IE913120A1 - Enzyme inhibitors - Google Patents

Abstract

Kininogenase inhibitors, optimally not exceeding the size of a hexapeptide, represented by (II), wherein A and B = amino acyl (including amino acyl analogue) the same or different forming a dipeptide group the amino acid of A carrying a terminal group and being any amino or imino-acid residue (but preferably of D-configuration) and of B being a lipophilic amino-acid residue of D- or L-configuration but not proline or a proline analogue, or a conformational analogue of said dipeptide group wherein the peptide link is replaced by -CH2-NH- ('reduced'), -CH(OH)-CH2- ('hydroxy'), -CO-CH2 ('keto'), -CH2-CH2- ('hydrocarbon') or other conformational mimic of the peptide bond and in (III) the side chain R<1> is that of a basic amino acid or amino acid analogue (preferably of L-configuration), and R is H or lower alkyl(C1-C4) or C< alpha > or the peptide link comprising -N(R)- is replaced leading to a conformational mimic as above; Y = a binding enhancing or carbonyl activating group preferably selected from H (when A or B must be cyclohexylalanine, preferably D if at A or L if at B) or alkyl (C1-C20) or fluoroalkyl (C2-C12); substituted oxymethylene; thiomethylene; sulphoxymethylene; sulphonylmethylene; aminomethylene; hydrazino-methylene; -CH2-Het (where Het = a substituted or unsubstituted heterocycle); substituted amino (but when the resulting compound is a secondary alkylamide B must not be phenylalanine); an amino-acid group or its ester or amide; a carboxylic secondary amide or primary amide, when B must be cyclohexylalanine or adamantylalanine or other bulky lipophilic, non-aromatic amino-acid (not Ala Leu Ile Val Nva Met Nle Phe Tyr Trp Nal (1)); tertiary-carboxamide; carboxy-alkyl group or its ester or amide or amino acyl derivative.

Description

The invention relates to enzyme inhibition and to treatment of disease.

BACKGROUND - KININS Kinins are natural vasoactive peptides liberated in the body from high molecular weight precursors (kininogens) by the action of selective proteases known as kininogenases.

There is evidence for the involvement of kinins in the following pathological states: (a) Conditions associated with vasodilatation and hypotension, e.g. septic, anaphylactic and hypovolaemic shock; carcinoid syndrome and dumping syndrome (b) Conditions involving inflammation, e.g. acute arthritis, pancreatitis, local thermal injury, crush injury and brain oedema ζu) Conditions involving bronchoconstriction, especially for example the initial, acute allergic reaction in asthma (d) Allergic inflammation, particularly allergic rhinitis and conjunctivitis, together generally known as hay fever, and the bronchial inflammation and consequent occlusion found in the non-acute but serious and even fatal inflammatory phase of asthma.

The kinins (bradykinin, kallidin and Met-Lys-bradykinin) are potent mediators of inflammation. Their main actions are as follows: (a) They increase capillary permeability which leads to exudate formation and oedema (b) They are potent vasodilators in arterioles and therefore reduce blood pressure and increase blood flow (c) They induce pain (d) They contract bronchial smooth muscle (e) They activate phospholipase A2 and thus stimulate the biosynthesis of prostaglandins (PG's) which mediate some of their actions.

In regard to prostaglandins, it may be noted that certain actions of kinins, particularly pain and vascular permeability above, are potentiated by PG's, although PG's themselves do not cause pain nor do they induce vascular permeability at the concentrations found in inflamed tissue. PG's therefore act as either mediators or potentiators of kinins.

In spite of the above knowledge of kinins and their actions, relatively little attention has been paid to reduction of their action. In asthma treatment for example clinical attention is primarily directed to the acute bronchoconstrictive reaction, for which there are effective drugs. Deaths continue to occur from the gradually developing bronchial occlusion, and at present not only are there no clinically effective inhibitors of kinin release available but the concept of kinin release inhibition, at least in treating allergic inflammation, appears to be new. The only substance that is in fact a kinin release inhibitor and has attained clinical significance is aprotinin ('Trasylol', Bayer, trade mark), a proteinase inhibitor isolated from bovine tissues (lungs, lymph nodes and pancreas). It is a strongly basic protein (pi = 10.5) of MW = 6,500 comprising a single peptide chain of 58 residues. However, aprotinin is primarily a trypsin inhibitor (Ki = 10~13M) and is some 106-times less active against kinin release. It has been found marginally beneficial in acute pancreatitis, a serious condition, where it inhibits the activation by trypsin of zymogens of pancreatic serine proteinases, and in traumatic - haemorrhagic shock. Aprotinin has to be administered parenterally, and it frequently produces a painful reaction at the injection site.

