WO1993013126A1

WO1993013126A1 - Peptide compounds having therapeutic activity

Info

Publication number: WO1993013126A1
Application number: PCT/GB1992/002369
Authority: WO
Original assignee: Fisons Corporation; Fisons Plc
Priority date: 1991-12-20
Filing date: 1992-12-21
Publication date: 1993-07-08
Also published as: EP0619823A1; FI942898A; FI942898A0; JPH08500324A; CA2126236A1; NO942350L; HU211564A9; MX9207458A; IL104161A0; NO942350D0; NZ246195A; AU3167893A; AU672186B2

Abstract

Compounds of formula (I), wherein R1 is OH or OSO¿3?H; M is Met, Ahx or Ile; G is Gly or Sar; X is Met, Ahx, Ile, Phe or Lys(R?2¿); J is Asp, Asp(OBn), DAsp, MeAsp, or MeDAsp; and L is Phe or MePhe; with various provisos; and pharmaceutically acceptable derivatives thereof; are useful as therapeutic agents, in particular in the inhibition of feeding.

Description

Peptide compounds having therapeutic activity

This invention relates to peptide compounds having therapeutic activity (in particular feeding inhibition), their use as pharmaceutical and cosmetic therapeutic agents, and s formulations comprising them.

CCK-8 (a peptide having the structure Asp-Tyr(S0₃H)-Met-Gly-T -Met-Asp-Phe-NH₂) is known to have feeding inhibition properties [see for example J E Morley, Minireview: 'The ascent of cholecystokinin - from gut to brain', Life Sciences, vol 30 (6), pp479-493, o 1982].

International Patent Application WO 91/08225 (to Fisons Corporation) discloses a number of peptide compounds which are indicated for use in the inhibition of feeding.

s A group of peptide compounds have now been found which are particularly advantageous.

According to the present invention, there is provided a compound of formula I:

wherein

R¹ is OH or OS0₃H;

M is Met, Ahx or He;

G is Gly or Sar;

X is Met, Ahx, He, Phe or Lys(R²);

J is Asp, Asp(OBn), Dasp, MeAsp, or MeDAsp;

L is Phe or MePhe;

R² is a group of formula II,

wherein E is NH, CH=CH or CH₂CH₂; and R³, R⁴, R^s, R⁶ and R⁷ are independently H, OH, halogen, alkyl C^ or OS0₃H; provided that when R^l is OS0₃H, G is Gly and: (a) J is Asp, L is MePhe and M is Ahx, then X is not Ahx; (b) J is Asp, L is MePhe and M is lie, then X is not He;

(c) J is Asp, L is MePhe and M is lie, then X is not Ahx;

(d) J is Asp, L is Phe and M is Met, then X is not Met;

(e) J is Asp, L is MePhe and M is Met, then X is not Met;

(f) J is Dasp, L is MePhe and M is Met, then X is not Met; or a pharmaceutically acceptable derivative thereof (hereinafter referred to en bloc as "the compounds of the invention").

The compounds of the invention, amino acids, peptides and protecting groups are represented by symbols commonly used in the art, for example those defined by IUPAC and lUB.

All optically active amino acids have the L-configuration unless otherwise indicated.

Examples of symbols are given below:

Ahx 2-aπώιohexanoic acid

Asn asparagine

Asp aspartic acid

Asp(OBn) aspartic acid beta-benzyl ester Asp(OtBu) aspartic acid beta-tert-butyl ester

Boc tert-butyloxycarbonyl

BrCH₂-Pam 4-(bromomethyl)phenyl-acetamidomethyl

DAsp D-aspartic acid

Tyr(S0₃H) O-sulphotyrosine

Thus, Hpa(S0₃H)-Met-Gly-Trp-Met-Asp-MePhe-NH₂ is the compound of formula I in which R¹ is OH, M is Met, G is Gly, X is Met, J is Asp and L is MePhe:

By Lys(R²) we mean a lysine residue in which the ε-amino group forms an amide bond with a group of formula II, as defined above. Two particular groups of formula II which may be mentioned are the group in which E is NH, R³ is methyl and R^4"7 are each hydrogen, ie (2-methylphenyl)aminocarbonyl, also referred to herein as 'Tac"; and the group in which E is

R⁵ is OH and R³, R⁴, R⁶ and R⁷ are each hydrogen.

Pharmaceutically acceptable derivatives of the compounds of formula I include esters and amides of any carboxylic acid groups which may be present, and pharmaceutically acceptable salts. Pharmaceutically acceptable derivatives which may be mentioned include unsubstituted amides of carboxylic acid groups (for example Asp may be present as its unsubstituted amide derivative Asn) and alkyl C_w (for example methyl) esters of carboxylic acid groups. Pharmaceutically acceptable salts which may be mentioned include sodium and ammonium salts. Pharmaceutically acceptable derivatives of compounds of formula I may be prepared from the corresponding compound of formula I by conventional methods.

The term "pharmaceutically acceptable" used herein should be construed to mean that the compound, derivative, salt or other substance to which it refers is suitable for administration to the body as a pharmaceutical or cosmetic therapeutic agent. Similarly, terms such as "use as a pharmaceutical" and "pharmaceutical formulation" include use as a cosmetic therapeutic agent and a cosmetic therapeutic formulation respectively.

Preferably M is Ahx or He; G is Gly; X is Ahx, He or Lys(R²); J is Asp, Dasp, MeAsp or MeDAsp; and R¹ is OS0₃H.

According to a further aspect of the invention, there is provided a process for the preparation of a compound of formula I, or a pharmaceutically acceptable derivative thereof which comprises: a) sulphating a compound of formula III,

wherein M, G and L are as defined above; Ja has the same definition as J above, except that the /3-carboxyl group of any Asp, Dasp, MeAsp or MeDAsp residue present is optionally protected; Xa has the same definition as X above, except that it may additionally represent Lys and any hydroxy or amino group is present in protected form (except for any hydroxy groups to be converted to a sulphate ester); and Za is NH₂ or a carboxyl protecting group; b) removing one or more protecting groups from a compound of formula IV,

wherein R\ M, G, Xa, Ja, and Za are as defined above, and at least one of Xa, Ja, and Za comprises a protecting group; c) reacting a compound of formula V,

wherein M, G, J and L are as defined above, and Xb is Lys, with a compound of formula VI,

V I

wherein R³, R⁴, R⁵, R⁶ and R⁷ are as defined above, to give a corresponding compound of formula I in which X is Lys(R²) and E is NH; or d) coupling a compound of formula V as defined above with a compound of formula VII,

wherein E is CH₂CH₂ or CH=CH and R³, R\ R⁵, R⁶ and R⁷ are as defined above, to give a corresponding compound of formula I in which X is Lys(R²) and E is CH₂CH₂ or CH=CH.

The invention provides intermediate compounds of formula WVperse.

In process (a), the sulphating agent may be, for example, sulphur trioxide or a complex thereof, such as sulphur trioxide pyridine. We particularly prefer to carry out the sulphation in a polar aprotic solvent, for example, dimethylfoπnamide or pyridine. The reaction is preferably carried out using an excess of sulphating agent, for example a 1-40 molar excess, preferably a 5 molar excess.

