Ac6c, or D-Pal;
A9 is Gly, N-Me-Gly, Ala, or Trp;
A10 is Glu, Asp, N-Me-Glu, Ala, or Nva;
A11 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A12 is Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A13 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, N-Me-Ala, or Thr;

A14 is Ala, Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A15 is Glu, Asp, N-Me-Glu, Ala, or Nva;
A16 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A17 is Met, Leu, Ile, Val, Aib, Anb, Nle, or N-Me-Leu;
A18 is Ala, Asn, Gln, Gly, N-Me-Asn, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A19 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys--NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A23 is Ala, Ser, Thr, Nal, Thi, Phe, Bth, Pcp, N-Me-Ala, N-Me-Ser, or N-Me-Thr;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys--NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A26 is the D- or L- isomer of selected from the group consisting of His, Thr, 3-Me-His, .beta.-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys--NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;

A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring;
A28 is Aib or is the D- or L- isomer sel.ected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn, or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;
A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring, Ant, Ser, N-Me-Ser, Thr, N-Me-Th.r, Ala, N-Me-Ala, D-Hyp, or any Trp derivative;
A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-6-NH-R (where R is H, a, branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A36 is Tyr, or any aromatic amino acid;
W is -OH, -N-R3R4, or OR5 (where each R3, R4, and R5 , independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-G18 alkaryl; wherein, in formula (I) each bond can represent either a peptide bond or a pseudopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.

2. The compound of claim 1, wherein Y (A7-A24) is absent.

3. The compound of claim 2, wherein said compound has the formula Des AA7-24, Aoc6 D-Trp32] NPY.

4. The compound of claim 2, wherein said compound has the formula Des AA 7-24 [D-Ala5, Aoc6, D-Trp32] NPY.

5. A compound having the formula:

(II) wherein X is a chain of 0-7 amino acids, inclusive, the N-terminal one of which is bonded to each R1 and R2;
wherein each R1 and R2, independently, is each H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl;
A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring;
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, or N-Me-Asn, or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu, or is deleted;
A31 is Ile, Cys, D-Ala, Leu, Val, Aib, Anb, or N-Me-Ile, or is deleted;
A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring, Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative;

A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A36 is Tyr, or any aromatic amino acid;
W is -OH, -N-R3R4, or OR5 (where each R3, R4, and R5 , independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 alkaryl or C7-C18 alkaryl; wherein, in formula (II) each bond can represent either a peptide bond or a pseudopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.

6. The compound of claim 5, where X is A20-A21-A22-A23-A24-A25-A26 wherein A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me-Thr;
A23 is Ala, Ser, Thr, Nal, Thi, Phe, Bth, Pcp, N-Me-Ala, N-Me-Ser, or N-Me-Thr;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;

A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, .beta.-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R
(where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
W is -OH, -N-R3R4, or OR5 (where each R3, R4, and R5 , independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl;
or a pharmaceutically acceptable salt thereof.

7. The compound of claim 5 having the formula [D-Ala28, D-Trp32]NPY (27-36).

8. The compound of claim 5, having the formula Des-Asn29 [D-Trp28,32]NPY(27-36).

9. A compound having the formula:

-A25-A26-A27-A2s-A2s-A30-A31-A32-A33-A34-A35-A36-W (III) wherein a disulfide bond is between A7 and A21 or is absent; wherein each R1 and R2, independently, is H, C1-C12 alkyl, C6 C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl;
A1 is Tyr, or any aromatic amino acid;
A2 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal or Asp;
A3 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ile, Val, Aib, Anb, Nle, or N-Me-Leu A4 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, LYS-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A5 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, or D-Trp;
A6 is Gly or is the D- or L- isomer selected from the group consisting of Asp, Glu, N--Me-Asp, Ala, or Aoc;
A7 is Cys, Glu, Asn, Ala, Gln, Gly, or N-Me-Asn;
A8 is Pro, Ser, Thr, Hyp, D-Ala, N-Me-Ala, Ac6c, or D-Pal;
A9 is Gly, N-Me-Gly, Ala, or Trp;

Y is A10-A11-A12-A13-A14-A15-A16-A17 or is absent, where A10 is Glu, Asp, N-Me-Glu, Ala, or Nva;
A11 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A12 is Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A13 is Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, N-Me-Ala, or Thr;
A14 is Ala, Pro, Hyp, D-Ala, N-Me-Ala, Ac6c, D-Pal, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A15 is Glu, Asp, N-Me-Glu, Ala, or Nva;
A16 is Asp, Glu, N-Me-Asp, Ala, or Anb;
A17 is Met, Leu, Ile, Val, Aib, Anb, Nle, or N-Me-Leu;
A18 is Ala, Asn, Gln, Gly, N-Me-Asn, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A19 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;