BACKGROUND - KININOGENASES The kininogenases are serine proteinases, that is to say proteinases in which the hydroxy group of a serine residue is the nucleophile involved in forming the substrate transition state. They liberate the kinins (bradykinin, kallidin) from the kininogens by limited proteolysis. There are several kinds of kininogenase:(a) Tissue kallikrein (TK, also called glandular kallikrein GT or urinary kallikrein UK) which is found in the pancreas, salivary glands, intestines, kidney and urine. It has MW = 30,000 and acts preferentially on low molecular weight kininogen (LMWK) to release the kinin kallidin (KD). Tissue kallikrein has no potent and fast acting endogenous inhibitor present in plasma. (b) Plasma kallikrein (PK) occurs in plasma as an inactive zymogen which is activated by Factor Xlla, and is part of the intrinsic coagulation cascade. It has MW = 100,000 and its preferred substrate is high molecular weight kininogen (HMWK) from which it releases bradykinin (BK). Plasma kallikrein is rapidly and effectively inhibited in plasma, by endogenous inhibitors known as cl-inactivator and a2-macroglobulin. (c) Mast cell tryptase which, while not as active as the kallikreins in kinin release, we have found to occur in large amounts in the mast cells of the lung tissue of asthmatics.

BACKGROUND - KININOGENS The kininogens which are the natural substrates for the kininogenases (they act also as potent inhibitors, Ki approx. 10 “ 11, of cysteine proteinases such as cathepsins Β, H and L, calpain and papain) occur in two types: (a) Low molecular weight kininogen (LMWK) with molecular weight in the range 50,000 - 70,000 depending on species of origin and degree of glycosylation. (b) High molecular weight kininogen (HMWK) with molecular weight in the range 88,000 - 114,000 which, in addition to serving as an alternative precursor of kinins and a cysteine proteinase inhibitor, also plays an obligatory role with plasma kallikrein in the initiation of the intrinisic coagulation cascade.

The two kininogens, whose mRNA's are transcribed from the same gene, have identical primary sequences throughout the Nterminal or heavy chain (H-chain) region, the kinin region and the first twelve amino acids of the C-terminal or light chain (L-chain). At this point their structures diverge, HMWK having a longer L-chain (MW approximately 45K) than LMWK (4.8K).

The cleavage of human HMWK by plasma kallikrein is for example shown schematically in Fig. 1, with details of the sequence at the cleavage sites in Fig. 2 and a more detailed sequence in Fig. 3 where the conventional numbering of residues adajcent to a cleavage site is shown for cleavage site I. After excision of one or other kinin sequence, the H- and L-Chains are held together by a single disulphide bridge:IE 913120 S - S· S - S H-chain BK L-chain HMWK Μ00Κ ΡΚΜ00Κ H-chain L-chain ure Cleavage BK IK MV/K by PK: Overall serene TK — lie -Ser-Leu -Met Cleavage site ΠΙ PK 4Cleavage site II PK 4TK •LysfC^rg-Pro-Pro-GIy-Phe-Ser-Pro-Phe-ArgySer-Ser-Arg-ne-Gi 380 Brady kinin - Kallidin — Cleavage site i Figure 2. Cleavage of human kininogens by PK and TK: Details of sequence ΡΚ,ΤΚ P4 P3 P2 -Phe-Ser-Pro-Phe-Arg 385 389 Pi P2 ?3 P4 P5 Ser-Ser-Avg-lie—Gly390 394 Figure 3. Sequences flanking cleavage site I in human HMWK As shown, plasma kallikrein and tissue kallikrein act at a single site to free the kinin C-terminal site, cleaving between residues 389 and 390, but at sites one residue apart, either side of residue 380 , to free the N-terminal of bradykinin (by PK) or kallidin (by TK).