In processes (a) and (b), protecting groups for peptides and methods for their removal are well known in the n , see for example, T W Greene, Protective Groups in Organic Synthesis, Wiley-Interscience (1981). The choice of protecting groups and the methods employed for their removal will depend, inter alia, on the method of synthesis employed for the preparation of the peptide and the amino acids in the peptide. Suitable amino protecting groups include, for example, benzyloxycarbonyl, which may readily be removed by hydrogenolysis or hydrogen bromide in acetic acid; t-butyloxycarbonyl, (Boc), which is removed by standing the peptide in cold trifluoroacetic acid; Fmoc, which may be removed by treatment with dilute piperidine (20% in DMF); (4-methoxybenzyl)oxycarbonyl and 2-nitrophenylsulphenyl. The Boc and Fmoc groups are particularly preferred. Suitable carboxyl protecting groups that Za may include are, for example, methyl, tert-butyl, benzyl and 4-methoxybenzyl. We particularly prefer benzyl, which may be readily removed by treatment with alcoholic amine or ammonia to give the corresponding amides. Similar groups may be used to protect the amino group in lysine and the carboxyl group in aspartic acid.

When the peptide is prepared using solid phase techniques, for example those in which the carboxyl end of the peptide is attached to a solid phase resin, linkage of the peptide to the resin acts as a carboxyl protecting group. Cleavage of the peptidyl-resin linkage will deprotect the carboxyl terminus of the peptide. Since the peptide end products of this invention are carboxyl terminal amides, the chemical link which connects the peptide chain to the resin must be such that its cleavage with suitable reagents readily provides amides. Due to the lability of the sulphate ester group to strong acids (for example, liquid hydrogen fluoride), the peptidyl-resin linkage may be cleavable with either weaker acids (for example, brief treatment with trifluoroacetic acid, TFA) and/or nucleophiles (for example, ammonia, amines, hydroxide, and alkoxides).

Process (c) may be carried out in an inert solvent, for example DMF, in the presence of a base such as N-methylmorpholine, and at a temperature of, for example, from 0°- 50°C.

Process (d) may be carried out using an activated ester derivative of the acid. A suitable activated ester derivative is the N-hydroxy succinimidyl ester. The reaction may be carried out in the presence of a base such as N-methylmorpholine, under similar conditions to those described for process (c) above.

Among suitable resin derivatives may be mentioned oxymethyl-polystyrene, 4-(oxymethylphenyl)-(CH₂)_n-aminomethyl-polystyrene(n=0-3)and4-(oxymethylphenyl)- oxymethyl-polystyrene. Similarly substituted polyacrylamide resins are equally well suited as the above polystyrene based resins. The term "polystyrene" includes copolymers with minor amounts, usually 1%, of unsaturated monomers such as divinylbenzene. 4-(Oxymethylphenyl)-CH₂CO-aminomethyl-polystyrene [herein referred to as 4-(oxymethylphenyl)-acetamidomethylpolystyrene or OCH₂-Pam-resin] is particularly preferred for the generation of peptide amides. This linkage may readily be cleaved to give the peptides of formula I by reaction with methanolic solutions of ammonia, alkylamines or dialkylamines as required.

Another resin which may be mentioned is a polystyrene resin (P) in which the backbone linkage to the peptide is,

and herein referred to as [[5-[(4-Fmoc-aminomethyl)-3,5- dimethoxyphenoxy]vaIeroyl]norleucyl]-4'-methylbenzhydrylamine divinylbenzene polystyrene or PAL resin. PAL resin is particularly preferred for the generation of peptide amides in which X is not Lys. The linkage between the assembled peptide and this resin may be cleaved readily by reaction with the reagent formed by mixing TFA (trifluoroacetic acid), phenol, thioanisole, water and ethanedithiol in the proportions 8.5:0.5:0.5:0.5:0.2.

Another resin which may be substituted for the PAL resin is a polystyrene resin (P) in which the backbone linkage to the peptide is

, andreferredtoas4-[(2,4-dimethoxyphenyl)(Fmoc-amino)methyl]phenoxydivinylbenzene polystyrene or Rink resin. The linkage may be readily cleaved in the same manner as for PAL resin.

5 The peptides of formulae III, IV and V may be prepared by methods well known to those skilled in the art. For example, they may be prepared by combining individual amino acids on a solid phase resin on a step-by-step basis, or alternatively, by combining groups of amino acids on a solid phase resin to yield the desired peptidyl-resin intermediate. Such additions are accomplished by protecting the amino group of the o amino acid or group of amino acids by converting it to, for example, its tert-butyloxycarbonyl (Boc) or 9-fluorenylmethyl-oxycarbonyl (Fmoc) derivative, and then activating the carboxylic group of such amino acid or group of amino acids by converting it, for example, to its 1-hydroxybenzotriazole (HOBt) or N-hydroxysuccinimide (HOSu) ester derivative. Such a protected-activated intermediate is then allowed to react with s an amino acid resin or peptidyl-resin with a free amino group, thus extending the peptide chain to provide the desired peptidyl-resin.

The C-terminal amino acid of the peptide to be prepared may be attached to the OCHj-Pam-resin in several ways. For example, Boc-protected N-methylphenylalanine, o may be reacted with a suitable 4-(bromomethyl)-phenylacetate ester (for example, phenacyl ester) and processed further to provide Boc-MePhe-(4-oxymethylphenyl)acetic acid which may be coupled to aminomethyl-polystyrene to provide Boc-MePhe- (4-oxymethylphenyl)acetamidomethylpolystyrene (Boc-MePhe-OCH₂-Pam-resin). Alternatively, 4-(bromomethyl)phenylacetic acid may be coupled to s aminomethylpolystyrene to provide 4-(bromomethyl)phenylacetamidomethylpolystyrene (BrCH₂-Pam-resin) which may be reacted with the caesium salt of Boc-MePhe-OH to provide Boc-Phe-OCH₂-Pam-resin.

The C-terminal amino acid may be attached to the PAL resin by removal of the Fmoc 0 protecting group with base, for example, piperidine, in a suitable solvent or mixture of solvents, for example, DMF and toluene, and then coupling the protected activated amino acid in the normal manner for solid phase synthesis. A particularly preferred method of activating the carboxyl group is to form the N-hydroxybenzotriazole (HOBt) ester in the presence of diisopropylcarbodiimide (DIPCDI). Suitable solvent systems, for example, dimethylformamide (DMF) and dichloromethane (DCM) may be used for this preactivation procedure.

Among the suitable activating groups may be mentioned any combination of groups which causes the acid function of the amino acid to become more reactive, such as acid chlorides, mixed and symmetrical anhydrides, reaction product with carbodϋmide (for example, dicyclohexylcarbodiimide, DCC), and active esters (for example, esters derived from HOBt, HOSu, 2- or 4-nitrophenol, and 2,4,5-trichlorophenol). The use of DCC and esters of HOBt and HOSu is particularly preferred from the standpoint of yield, lack of by-products, and consequent ease of purification.

An automatic peptide synthesizer may be used for the solid phase synthesis of the sulphated peptide amides of this invention. The sulphate ester containing peptides of formula I may be desalted and purified by the usual methods. For example, the product may be purified by ion-exchange chromatography with the use of Trisacryl M DEAE, DEAE-cellulose or the like, partition chromatography with the use of Sephadex LH-20, Sephadex G-25 or the like, reverse phase chromatography with the use of Amberlite XAD-2 (or Biorad SM-2), ODS-silica gel or the like, normal phase chromatography with the use of silica gel or the like, or high-performance liquid chromatography (HPLC).

The protocol of coupling onto an aminomethyl-resin or peptidyl-OCH₂-Pam-resin (1 mmole of available nitrogen), deprotection, sulphation, cleavage, and product purification is set forth in Table 1.