A20 is Tyr, or any aromatic amino acid;
A21 is Cys, Lys, Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A23 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, .beta.-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring;
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn, or deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;
A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring, Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative;
A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from, the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A36 is Tyr, or any aromatic amino acid;
W is -OH, -N-R3R4, or OR5 (where R3, R4, and R5 , independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl; wherein, in formula (III) each bond can represent either a peptide bond or a pseudopeptide bond, provided that said compound cannot contain more than 3 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.

10. The compound of claim 9, having the formula cyclo(7/21), Des AA10-17[Cys7, Cys21, D-Trp32]NPY.

11. The compound of claim 9, having the formula cyclo(7/21), Des AA10-17[Glu7, Lys21, D-Trp32]NPY.

12. A compound with pseudopeptide bonds having the formula:

A32-A33-A34-A35-A36 - W (IV) wherein each R1 and R2, independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl;

A18 is Ala, Asn, Gln, Gly, N-Me-Asn, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A19 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A20 is Tyr, or any aromatic amino acid;
A21 is Tyr, or any aromatic amino acid;
A22 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala A23 is Ser, Thr, N-Me-Ser, N-Me-Thr, Ala, Nal, Thi, Phe, Bth, Pcp, or N-Me-Ala;
A24 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A25 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A26 is the D- or L- isomer selected from the group consisting of His, Thr, 3-Me-His, .beta.-pyrazolylalanine, N-Me-His, Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys-.epsilon.-NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A27 is the D- or L- isomer selected from the group consisting of any aromatic amino acid, Lys, or a tethered amino acid with an indole ring;
A28 is Aib or is the D- or L- isomer selected from the group consisting of Ile, Leu, Val, Anb, Trp, N-Me-Ile, or is deleted;
A29 is Asn, Ala, Gln, Gly, N-Me-Asn, or is deleted;
A30 is Leu, Ile, Val, Aib, Anb, or N-Me-Leu;
A31 is Ile, Cys, Leu, Val, Aib, Anb, or N-Me-Ile;

A32 is the D- or L- isomer selected from the group consisting of any aromatic amino acid except L-Tyr, a tethered amino acid with an indole ring, Ant, Ser, N-Me-Ser, Thr, N-Me-Thr, Ala, N-Me-Ala, D-Hyp, or any Trp derivative;
A33 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys--NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), Orn, or is deleted;
A34 is Gln, Asn, N-Me-Gln, Nle, Nva, Ala, or Gly;
A35 is the D- or L- isomer selected from the group consisting of Lys, Arg, homo-Arg, diethyl-homo-Arg, Lys--NH-R (where R is H, a branched or straight chain C1-C10 alkyl group, or a C6-C18 aryl group), or Orn;
A36 is Tyr, or any aromatic acid;
W is -OH, -N-R3R4, or OR5 (where R3, R4, and R5 , independently, is H, C1-C12 alkyl, C6-C18 aryl, C1-C12 acyl, C7-C18 aralkyl, or C7-C18 alkaryl;
wherein, in formula (IV) each bond can represent either a peptide bond or a pseudopeptide bond, provided that said compound cannot contain more than 2 pseudopeptide bonds, or a pharmaceutically acceptable salt thereof.

13. The compound of claim 1, 5, 9, or 12, wherein a pseudopeptide bond is positioned between A29 and A30.

14. The compound of claim 1, 5, 9, or 12, wherein a pseudopeptide bond is positioned between A30 and A31.

15. The compound of claim 1, 5, 9, or 12, wherein a pseudopeptide bond is positioned between A31 and A32.

16. The compound of claim 1, 5, 9, or 12, wherein a pseudopeptide bond is positioned between A32 and A33.

17. The compound of claim 1, 5, 9, or 12, wherein a pseudopeptide bond is positioned between A34 and A35.

18. The compound of claim 1, 5, 9, or 12, wherein a pseudopeptide bond is positioned between A35 and A36.

19. A dimeric compound comprising one compound from either claims 1, 5, 9, or 12 and one compound from either claims 1, 5, 9, or 12, wherein said dimer is formed by either an amide bond or a disulfide bridge between the two compounds.