The role of PK and HMWK as clotting factors in the intrinsic cascade does not involve the enzymatic release of kinins. However many of the effects of PK and all those of TK do involve such release, being mediated by the kinins released from the respective substrates HMWK and LMWK through selective proteolysis.

INDICATIONS The main clinical indications for kininogenase inhibitors are inflammatory conditions, particularly allergic inflammation (e.g. asthma and hay fever). A fuller list of indications is given below: (1) Allergic inflammation (e.g. asthma, rhino-conjunctivitis [hay fever], rhinorrhoea, urticaria (2) Inflammation (e.g. arthritis, pancreatitis, gastritis, inflammatory bowel disease, thermal injury, crush injury, conjunctivitis ) (3) Smooth muscle spasm (e.g. asthma, angina) (4) Hypotension (e.g. shock due to haemorrhage, septicaemia or anaphylaxis, carcinoid syndrome, dumping syndrome) (5) Oedema (e.g. burns, brain trauma, angioneurotic oedema whether or not as a result of treatment with inhibitors of angiotensin converting enzyme) (6) Pain and irritation (e.g. burns, wounds, cuts, rashes, stings, insect bites) STATEMENT OF INVENTION In one aspect the invention provides a method of treatment (including prophylactic treatment) of an inflammatory or other condition set out in the indications above, particularly an allergic inflammatory condition, wherein an effective amount of a peptide or peptide-analogue kininogenase inhibitor is administered topically or systemically to a patient suffering from or at risk of the condition. It is believed that for optimum activity, administrability and stability in the body the compounds should not exceed the size of a hexapeptide, that is to say should not comprise more than six amino acid or amino acid analogue residues; the presence of further residues, particularly in a pro-drug from which residues are cleaved in the body to give the compound primarily exerting the desired effect, is however not excluded.

Particularly, the invention provides a method of treatment of the allergic inflammatory phase of asthma, wherein an effective amount of a kininogenase inhibitor such as a mast cell tryptase inhibitor is administered topically or systemically to a patient suffering from or at risk of the condition.

The invention extends further to a method of preparation of a medicament for the topical or systemic treatment (including prophylactic treatment) of conditions as above particularly for allergic inflammatory conditions and especially for asthma as above, wherein a kininogenase inhibitor is associated with a pharmaceutically acceptable diluent or carrier to constitute said medicament.

In the above, the kininogenase inhibitor is conveniently but not essentially of the novel kind now described in which in another aspect, without limitation to any particular clinical indication, the invention provides synthetic, low molecular weight compounds that selectively inhibit kininogenases and thus block the release of kinins from kininogens. The inhibitors are peptide analogues, desirably (as above) not exceeding the size of a hexapeptide in terms of amino acid or analogue residues, based on the known amino acid sequence of the kininogens at cleavage site I, which analogues have sufficient similarity to the cleavage site sequence to bind to the active site of the kininogenase but are not hydrolysable and therefore remain bound, inactivating the enzyme.

The inhibitors are essentially of the structure below, in which A represents the P3 residue, B the P2 residue, C the Ρ3 residue and Y a carbonyl-activating or binding group the structure being:A-B-C-Y I where A, B and C are amino acyl or amino acyl analogue groups linked by peptide bonds or conformational analogues thereof giving a peptide mimic. Other residues in addition to these essential ones may of course be present, including amino acyl or amino acyl analogue residues.

In more definitive terms the compounds are represented by wherein A and B = amino acyl (including amino acyl analogue) the same or different forming a dipeptide group the amino acid of A optionally carrying a terminal group (other than hydrogen) and being any amino or imino-acid residue (but preferably of Dconfiguration) and of B being a lipophilic amino-acid residue of D- or L-configuration but not proline or a proline analogue, or a conformational analogue of said dipeptide group wherein the peptide link is replaced by -CH2-NH- ('reduced'), -CH(OH)-CH2('hydroxy'), -CO-CH2- ('keto'), -CH2-CH2('hydrocarbon') or other conformational mimic of the peptide link and in:IE 913120 R' i x the side chain R1 is that of a basic amino acid or amino acid analogue (preferably of Lconfiguration) and R is H or lower alkyl (C^ C4) or Ca or the peptide link comprising -N(R)- is replaced leading to a conformational mimic as above. For example Ca may be replaced by nitrogen.