Table 1

activated (0°C, 1 hr) activated mixture of protected amino DCC/HOBt acid (or protected coupling dipeptide, 3mmole), HOBt (4.5mmole), and DCC (3mmole) in 1:4 DMF/DCC Go to step 10, 16, 21 or 26 Add protected amino acid In situ 2-15 hr (or protected dipeptide, activated 3mmole) in and HOBt DCC/HOBt (4.5mmole) in 30ml coupling

1:2 DMF/DCM then DCC (3mmole) in 20ml DCM 2-propanol Wash 1 min Go to step 10, 16, 21 or 26 Add active ester or anhydride (3mmole) in DCM, DMF or a mixture thereof Go to step 10, 16, 21 or 26 DCM Treat with 49:1 TFA/ anisole/DCM DCM Treat with 1:19 DIEA7DCM DCM Go to step 10, 16, 21 or 26 DMF Treat with 1:4

piperidine/DMF Fmoc removal 7 min

Wash 1 min

Wash 1 min

Go to step 10, 16, 21 or 26 Methanol Ammonia saturated (-20°C) methanol or 20% methanolic amine (250ml) Methanol Combine and concentrate filtrates from steps 27-28 Chromatograph residue

on column(s) of Amberlite XAD-2 (Rohm and Haas, 2.5 x 60 cm, methanol gradient 0.1M in ammonia), Trisacryl M DEAE (LKB Inc., 2.5 x 47 cm, ammonium bicarbonate gradient), and/or P-40 ODS-3 (Whatman,

4.8 x 50 cm, methanol gradient 0.2% in ammonium acetate). * DIEA is diisopropylethylamine

A general procedure for the synthesis of non-sulphated peptide amides on PAL-resin (lg scale) is set out in Table 2.

1 min

10 min

1-2 hr

Modifications of the protocols in Tables 1 and 2 which may be applicable may readily be determined by experimentation.

Analogous- procedures, wherein the reactions are carried out without the solid phase component (resin), are well known in the art and are well suited to large scale production (see for example US Patent No 3,892,726). The compounds of the invention inhibit feeding activity in mammals, and to bind to cholecystokinin receptors. Distinct CCK receptors in peripheral and brain tissues have been classified as CCK-A and CCK-B receptors respectively. Differentiation between agonist and antagonist interactions at CCK receptors can also be determined by s functional assays. Activation of CCK-A receptors in peripheral tissues plays an important role in the control of pancreatic secretion, gut motility and gall bladder contraction. Thus compounds with agonist activity at CCK-A receptors have utility in the treatment of obesity and motility disorders and compounds with antagonist activity at CCK-A receptors may have utility in gastrointestinal disorders such as irritable bowel 0 syndrome, ulcers, excess pancreatic or gastric secretion, acute pancreatitis and motility disorders. Therefore, compounds intended for use as therapeutic agents in the inhibition of feeding are likely to lack unwanted side-effects if they bind selectively to CCK-A receptors (rather than CCK-B receptors).

s Pharmacological activity of the compounds of the invention can be demonstrated in Tests A-D below.

Test A

Feeding inhibition o Male Sprague-Dawley rats (weighing 300-350g) are individually caged and maintained on a 12 hour light/dark cycle and trained for at least 14 days to feed during a three hour period of the dark cycle but not the 21 hours preceding that three hour period. On the day of the study, rats are dosed intraperitoneally with saline (controls) or test compound (dissolved in saline; usually at a concentration of 0.3 to 30Qμg of test compound per kg 5 of rat weight). Food is introduced 10 minutes after administration of saline or test compound. A test compound is deemed to be active if the test group consumes significantly less food than the saline controls during the feeding period, which ends either 0.5 or three hours after presentation of the food.

0 Test B

CCK-A Binding

Evaluation of a test compound for its ability to bind to CCK-A receptors in rat pancreatic membranes is measured against the binding of Bolton Hunter ^12SI-CCK-8 and ³H-L364718 to rat pancreas according to the procedures of Chang, Lotti, Chan and Kunkel (Molecular Pharmacolgy, 30:212-216, 1986).

Test C s CCK-B Binding

Evaluation of a test compound for its ability to bind to CCK-B receptors in rat cerebral cortex membranes is measured against ¹²⁵I-CCK-8 according to the procedures of Chang and Lotti (Proc, Natl. Acad. Sci. Vol. 83, 4923-4926).

Test D

Functional Assay For CCK-A Agonist/Antagonist Activity

The evaluation of a test compound for its ability to inhibit or stimulate amylase release by rat pancreatic tissue fragments (acinar cells) is measured according to the procedures of Lin et al (J Pharm & Exper Therapeutics, 1986, 729-734) and Jung (Clinica Chema Acta, 1980, 100, 7-11).

Therefore, the invention also provides the use of a compound of the invention as a pharmaceutical.

According to a further aspect of the invention there is provided the use of a compound of the invention in the manufacture of a medicament for the treatment of obesity.

According to the invention there is also provided a method of treatment of obesity which comprises administering a therapeutically effective amount of a compound of the invention to a patient in need of such treatment; and also a method of improving the bodily appearance of a mammal which comprises administering to that mammal a compound of the invention until a cosmetically beneficial loss of body weight has occurred. The mammals of greatest interest are human beings.

According to a further aspect of the invention there is also provided a pharmaceutical formulation comprising (preferably less than 80%, and more preferably less than 50% by weight of) a compound of the invention in combination with a pharmaceutically acceptable adjuvant, diluent or carrier. The compounds of the invention may be administered by a variety of routes, for example, orally, intraperitoneally, intravenously, intramuscularly, subcutaneously or intranasally. The dosage of the compounds of the invention will depend on several factors, including the requirements of the recipient, but will typically be in the range s 0.3μg to 3.0mg per kg of body weight per day, either in a single dose or divided among two to four doses.

Examples of suitable adjuvants, diluents or carriers are: for tablets and dragees; lactose, starch, talc or stearic acid; o for capsules; tartaric acid or lactose; for injectable solutions; water, alcohols, glycerin or vegetable oils.

The compositions may also contain suitable preserving, stabilising and wetting agents, solubilisers (eg a water-soluble cellulose polymer such as hydroxypropyl methylcellulose, s or a water-soluble glycol such as propylene glycol), sweetening and colouring agents and flavourings. The compositions may, if desired, be formulated in sustained release form.

The compounds of the invention have the advantage that they are more efficacious, more potent, longer acting, more stable (particularly to enzymatic degradation), more o selective, less toxic, give rise to fewer side effects, are more readily absorbed, are quicker acting, or have other advantageous pharmacological effects, in comparison with the compounds of the prior art.

The invention is illustrated by the following examples, in which an automatic peptide 5 synthesizer was used for solid phase synthesis.

Example 1

Boc-MePhe-f4-oxymethylphenyπacetic acid

To a solution of Boc-MePhe-OH (27.93g) and 4-(bromomethyl)phenylacetic acid 0 phenacyl ester (33.32g) in acetonitrile (11) was added potassium fluoride dihydrate (18.28g). The suspension was stirred overnight, filtered and the filtrate evaporated to dryness. The residue, Boc-MePhe-(4-oxymethylphenyl)acetic acid phenacyl ester, was dissolved in 85% acetic acid (1.21), treated with zinc dust (128g), and stirred for 2-4 hours. Concentration of the filtered reaction mixture to about 400ml and dilution with 3.2ml of water gave an oil which was dissolved in ethyl acetate and treated with dicyclohexylamine (DCHA) to give 41.3 lg of the DCHA salt of the title compound, mp 120-122°C.

Example 2

H-MePhe-OCH -Pam-resin

Boc-MePhe-(4-oxymethylphenyl)acetic acid (the product of Example 1, 1.82g, 3mmole of its DCHA salt) and HOBt (6.9g, 4.5mmole) in 40ml of 1:3 DMF/DCM (dimethylformamide/dichloromethane) followed by DCC (1,3-dicyclohexylcarbodiimide, 0.62g, 3mmole) in 20ml of DCM were added to aminomethylpolystyrene resin (1.34g, lmmole available nitrogen) to give a suspension which was shaken for 2 to 15 hours. Boc-MePhe-OCH₂-Pam-resin was isolated by filtration, washed with 2-propanol and DCM, and treated according to Table 1 (steps 10-14) to give the title compound as the free base.

Example 3

H-Phe-OCH-,-Pam-resin

Boc-Phe-(4-oxymethylphenyl)acetic acid (prepared by the method of Example 1, 0.83g, 2mmole), l-hydroxybenzotriazole (HOBt, 0.46g, 3mmole) and DCC (0.41g, 2mmole) were dissolved in 50ml of 4:1 DCM/DMF and stirred at 0°C for 1 hour.

Aminomethylpolystyrene resin (1.34g, lmmole available nitrogen) was suspended in the filtered reaction mixture (precipitated DCU removed) and shaken for 2-15 hours. The product, Boc-Phe-OCH₂-Pam-resin, was isolated by filtration and treated according to Table 1 (steps 10-14) to give the title compound.

Example 4

Fmoc-Met-AsprOtBuVOH

Fmoc-Met-OSu was prepared in situ by the reaction of Fmoc-Met-OH (14.87g), HOSu (5.52g) and DCC (8.26g) in THF (tetrahydrofuran, 200ml) at 0°C for 3.5 hours. Precipitated dicyclohexylurea (DCU) was removed by filtration and the THF filtrate was added to a cold solution of H-Asρ(OtBu)-OH in 220ml of 10:1 water/THF to which had been added 40ml of IN sodium hydroxide. After stirring the reaction mixture at room temperature overnight, solid citric acid (20g) was added along with ethyl acetate (600ml). The ethyl acetate layer was separated, washed with 10% citric acid and brine, then dried (MgS0₄). Evaporation of the ethyl acetate solution gave a residue which was dissolved in ethyl acetate (200ml) and treated with DCHA (7.84ml) to precipitate 17.93g s of the DCHA salt of the title compound, mp 159-162°C.

Example 5

HpafSO,HVAhx-Glv-Trp-Ahx-Asp-Phe-NH, (SEQ ID NO 1)

H-Phe-OCH₂-Pam-resin (the product of Example 3) was sequentially coupled with o Fmoc-Asρ(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH according to Table 1 (coupling steps 5-7 followed by Fmoc removal steps 16-20) to provide H-Ahx-Gly-Trp-Ahx-Asp(OtBu)-Phe-OCH₂-Pam-resin which was coupled with Hpa-OSu according to Table 1 (coupling steps 8-9) to give Hpa-Ahx-Gly-Trp-Ahx- Asp(OtBu)-Phe-OCH₂-Pam-resin which was deprotected, sulphated and cleaved from s the resin according to Table 1 (steps 10-15, steps 21-25 and then steps 26-29 with ammonia) to give the title compound which was chromatographically purified on SM-2 and ODS-3 columns sequentially according to Table 2 (step 18). Amino acid analysis following acid decomposition gave Asp 1.03(1), Gly 1.05(1), Ahx 1.94(2), Phe 0.99 (1), Tip 0.74 (1), NH₃ 2.16. MS (FAB): m/e 961 (M-H)\ 0

Example 6

Hpa-Met-Glv-Trp-Met-DAsp-Phe-NH,

PAL-resin was deprotected and sequentially coupled according to Table 2 with Fmoc- Phe-OH, Fmoc-DAsp(OtBu)-OH, Fmoc-Met-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc- Met-OH and Hpa-OSu to provide the title compound. Amino acid analysis following acid decomposition gave Asp 1.04(1), Gly 1.07(1), Met 1.79(2), Phe 1.10(1), Trp 0.71(1.0), NH₃ 1.40. MS (FAB): m/e 919 (M+H)⁺.

Example 7 Hpa-Ahx-Glv-Trp-Ahx-Asp-Phe-NH, fSEO ID NO 2^

PAL-resin was deprotected and sequentially coupled according to Table 2 with Fmoc- Phe-OH, Fmoc-Asρ(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc- Ahx-OH and Hpa-OSu to provide the title compound. Amino acid analysis following acid decomposition gave Asp 1.00(1), Gly 1.08(1.0), Ahx 1.85(2), Phe 1.10(1), Trp 0.68(1), NH₃ 1.00. MS (FAB): m/e 883 (M+H)⁺.

Example 8 s Hpa-Ahx-GIv-Trp-Ahx-MeAsp-Phe-NH-, fSEQ ID NO 3)

PAL-resin was deprotected and sequentially coupled according to Table 2 with Fmoc- Phe-OH, Fmoc-MeAsρ(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, to give the title compound. Amino acid analysis following acid decomposition gave Gly 0.89(1), MeAsp 1.04(1), Ahx 1.99(2), Phe 1.09(1), Trp 0.71(1), NH₃ 0.91. MS (FAB): m e 897 (M+H)⁺.

Example 9

Hpa-Ile-Glv-Trp-IIe-DAsp-MePhe-NH_?

PAL-resin was deprotected and sequentially coupled according to Table 2 with Fmoc- MePhe-OH, Fmoc-DAsρ(OtBu)-OH, Fmoc-IIe-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-He-OH and Hpa-OSu, to give the title compound. Amino acid analysis following acid decomposition gave Asp 1.00(1), Gly 1.14(1), He 1.91(2), MePhe 0.96(1), Trp 0.64(1), NH₃ 1.44. MS (FAB): m/e 897 (M+H)⁺.

Example 10

HparSO,m-Met-GIv-Trρ-Met-DAsρ-Phe-NH,

Hpa-Met-Gly-Trp-Met-DAsp-Phe-NH₂ (the product of Example 6, 114mg) was dissolved in pyridine (1.4ml) and sulphur trioxide pyridine complex (130mg) was added. The reaction was stirred for 2 hours then an additional 80mg of sulphur trioxide pyridine complex was added. After 4 hours the reaction was diluted with 5% NH₄OH (20ml) and concentrated to dryness. The crude residue was purified by chromatography on SM-2, ODS-3, SM-2 sequentially according to Table 2, step 18. The resulting product was freeze dried from 0.1M NH₃ to give the title compound (89mg). Amino acid analysis following acid decomposition gave Asp 1.03(1), Gly 1.11(1), Met 1.83(2), Phe 1.04(1), Trp 0.59(1), NH₃ 2.2. MS (FAB): m e 997 (M-H)\

Example 11

HpafSO,m-Ahx-GIv-Trp-Ahx-MeAsp-Phe-NH, (SEQ ID NO 4) Hpa-Ahx-Gly-Trp-Ahx-MeAsp-Phe-NH₂ (the product of Example 8, 55mg) was sulphated essentially according to the method of Example 10 to give purified title compound (15mg). Amino acid analysis following acid decomposition gave MeAsp 1.07(1), Gly 1.04(1), Ahx 1.90 (2), Phe 0.98 (1), Trp 0.61 (1), NH₃ 0.79. MS (FAB): m/e s 975 (M-H)\

Example 12

HpafSO,HVIle-Glv-Trp-Ile-DAsp-MePhe-NH,

Hpa-Ile-Gly-Trp-Ile-DAsp-MePhe-NH₂ (the product of Example 9, 58mg) was sulphated o essentially according to the method of Example 10 to give purified title compound

(16mg). Amino acid analysis following acid decomposition gave Asp 1.08(1), Gly

1.08(1), He 1.97(2), MePhe 0.87(1), Trp 0.75(1) NH₃ 1.39. MS (FAB): m/e 975 (M-H)\

Example 13 s Hpa-Met-Glv-Trp-Met-Asp-MePhe-NH₇ rSEQ ID NO 5

The title compound was prepared following the method of Table 2, sequentially coupling Fmoc-MePhe-OH, Fmoc-Asp(OtBu)-OH, Fmoc-Met-OH, Fmoc-Trp-OH, Fmoc-Gly- OH, Fmoc-Met-OH and Hpa-OSu. Amino acid analysis following acid decomposition gave Asp 1.06 (1). Gly 1.04 (1), MePhe 1.00 (1), Met 1.90 (2), Trp 0.84 (1), NH₃ 0.51. 0 MS (FAB): m/e 931 (M-H)-.