Y = a binding enhancing or carbonyl activating group for example selected from H (but only if A or B is cyclohexylalanine, preferably D if at A or L if at B) or alkyl (C-[_ - C20) or fluoroalkyl (C2 - C12); substituted oxymethylene; thiomethylene; sulphoxymethylene; sulphonylmethylene; aminomethylene; hydrazino-methylene; -CH2-Het (where Het = a substituted or unsubstituted heterocycle); substituted amino (but when the resulting compound is a secondary alkylamide B must not be phenyl-alanine); an amino-acid group or its ester or amide; a carboxylic secondary amide or primary amide, when B must be a bulky lipophilic, non-aromatic amino-acid e.g. cyclohexylalanine, adamantylalanine (not Ala Leu lie Val Nva Met Nle Phe Tyr Trp Nal (1)); tertiary-carboxamide; carboxy-alkyl group or its ester or amide.

In the above context substituents are suitably common functional groups that increase binding affinity to the enzyme and/or improve pharmacological properties. Further in considering conformational analogues or mimics a dipeptide mimic is a structure containing non-natural amino acid (amino acid analogue) residues or which is non-peptidic and which in I holds the side-chains of A and B or B and C or all of them in a conformation similar to that present in the parent peptide when bound to the active site of the enzyme. It may also contain features favourable for other interactions with the enzyme, e.g. hydrogen bonding. A mimic may be chosen from the published work on such analogues.

For example, the following are mimics of the dipeptide DPro-Phe (Ph may be replaced by -CH2Ph):- 0k N N H H CO,H Ph ( i) 1 Reduced 'mimic nydroxyetnylene mimic (in) 'Keto' or ketcmetr.y lene mimic (iv) (v) (vi) ('Hydrocarbon' mimic) Figure 4, DPro-Phe mimics The preferred compounds represented by the above general formula are now considered.

Preferred residues for A are imino-acids, (e.g. D-proline or an analogue of proline e.g. pipecolinic acid, azetidine carboxylic acid etc.); lipophilic amino acids (e.g. DPhe, DCha, DChg); strongly basic amino acids (e.g. D-Arg or a guanidinophenylalanine) and for B they are L-Phe, L-Cha, L-aNal, L-Tal, L-(4F)Phe L-(NMe)Phe or other substituted phenylalanines. A and B may also be the N-alkyl (C-l—C4) or Ca-alkyl (C^-Cy e.g. methyl, benzyl) analogues of these amino acids. Suitable terminal groups for A include lower alkyl (preferred) or acyl (not excluding amino acyl), alkyl sulphonyl (straight chain or branched or cyclic), amino-alkyl, carboxy alkyl, hydroxy alkyl or any other common protecting group encountered in peptide chemistry.

Groups suitable as group Y are specific to the present invention in that they are part of the structure giving the required binding to the active site and are not merely noninterfering end groups. They form a binding group which increases affinity to the enzyme and/or a group which activates the adjacent carbonyl by rendering it more electrophilic. Specific groups are included in the following formula: R1 IV where in a peptide link to residue B the α-nitrogen may be free or substituted for example by methyl or other C-^-C^ alkyl . 1 and thus R and R are as before but particularly R = 3-guanidinopropyl or other guanidinoalkyl group or an amidinoalkyl or aminoalkyl group, also para- or meta substituted guanidino or amidino-benzyl or protected forms of the above (the basic nitrogens may also be alkylated e.g. with Me, Et), and where Y = groups as given below, first in more general terms and then in terms of more detailed preferences, subject in both cases to the provisos expressed in defining the compounds of the invention earlier. The detailed preferences are given in groups under roman numerals, which are also indicated, in brackets, with the first listing which is:(I) Y = H (representing aldehydes) or alkyl including fluoroalkyl (representing ketones) (II-III-IV) Y = -ch2q where Q = -OR2 or -SR2 or -SOR2 or -SO2R2 or -NHR2 or - N or ^R5 (note that -dJ represents a ring in which D is an atom of that ring) wherein R2, R4 and R5 are as below (ν-vr Y = -ch2 chr6 con or -ch2 chr6 co-d) wherein R4 , R5 and R6 are as below (VII-VIII) Y = amino acyl or a group forming a substituted amide or hydrazide (IX-X-XI) Y = a group forming an α-keto amide e.g.