Example 14

Hpa-Ahx-Glv-Trp-Ahx-DAsp-MePhe-NH_?

PAL resin was sequentially coupled according to Table 2 with Fmoc-MePhe-OH, Fmoc- DAsρ(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, to give the title compound. Amino acid analysis following acid decomposition gave Asp 1.03(1), Gly 1.04(1), Ahx 1.95(2), MePhe 0.99(1), Trp 0.77(1), NH₃ 0.94. MS (FAB): m/e 895 (M-H)^".

Example 15

Hpa-Ahx-GIv-Trp-Ile-DAsp-Phe-NH,

PAL resin was sequentially coupled according to Table 2 with Fmoc-Phe-OH, Fmoc-

DAsp(OtBu)-OH, Fmoc-Ile-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, to give the title compound. Amino acid analysis following acid decomposition gave Asp 1.03(1), Gly 1.04(1), Ahx 0.96(1), He 0.98(1), Phe 1.00(1), Trp 0.67(1), NH₃ 0.99. MS (FAB): m e 881 (M-H)\

s Example 16

Hpa-Ahx-Glv-Trp-He-MeAsp-Phe-NH₇ (SEQ ID NO 6)

PAL resin was sequentially coupled according to Table 2 with Fmoc-Phe-OH, Fmoc- MeAsp(OtBu)-OH, Fmoc-He-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, to give the title compound. Amino acid analysis following acid decomposition gave MeAsp 1.19(1), Gly 1.00(1), Ahx 1.02(1), Phe 0.91(1), He 0.89(1), Trp 0.65(1), NH₃ 0.60. MS (FAB): m/e 895 (M-H)\

Example 17

Hpa-Ahx-Glv-Trp-IIe-Asp-MePhe-NH, (SEQ ID NO 7) PAL resin was sequentially coupled according to Table 2 with Fmoc-MePhe-OH, Fmoc- Asp(OtBu)-OH, Fmoc-He-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa- OSu, to give the title compound. Amino acid analysis following acid decomposition gave Asp 1.10(1), Gly 1.09(1), Ahx 1.06(1), He 1.05(1), MePhe 0.71(1), Trp 0.76(1), NH₃ 0.80. MS (FAB): m e 895 (M-H)\

Example 18

HpafSO,HVAhx-Glv-T -Ile-DAsp-Phe-NH₇

Hpa-Ahx-GIy-Trp-He-DAsp-Phe-NH₂ (the product of Example 15, 41mg) prepared according to Table 2 was sulphated essentially according to the method of Example 10 to give purified title compound (22mg). Amino acid analysis following acid decomposition gave Asp 1.07(1), Gly 1.04(1), He 0.97(1), Phe 0.80(1), Trp 0.46(1) NH₃ 1.88. MS (FAB): m e 961 (M-H)\

Example 19 Hpa-Met-Glv-T_φ-Met-AspfOBnVMePhe-NH₇ fSEQ ID NO 8)

By following essentially the procedures of Table 2 and sequentially coupling with Fmoc- MePhe-OH, Fmoc-Asp(OBn)-OH, Fmoc-Met-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Met-OH and Hpa-OSu, the title compound was prepared. MS (FAB): m/e 1023 (M+H)⁺.

Example 20 s HpafSO,HVMet-Glv-Trp-Met-Asp(OBnVMePhe-NH, TSEO ID NO 9)

Hpa-Met-Gly-Trp-Met-Asp(OBn)-MePhe-NH₂ (the product of Example 19) was sulphated essentially according to the procedures of Example 10 to give the purified title compound. Amino acid analysis following acid decomposition gave Asp 1.07(1), Gly 0.99(1), Met 1.91 (2), MePhe 1.02(1), Trp 0.47(1). MS (FAB): m/e 1101 (M-H)\ 0

Example 21

Hpa-Ahx-Glv-Trp-He-DAsp-MePhe-NH₇

By following essentially the procedure of Table 2 and sequentially coupling Fmoc- MePhe-OH, Fmoc-DAsp(OtBu)-OH, Fmoc-He-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, s Fmoc-Ahx-OH and Hpa-OSu, the title compound was prepared. Amino Acid analysis following acid decomposition gave Asp 0.96 (1), Gly 1.04 (1), He 0.96 (1), MePhe 1.07 (1), Ahx 0.98 (1), Trp 0.61 (1), NH₃ 0.89. MS (FAB): m/e 895 (M-H)\

Example 22 0 HparSO,HVAhx-Glv-Trp-Ile-DAsp-MePhe-NH

Hpa-Ahx-Gly-Trp-Ile-DAsp-MePhe-NH₂ (the product of Example 21) was sulphated essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave Asp 0.98 (1), Gly 1.07 (1), He 0.95 (1), MePhe 1.41 (1), Ahx 0.81 (1). MS (FAB): m/e 975 (M-H)\ m/e 895 (M- 5 S0₃H)\

Example 23

HpafSO,HVA_hx-Glv-Trp-Ile-Asp-MePhe-NH, (SEQ ID NO 10) Hpa-Ahx-Gly-Trp-Ile-Asp-MePhe-NH₂ (the product of Example 17) was sulphated essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave Asp 0.98 (1), Gly 1.08 (1), He 0.96 (1), MePhe 1.55 (1), Ahx 0.84 (1). MS (FAB): m/e 975 (M-H)\ m e 895 (M- S0₃H)\ Example 24

HpafSO,H>Ahx-Glv-T -Ahx-DAsp-MePhe-NH,

Hpa-Ahx-Gly-Trp-Ahx-DAsp-MePhe-NH₂ (the product of Example 14) was sulphated essentially according to the procedures of Example 10 to give the title compound, s Amino Acid analysis following acid decomposition gave Asp 1.00 (1), Gly 0.98 (1), MePhe 1.10 (1), Ahx 1.93 (2), Trp 0.96 (1), NH₃ 0.30. MS (FAB): m/e 975 (M-H)\

Example 25 Hpa-Ile-Glv-Trρ-He-DAsp-Phe-NH₇ io By following essentially the procedure of Table 2 and sequentially coupling Fmoc-Phe- OH, Fmoc-DAsp(OtBu)-OH, Fmoc-He-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-He- OH and Hpa-OSu, the title compound was prepared. Amino Acid analysis following acid decomposition gave Asp 1.02 (1), Gly 1.03 (1), Phe 1.01 (1), He 1.94 (2), Trp 0.72 (1), NH₃ 0.85. MS (FAB): m/e 881 (M-H)^'.

Example 26

HpafSO,HVIle-Glv-Trp-Ile-DAsp-Phe-NH,

Hpa-He-Gly-Trp-He-DAsp-Phe-NH₂ (the product of Example 25) was sulphated essentially according to the procedures of Example 10 to give the title compound. 0 Amino Acid analysis following acid decomposition gave Asp 0.92 (1), Gly 1.03 (1), Phe 0.99 (1), He 1.93 (2). MS (FAB): m/e 961 (M-H)^', m/e 881 (M«S0₃H)\

Example 27

Hpa-Ahx-Glv-Trp-Phe-DAsp-MePhe-NH₇ s By following essentially the procedure of Table 2 and sequentially coupling Fmoc- MePhe-OH, Fmoc-DAsp(OtBu)-OH, Fmoc-Phe-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, the title compound was prepared. Amino Acid analysis following acid decomposition gave Asp 1.01 (1), Gly 0.99 (1), MePhe 1.06 (1), Ahx 1.02 (1), Trp 1.06 (1), Phe 0.94 (1), NH₃ 0.82. MS (FAB): m/e 931 (M-H)\

Example 28 HparSO,HVAhx-Glv-Trp-Phe-DAsp-MePhe-NH₇ Hpa-Ahx-Gly-Trp-Phe-DAsp-MePhe-NH₂ (the product of Example 27) was sulphated essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave Asp 0.98 (1), Gly 1.06 (1), MePhe 0.97 (1), Ahx 0.95 (1), Trp 0.61 (1), Phe 1.04 (1), NH₃ 1.10. MS (FAB): m/e s 1009 (M-H)\ m/e 929 (M-S0₃H)\

Example 29

HpafSO,HVAhx-Glv-Trp-Ahx-DAsp-Phe-NH,

Hpa-Ahx-Gly-Trp-Ahx-DAsp-Phe-NH₂ was prepared by the method of Table 2, and o sulphated essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave Asp 1.02 (1), Gly 1.05 (1), Phe 1.02 (1), Ahx 1.92 (2), Trp 0.81 (1), NH₃ 1.48. MS (FAB): m/e 961 (M-H)^" , 881 (M-S0₃H)\

s Example 30

HparSO,HVAhx-Glv-Trp-Ile-MeAsp-MePhe-NH₇ (SEQ ID NO 11) Hpa-Ahx-Gly-Trp-Ile-MeAsp-MePhe-NH₂ (SEQ ID NO 12) was prepared by the method of Table 2, and sulphated essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave 0 MeAsp 0.92 (1), Gly 1.00 (1), MePhe 1.29 (1), Ahx 0.77 (1), He 1.02 (1). MS (FAB): m/e 989 (M-H)^", 909 (M-S0₃H)\

Example 31

HpafSO,HVIle-Glv-Trp-Ile-MeAsp-Phe-NH., (SEQ ID NO 13) 5 Hpa-Ile-Gly-Trp-Ile-MeAsρ-Phe-NH₂ (SEQ ID NO 14) was prepared by the method of Table 2, and sulphated essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave MeAsp 1.11 (1), Gly 1.00 (1), Phe 1.06 (1), He 1.83 (2), Trp 0.73 (1), NH₃ 1.48. MS (FAB): m/e 975 (M-H)^", 897 (M-S0₃H)\ 0

Example 32 Hpa-Ahx-Glv-Trp-Ahx-MeDAsp-Phe-NH, By following essentially the procedure of Table 2 and sequentially coupling Fmoc-Phe- OH, Fmoc-MeDAsp(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc- Ahx-OH and Hpa-OSu, the title compound was prepared. Amino Acid analysis following acid decomposition gave MeAsp 0.78 (1), Gly 1.10 (1), Phe 1.05 (1), Ahx 2.07 s (2), Trp 0.76 (1), NH₃ 0.71. MS (FAB): m/e 895 (M-H)^'.

Example 33

HpafSO,HVAhx-GIv-Tι?-A_hx-MeDAsp-Phe-NH,

Hpa-Ahx-GIy-Trp-Ahx-MeDAsp-Phe-NH₂ (the product of Example 32) was sulphated ιo essentially according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave MeAsp 1.00 (1), Gly 1.02 (1), Phe 1.06 (1), Ahx 1.91 (2), Trp 0.86 (1), NH₃ 1.48. MS (FAB): m/e 975 (M-H)^', m e 896 (M-S0₃H)\

is Example 34

Hpa-Ahx-Glv-Trp-Ahx-MeAsp-MePhe-NH_? (SEQ ID NO 15) By following essentially the procedure of Table 2 and sequentially coupling Fmoc- MePhe-OH, Fmoc-MeAsp(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, the title compound was prepared. Amino Acid analysis 0 following acid decomposition gave MeAsp 1.01 (1), Gly 1.05 (1), MePhe 0.91 (1), Ahx 2.02 (2), Trp 0.84 (1), NH₃ 0.82. MS (FAB): m/e 909 (M-H)^".

Example 35

Hpa-Ahx-GIv-Trp-LvsrTacVAsp-MePhe-NH_? (SEQ ID NO 16) s Following the procedure of Table 2, Fmoc-MePhe-OH, Fmoc-Asp(OtBu)-OH, Fmoc- Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Lys(Boc)-OH and Hpa-OSu were sequentially coupled to the Rink amide resin. Following removal of the peptide from the resin using standard procedures the 2-methylphenylacetamide group was added to the ε-amino of Lys using o-tolylisocyanate. Amino Acid analysis following acid decomposition gave Asp 1.01 (1), Gly 1.03 (1), MePhe 0.98 (1), Lys 0.94 (1), Ahx 1.04 (1), Trp 0.96 (1). MS (FAB): m/e 1046 (M-H)⁺.

Example 36 HpafSO_^HVAhx-GIv-Trp-LvsfTacVAsp-MePhe-NH, (SEQ ID NO 17) Hpa-Ahx-Gly-Trp-Lys(Tac)-Asp-MePhe-NH₂ (the product of Example 35) was sulphated according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition gave Asp 1.01 (1), Gly 1.04 (1), MePhe 0.92 (1), s Lys 0.93 (1), Ahx 1.10 (1), Trp 0.84 (1). MS (FAB): m/e 1123 (M-H)^".

Example 37

Hpa-Ahx-Glv-Trp-Ahx-Asp-MePhe-NH, (SEQ ID NO 18)

Following the procedure of Table 2 and sequentially coupling Fmoc-MePhe-OH, Fmoc- o Asp(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Gly-OH, Fmoc-Ahx-OH and Hpa-OSu, to the resin, the title compound was prepared. Amino Acid analysis following acid decomposition gave Asp 1.00 (1), Gly 1.02 (1), MePhe 1.05 (1), Ahx 2.1 (2), Trp 0.53 (1), NH₃ 0.69. MS (FAB): m/e 897 (M+H)⁺.

s Example 38

Hpa-Ahx-Sar-Trp-Ahx-Asp-MePhe-NH_? (SEQ ID NO 19)

Following the procedure of Table 2 and sequentially coupling Fmoc-MePhe-OH, Fmoc- Asp(OtBu)-OH, Fmoc-Ahx-OH, Fmoc-Trp-OH, Fmoc-Sar-OH, Fmoc-Ahx-OH and Hpa-OSu, to the resin, the title compound was prepared. Amino Acid analysis following 0 acid decomposition gave Asp 0.93 (1), Sar 1.12 (1), MePhe 0.95 (1), Ahx 1.99 (2), Trp 1.06 (1), HN₃ 0.88. MS (FAB): m/e 909 (M-H)^".