- COR 9 or -CO-D or R4 and in which further:R2 = alkyl or substituted alkyl including aryl or aryl alkyl and -CH2R3 where R3 = fluoroalkyl R4 and R5 the same or different but not both hydrogen = H or C^-C20 alkyl (which may be further substituted), acyl or alkyl sulphonyl -3 is a heterocyclic ring (D = nitrogen or carbon in Group IV and N in Groups VI and X) optionally unsaturated and optionally with further hetero atoms and substituents R6 = hydrogen, alkyl, hydroxyalkyl, aminoalkyl, alkylaminocarbonyl R9 = -NH2 as such or alkylated, or amino acyl The listing of more detailed preferences, again within the provisos expressed earlier, is:Group I Y - H; alkyl including branched alkyl (ci-c2o); aryl alkyl? or cycloalkyl (C1-C2Q); perfluoroalkyl or partially fluorinated alkyl (C2-C12); [e.g. Y = Me; -CH(CH2CH2CH2CH3)2 ; -CH(CH2CH2 CH2 CH3)CH2-eyelohexy1; -CH2CF2CF2CF3; -CF2CH2CH2CH3].

Group II Y = -CH2QR2 where Q = 0, S, SO, SO2, NH and where R2 = Alkyl, branched alkyl or acyl (Ci-C12); or cycloalkyl (C3-C20)? or aryl or aryl alkyl; or -CH2-R3 where R3 = perfluoroalkyl or partially fluorinated alkyl, branched or not (C1-C12).

Group III -CH2N x;' ^R5 R4, R5 the same or different = alkyl, branched alkyl, cycloalkyl, acyl, alkylsulphonyl, carboxyalkyl (the carboxyl group may be further derivatized to form an ester or amide with an amino-acid or dipeptide), carbamoyl, sulphamoyl, N-dialkylamino-, arylalkyl, haloalkyl including fluoroalkyl, cyanoalkyl, alkoxyalkyl, hydroxyalkyl, mercaptoalkyl, aminoalkyl and derivatives thereof e.g. esters, amides and thioesters; or one of R4 or R5 = hydrogen Group IV Ϊ = -=»2 - 3 where D = nitrogen or carbon and -dJ is a saturated or unsaturated heterocyclic ring or a bicyclic ring system, each is 5 - 8 membered, where there may be other heteroatoms (N, S, 0) and carbons or nitrogens may optionally be substituted by alkyl, branched alkyl, cycloalkyl, carboxyalkyl, carboxy (attached to carbon), amino, alkoxy, alkoxymethyl or (carbon) as carbonyl or other groups beneficial for interaction with the enzyme.

Group V Y = -CH2CH(R6)CONR4R5 R4, R5 as defined in Group III.

R6 = hydrogen lower alkyl, branched alkyl, cycloalkyl, hydroxyalkyl, amino-alkyl, alkylaminocarbonyl.

Group VI Y = -CH2CH(R6)CO^ R6 as defined in Group V and - D) as defined in Group IV (but with D = N) Group VII Y = an amino-acid residue or any amide (secondary or tertiary) or ester of that residue, L or D configuration. Preferred residues are of lipophilic amino-acids e.g. norleucine, cyclohexylalanine, homocyclohexylalanine,cyclohexylglycine,tertbutylglycine.

Group VIII Y = - N-R8 β R = H (when however B is not phenylalanine unless R° is carboxylalkyl or derivatized carboxylalkyl); or alkyl, branched alkyl (Cj^ - C12) , cycloalkyl (C1-C20) carboxyalkyl or bis ( carboxyl ) alkyl , which may be derivatized at the carboxyl group to form an amide e.g. with an amino-acid (preferred is arginine) or a substituted amine; N'-dialkylamino; Ν'-alkylamino-; Q 7 R = R the same or different but excluding H.