Example 39

HpafSO,HVAhx-Sar-Trp-Ahx-Asp-MePhe-NH, (SEQ ID NO 20) s Hpa-Ahx-Sar-Trp-Ahx-Asp-MePhe-NH₂ (the product of Example 38) was sulphated according to the procedures of Example 10 to give the title compound. Amino Acid analysis following acid decomposition Asp 1.04 (1), Sar 0.87 (1), MePhe 0.86 (1), Ahx 2.23 (2), Trp 0.89 (1), NH₃ 1.31, MS(FAB) m/e 989 (M-H)\

0 Example 40

The compound of Example 32 was tested in Test B above, and found to bind to CCK-A receptors with a binding constant (K_j) of 0.03nM. Sequence Listing (Total of 20 sequences) (1) INFORMATION FOR SEQ ID NO 1: s (i.) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear io (ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: isc-feature

(B) LOCATION: 1 s (D) OTHER INFORMATION: Xaa is N-[2-(O-sulpho-4- oxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature 0 (B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature S (B) LOCATION: 6

(D) OTHER INFORMATION: Xaa is phenylalanine amide

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 1 Xaa Gly Trp Leu Asp Xaa 1 5

(2) INFORMATION FOR SEQ ID NO 2: (i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1 (D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxypheny1)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 4.

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 6

(D) OTHER INFORMATION: Xaa is phenylalanine amide (Xi) SEQUENCE DESCRIPTION: SEQ ID NO 2

Xaa Gly Trp Leu Asp Xaa

1 5

(3) INFORMATION FOR SEQ ID NO 3:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues (B) TYPE: amino acid

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-Nle

( ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 5

(D) OTHER INFORMATION: Xaa is N-methyl aspartic acid

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHER INFORMATION: Xaa is phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 3

Xaa Gly Trp Leu Xaa Xaa 1 5

(4) INFORMATION FOR SEQ ID NO 4:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues (B) TYPE: amino acid

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(0-sulpho-4- oxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 5 (D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 6 (D) OTHER INFORMATION: Xaa is phenylalanine amide

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 4

Xaa Gly Trp Leu Xaa Xaa 1 5

(5) INFORMATION FOR SEQ ID NO 5:

(i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc- eature (B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[4- hydroxyphenyl)ethanoyl]-Met

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide (xi) SEQUENCE DESCRIPTION: SEQ ID NO 5

Xaa Gly Trp Met Asp Xaa 1 5 (6) INFORMATION FOR SEQ ID NO 6:

(i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 1 (D) OTHER INFORMATION: Xaa is N-[4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 5

(D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 6

(D) OTHER INFORMATION: Xaa is phenylalanine amide

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 6 Xaa Gly Trp lie Xaa Xaa 1 5

(7) INFORMATION FOR SEQ ID NO 7: (i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1 (D) OTHER INFORMATION: Xaa is N-[4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 7

Xaa Gly Trp lie Asp Xaa 1 5

(8) INFORMATION FOR SEQ ID NO 8:

(i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxypheny1)ethanoyl]-Met (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 5

(D) OTHER INFORMATION: Xaa is Asp β-benzyl ester

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: XaaisN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 8

Xaa Gly Trp Met Xaa Xaa 1 5

(9) INFORMATION FOR SEQ ID NO 9:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(0-sulpho-4- oxypheny1)ethanoyl]-Met

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 5 (D) OTHER INFORMATION: Xaa is Asp β-benzyl ester

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6 (D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 9 Xaa Gly Trp Met Xaa Xaa 1 5

(10) INFORMATION FOR SEQ ID NO 10: (i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[0-sulpho-4- oxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 10

Xaa Gly Trp lie Asp Xaa 1 5

(11) INFORMATION FOR SEQ ID NO 11:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(0-sulpho-4- oxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 5 (D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6 (D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 11 Xaa Gly Trp lie Xaa Xaa 1 5

(12) INFORMATION FOR SEQ ID NO 12: (i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 5

(D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 12

Xaa Gly Trp lie Xaa Xaa 1 5

(13) INFORMATION FOR SEQ ID NO 13:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(0-sulpho-4- oxyphenyl)ethanoyl]-lie

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 5 (D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6 (D) OTHER INFORMATION: Xaa is phenylalanine amide

( i) SEQUENCE DESCRIPTION: SEQ ID NO 13

Xaa Gly Trp He Xaa Xaa 1 5

(14) INFORMATION FOR SEQ ID NO 14:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-He

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 5

(D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 6 (D) OTHER INFORMATION: Xaa is phenylalanine amide

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 14

Xaa Gly Trp He Xaa Xaa 1 5

(15) INFORMATION FOR SEQ ID NO 15:

(i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature (B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 5 (D) OTHER INFORMATION: Xaa is N-methyl-Asp

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide (xi) SEQUENCE DESCRIPTION: SEQ ID NO 15 Xaa Gly Trp Leu Xaa Xaa 1 5

(16) INFORMATION FOR SEQ ID NO 16:

5

(i) SEQUENCE CHARACTERISTICS

(A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

10

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature s (B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE: 0 (A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Xaa is ε-N-[(2- methylphenyl)aminoσarbonyl]-Lys s (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide 0

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 16

Xaa Gly Trp Xaa Asp Xaa 1 5

(17) INFORMATION FOR SEQ ID NO 17:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues (B) TYPE: amino acid

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(0-sulpho-4- oxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Xaa is ε-N-[(2- methylpheny1)aminocarbony1]-Lys

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 17

Xaa Gly Trp Xaa Asp Xaa

1 5

(18) INFORMATION FOR SEQ ID NO 18;

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues (B) TYPE: amino acid

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 18

Xaa Gly Trp Leu Asp Xaa 1 5

(19) INFORMATION FOR SEQ ID NO 19:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(4- hydroxyphenyl)ethanoyl]-Nle

(ix) FEATURE: (A) NAME/KEY: misc-feature

(B) LOCATION: 2

(D) OTHER INFORMATION: Gly is sarcosine s (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle io (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: Xaa isN-methyl-phenylalanine amide is

(Xi) SEQUENCE DESCRIPTION: SEQ ID NO 19

Xaa Gly Trp Leu Asp Xaa 1 5 0

(20) INFORMATION FOR SEQ ID NO 20:

(i) SEQUENCE CHARACTERISTICS (A) LENGTH: 6 residues s (B) TYPE: amino acid

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: peptide o (ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 1

(D) OTHER INFORMATION: Xaa is N-[2-(0-sulpho-4- oxyphenyl)ethanoyl]-Nle 5

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 2

(D) OTHER INFORMATION: Gly is sarcosine

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 4

(D) OTHER INFORMATION: Leu is Nle

(ix) FEATURE:

(A) NAME/KEY: misc-feature

(B) LOCATION: 6

(D) OTHERINFORMATION: XaaisN-methyl-phenylalanine amide

(xi) SEQUENCE DESCRIPTION: SEQ ID NO 20

Xaa Gly Trp Leu Asp Xaa 1 5

Claims

Claims:

1. A compound of formula I:

wherein R¹ is OH or OS0₃H;

M is Met, Ahx or He;

G is Gly or Sar;

X is Met, Ahx, He, Phe or Lys(R²);

J is Asp, Asp(OBn), DAsp, MeAsp, or MeDAsp; L is Phe or MePhe;

R² is a group of formula II,

wherein E is NH, CH=CH or CH₂CH₂; and R³, R⁴, R⁵, R⁶ and R⁷ are independently H, OH, halogen, alkyl C,^ or OS0₃H; provided that when R¹ is OS0₃H, G is Gly and: (a) J is Asp, L is MePhe and M is Ahx, then X is not Ahx;

(b) J is Asp, L is MePhe and M is He, then X is not He;

(c) J is Asp, L is MePhe and M is He, then X is not Ahx;

(d) J is Asp, L is Phe and M is Met, then X is not Met;

(e) J is Asp, L is MePhe and M is Met, then X is not Met;

(f) J is DAsp, L is MePhe and M is Met, then X is not Met; or a pharmaceutically acceptable derivative thereof.