Group IX Y = -CO-R9 but only if B is a bulky non-aromatic lipophilic amino acid or its N? alkyl (C^ - C4 ) derivative (e.g. cyclohexylalanine but excluding Ala, Leu, lie, Val, Nva, Met, Nle, Phe, Tyr, Trp, Nal(l) and their N-methyl derivatives) where R9 = nh2, Ν'-alkylamino (where the alkyl groups include branched and/or cycloalkyl); an amino-acid residue.

Group X -d) as defined in Group IV (but D = N) Group XI Y = -CO-NR4R5 R4,R5 as defined in Group III, but not H The following examples illustrate the invention. They are given in the form of:Nine tables of compounds with reference number, structure, molecular ion as determined by FAB (fast atom bombardment) spectrometry and class of compound (the same as the 'groups' referred to earlier herein) Eight detailed examples of synthesis Twelve synthesis schemes, as referred to in the detailed examples Table of abbreviations Description of in vitro tests of inhibition of kininogenases and in vivo tests of efficacy against asthma All structures of intermediates were verified by NMR.

TABLE I Aldehydes [M+H]+ Class Me-DPhe Cha Arg-H 473 I TABLE 2 Thiomethylene Analogues and Sulphomethylene Analogues [M+H]+ Class 17 H-DPro Phe Arg CH2S(CH2)4Me 519 Π 60 H-DPro Phe Arg CH2SnBu 505 Π 61 H-DPro Phe DLArg CH2SO2nBu 537 Π TABLE 3 Ethers [M+H]+ Class 23 H-DPro Phe Arg CH2OCH2(CF2)3CHF2 647 II 62 Η-Pro Phe Arg CH2OCH2CF3 515 Π 63 Boc-DPro Phe DLArg CH2OCH2CF3 615 H 64 H-DPro Phe DLArg CH2OCH2CF3 515 Π 65 H-DPro Cha DLArg CH2OCH2CF3 521 II 66 H-DPro Phe Arg CH2OCH(Me)CF2CF2CF3 629 Π 67 H-DPro Phe Arg CH2OCH2CF3 515 II 68 H-DCha Phe Arg CH2OCH2CF3 571 II 69 H-DArg Phe Arg CH2OCH2CF3 574 II 70 H-DChg Phe Arg CH2OCH2CF3 557 II 54 H-DPro Phe Arg CH2O(CH2)5CH3 517 II 55 H-DPro Phe Arg CH2OPh 509 II TABLE 4 Aminomethylene and related analogues [M+H]+ Class 31 H-DPro Phe Arg CH2N[(CH2)5Me]2 600 m 71 H-DPro Phe DArg CH2(RS)Tha 556 IV 72 H-DPro Phe Arg CH2(RS)Tha 556 IV 73 H-DPro Phe Arg CH2 l-Pip-3-(RS)CO2Et 572 IV 74 H-DPro Phe DLArg CH2 l-Pip-3-(RS)CH2O(CH2)3Me 586 IV 75 H-DPro Phe DLArg CH2 l-Pip-3-(RS)CH2NEt2 585 IV 76 H-DPro Phe DLArg CH2 l-Pip-3-CONEt2 599 IV 77 H-DPro Phe DLArg CH2 l-Pip-3-(RS)CONHnBu 599 IV 78 H-DPro Phe DLArg CH2 l-Pip-3-(RS)CON(nBu)2 655 IV 79 H-DPro Phe DLArg CH2 l-Pip-4-(l’-Pip) 583 IV 80 H-DPro Phe Arg CH2(NMe)AhaNHnBu 615 IV 81 H-DPro Phe Arg CH2-Abn 540 IV 82 H-DPro Phe Arg CH2-Hyp(OnBu)NHEt 629 IV 83 H-DPro Phe Arg CH2-Sar Pro NHEt 628 ΠΙ 84 H-DPro Phe Arg CH2-*Hyp(OnBu)BOnBu 644 IV 85 H-DPro Phe DLArg CH2Pic NEt2 641 rv 86 H-DPro Phe DLArg CH2tDHyp(OnBu)ROnBu 644 IV 87 H-DPro Phe DLArg CH2ProRCONEt2 599.9 IV 88 H-DPro Phe DLArg CH21-Pip-3(RS)CO2H 544 IV 89 H-DPro Phe Arg CH2l-Pip-3(RS)CH2CONEt2 613 IV 90 H-DPro Phe Arg CH2N(CH2Ch)(CH2)5Me 612 ΠΙ 91 H-DPro Phe DLArg CH2N(Oc)2 657 ΠΙ 92 H-DPro Phe Arg CH2N(Et)Ch 542 ΠΙ 93 H-DPro Phe Arg CH2N(Me)(CH2)4NH2 517 m 94 H-DPro Phe Arg CH2N(Me)nBu 502 HI 95 H-DPro Phe DLArg CH2NnBu2 544 ΠΙ 96 H-DPro Phe DLArg CH2N[Bu]SO2nBu 594 ΠΙ 97 H-DPro Phe DLArg CH2NPBu](CH2)3CONH2 573 m 98 H-DPro Phe DLArg CH2N[nHex](CH2)7NH2 629.5 HI 99 H-DPro Phe DLArg CH2NPHex](CH2)5NH2 601 HI 100 H-DPro Phe DLArg CH2NPHex](CH2)3NH2 573 HI 101 H-DPro Phe DLArg CH2NPBu](CH2)4Ph 620 m 21 TABLE 4 (cont) Aminomethylene Ketones and related analogues Class [M+H]+ 102 H-DPro Phe DLArg CH2N[nHex](CH2)6CONH2 643 ΠΙ 103 H-DPro Phe DLArg CH2NPHex](CH2)6NH2 615 ΠΙ 104 H-DPro Phe DLArg CH2N|nHex](CH2)7OH 630 ΠΙ 105 H-DPro Phe DLArg CH2N[nHex](CH2)7NHAc 671 ΠΙ 106 H-DPro Phe DLArg CH2N[nHex](CH2)6CONHEt 671 ΠΙ 107 H-DPro Phe DLArg CH2N[nHex](CH2)6CO2Me 658 ΠΙ 108 H-DPro Phe DLArg CH2N[nHex](CH2)6CO2H 644 ΠΙ 109 H-DPro Phe DLArg CH2N[nBu](CH2)3CONEt2 629 ΠΙ 110 H-DPro Phe DLArg CH2N[nBu](CH2)3CONHEt 601 ΠΙ TABLE 5 Keto Isostere Containing Analogues [M+H]+ Class 40 H-DPro Phe DLArg^ly Pro-NHEt 599 VI 111 H-DPro Phe ArgKGly Pro-NHEt 599 VI 112 H-DPro Phe Arg^ly Arg-NH2 530 V 113 H-DPro Phe DLArg^Gly Ala-NH2 545 V 114 H-DPro Phe DLArg^Gly Aha-NH2 587 V 115 H-DPro Phe DLArgRlly Aha-NHBu 643 V TABLE 6 Substrate Analogues [M+H]+ Class 45 H-DPro Phe ArgChg-NH2 557 vn 116 CPr-CO Phe Arg Chg-NH2 * VII 117 MeSO2 DPro Phe Arg Chg-NH2 635 VII 118 MeCO DPro Phe ArgChg-NH2 599 VII 119 H-DArg Phe Arg Ser- NH2 * VII 120 H-DCha Phe Arg Ser- NH2 * VII 121 H-DPhe Phe Arg Ser- NH2 * vn 122 H-DPic Phe Arg Ser- NH2 * vn TABLE 6 (cont.) Substrate Analogues [M+H]+ Class 123 H-DPic Phe Arg Chg-NH2 * VII 124 H-DPro Phe Arg Ser-NH2 * VII 125 H-DPro Cha Arg Ser-NH2 * VII 126 H-DPro Cha Arg Gly-NH2 * VII 127 H-DPro Phe Arg