2. A compound as claimed in claim 1, wherein M is Ahx or He.

3. A compound as claimed in claim 1 or claim 2, wherein X is Ahx, He or Lys(R²).

4. A compound as claimed in any one of the preceding claims, wherein J is Asp, DAsp, MeAsp or MeDAsp.

5. A compound as claimed in any one of the preceding claims, wherein R^l is OS0₃H.

6. A compound as claimed in claim 1, which is: s Hpa(S0₃H)-Ahx-Gly-Trp-Ahx-Asp-Phe-NH₂ (SEQ ID NO 1); Hpa-Met-Gly-Trp-Met-DAsp-Phe-NH₂; Hpa-Ahx-GIy-Trp-Ahx-Asp-Phe-NH₂ (SEQ ID NO 2); Hpa-Ahx-Gly-Trp-Ahx-MeAsp-Phe-NH₂ (SEQ ID NO 3); Hpa-He-Gly-Trp-He-DAsp-MePhe-NH₂; Hpa(S0₃H)-Met-Gly-Trp-Met-DAsp-Phe-NH₂;

Hpa(S0₃H)-Ahx-Gly-Trp-Ahx-MeAsp-Phe-NH₂ (SEQ ID NO 4); Hpa(S0₃H)-He-Gly-Trp-He-DAsp-MePhe-NH₂; Hpa-Met-Gly-Trp-Met-Asp-MePhe-NH₂ (SEQ ID NO 5); Hρa-Ahx-Gly-Trp-Ahx-DAsρ-MePhe-NH₂; Hpa-Ahx-Gly-Trp-He-DAsp-Phe-NH₂;

Hpa-Ahx-Gly-Trp-He-MeAsp-Phe-NH₂ (SEQ ID NO 6); Hpa-Ahx-Gly-Trp-He-Asp-MePhe-NH₂ (SEQ ID NO 7); Hpa(S0₃H)-Ahx-GIy-Trp-He-DAsp-Phe-NH₂; Hpa-Met-Gly-Trp-Met-Asp(OBn)-MePhe-NH₂ (SEQ ID NO 8); Hpa(S0₃H)-Met-Gly-Trp-Met-Asp(OBn)-MePhe-NH₂ (SEQ ID NO 9); Hρa-Ahx-Gly-Trp-Ile-DAsp-MePhe-NH₂; Hpa(S0₃H)-Ahx-Gly-Trp-He-DAsp-MePhe-NH₂; Hpa(S0₃H)-Ahx-Gly-Trp-He-Asp-MePhe-NH₂ (SEQ ID NO 10); Hpa(S0₃H)-Ahx-Gly-Trp-Ahx-DAsp-MePhe-NH₂; Hpa-He-GIy-Trp-He-DAsp-Phe-NH

Hρa(S0₃H)-He-Gly-Trp-He-DAsp-Phe-NH₂; Hpa-Ahx-Gly-Trp-Phe-DAsp-MePhe-NH^ Hpa(S0₃H)-Ahx-Gly-Trp-Phe-DAsp-MePhe-NH₂; Hpa(S0₃H)-Ahx-Gly-Trp-Ahx-DAsp-Phe-NH₂; Hpa-Ahx-Gly-Trp-Ahx-DAsp-Phe-NH^

Hpa(S0₃H)-Ahx-Gly-Trp-Ile-MeAsp-MePhe-NH₂ (SEQ ID NO 11); Hpa-Ahx-Gly-Trp-He-MeAsp-MePhe-NH₂ (SEQ ID NO 12); Hpa(S0₃H)-He-Gly-Trp-Ile-MeAsp-Phe-NH₂ (SEQ ID NO 13); Hpa-Ile-Gly-Trp-Ile-MeAsp-Phe-NH₂ (SEQ ID NO 14);

Hpa-Ahx-Gly-Trp-Ahx-MeDAsp-Phe-NH₂;

Hpa(S0₃H)-Ahx-Gly-Trp-Ahx-MeDAsp-Phe-NH₂;

Hpa-Ahx-Gly-Trp-Ahx-MeAsp-MePhe-NH₂ (SEQ ID NO 15); s Hpa-Ahx-Gly-Trp-Lys(Tac)-Asp-MePhe-NH₂ (SEQ ID NO 16);

Hpa(S0₃H)-Ahx-Gly-Trp-Lys(Tac)-Asp-MePhe-NH₂ (SEQ ID NO 17);

Hpa-Ahx-Gly-Trp-Ahx-Asp-MePhe-NH₂ (SEQ ID NO 18);

Hpa-Ahx-Sar-Trp-Ahx-Asp-MePhe-NH₂ (SEQ ID NO 19);

Hpa(S0₃H)-Ahx-Sar-Trp-Ahx-Asp-MePhe-NH₂ (SEQ ID NO 20); o or a pharmaceutically acceptable derivative of any one thereof.

7. A compound of formula I, as defined in claim 1, or a pharmaceutically acceptable derivative thereof, for use as a pharmaceutical.

8. A compound of formula I, as defined in claim 1, or a pharmaceutically acceptable derivative thereof, for use in the manufacture of a medicament for the treatment of s obesity.

9. A pharmaceutical formulation comprising a compound of formula I, as defined in claim 1, or a pharmaceutically acceptable derivative thereof, in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier.

10. A method of improving the bodily appearance of a mammal which comprises 0 administering to that mammal a compound of formula I, as defined in claim 1, or a pharmaceutically acceptable derivative thereof, until a cosmetically beneficial loss of body weight has occurred.

11. A process for the preparation of a compound of formula I, as defined in claim 1, or a pharmaceutically acceptable derivative thereof, which comprises: s a) sulphating a compound of formula III,

wherein M, G and L are as defined in claim 1; Ja has the same definition as J in claim 1 except that the 0-carboxyl group of any Asp, DAsp, MeAsp or MeDAsp residue present is optionally protected; Xa has the same definition as X in claim 1 except that it may additionally represent Lys and any hydroxy or amino group is present in protected form (except for any hydroxy groups to be converted to a sulphate ester); and Za is NH₂ or a carboxyl protecting group; b) removing one or more protecting groups from a compound of formula IV,

wherein R¹, M, G, Xa, Ja, and Za are as defined in process alternative (a), and at least one of Xa, Ja, and Za comprises a protecting group; c) reacting a compound of formula V,

wherein M, G, J and L are as defined in claim 1, and Xb is Lys, with a compound of formula VI,

wherein R³, R⁴, R⁵, R⁶ and R⁷ are as defined in claim 1, to give a corresponding compound of formula I in which X is Lys(R²) and E is NH; or d) coupling a compound of formula V as defined in process alternative (c) with a compound of formula VU,

V I I

wherein E is CH₂CH₂ or CH=CH and R³, R⁴, R⁵, R^δ and R⁷ are as defined in claim 1, to give a corresponding compound of formula I in which X is Lys(R²) and E is CH₂CH₂ or CH=CH.

12. An intermediate compound of formula IV, as defined in claim 11.