Ser-Arg-NH2 * VII 128 H-DPro Phe Arg Lys-NH2 * vn 129 H-DPro Phe Arg Aha-NH2 * vn 130 H-DPro Phe Arg Phe-NH2 565 vn 131 H-DPro Phe Arg Leu-NH2 531 vn 132 H-DPro Phe Arg He-NH2 531 vn 133 H-DPro Nal Arg Ser-NH2 * vn 134 H-DPro Phe Arg DAha-NH2 531 vn 135 H-DPro Phe Arg Aha-NH(CH2)3Me 587 vn 136 H-DPro Phe Arg Nleucinol 518 vn 137 H-DPro Phe Arg SeiCPBu NH2 561 vn 138 H-DPro Phe Arg Cha-NH2 571 vn 139 H-DPro Phe Arg Ada-NH2 623 vn 140 H-DPro Phe Arg Hch-NH2 585 VII 141 H-DPro Nal Arg Cha-NH2 * VII 142 H-DPro Cha Arg Cha-NH2 * VII 143 H-DPro PhepNO2Arg Ser-NH2 * VII 144 H-DPro Nal Arg Ile-NH2 * VII 145 H-DPro Phe Arg He Pro-NH2 * vn 146 H-DPro Phe Arg Aha Pro-NH2 * VII 147 H-DPro Nal Arg Aha-NH2 * VII 148 H-DPro Cha Arg Npg-NH2 * VII 149 H-DPro Cha Arg Hch-NH2 * VII 150 H-DPro Nal Arg Hch-NH2 * VII 151 H-DPro Phe Arg Npg-NH2 545 VII 152 H-DPro Phe Arg Chg-l-Pip 625 VII 153 H-DPro Phe Arg Chg-NH(CH2)5Me 641 vn 154 H-DPro 4-Fph Arg Chg-NH2 575 vn * Satisfactory amino acid analysis obtained TABLE 7 Amides [M+H]+ Class 47 H-DPro Phe Arg N[(CH2)5Me](CH2)3Ch 626 vni 155 H-DPro Phe Arg N(Me)nBu 488 vni 156 H-DPro Phe Arg NH(CH2)3CO Arg-NH2 * vni 157 H-DPro Phe Arg NH(CH2)3NH2 475 vni 158 H-DPro Phe Arg NH(CH2)4CO Arg-NH2 * vni 159 H-DPro Phe Arg NH(CH2)4NH2 * vni 160 Η-Pro Phe Arg NH(CH2)5CO Arg-NH2 687 vni 161 H-DPro Phe Arg NH(CH2)5NH2 503 vni 162 H-DPro Phe Arg NH(CH2)6CO Arg-NH2 701 vni 163 H-DPro Phe Arg NH(CH2)7CO Arg-NH2 715 vm 164 H-DPro Phe Arg NH(CH2)7CONH(CH2)3Me 615 vni 165 H-DPro Phe Arg NH(CH2)7NHAc 573 VIII 166 H-DPro Phe Arg NH(CH2)7NH2 531 vni 167 H-DPro Phe Arg NH(CH2)7CONH2 559 vni 168 H-DPro Phe Arg NH(CH2)7CO-Gly Gly Arg-NH2 829 vni 169 H-DPro Phe Arg NH(CH2)7CO-Gly Arg-NH2 772 vni 170 H-DPro Phe Arg NH(CH2)7CO-Gly Gly-Gly Arg-NH2 886 vni 171 H-DPro Phe Arg N[nHex]2 586 vni 172 H-DPro Cha Arg NHCH2Ch 520 vni 173 H-DPro aNal Arg NHCH2Ch 564 vni 174 H-DPro PNal Arg NHCH2Ch 564 vni 175 H-DPro His Arg NHCH2Ch 504 vni 176 H-DPro(4Me)Phe Arg NHCH2Ch 528 vni 177 H-DPro Phe Nar NHCH2Ch 500 vni 178 H-DPic Phe Arg NHCH2Ch 528 vni 179 H-DTic Phe Arg NHCH2Ch 576 vni 180 H-DThi Phe Arg NHCH2Ch 570 vni 181nBu DPro Phe Arg NHCH2Ch 570 vm * Satisfactory amino acid analysis obtained TABLE 8 Ketones [M+H]+ Class 49 H-DPro Phe Arg CH3 417 I 48 H-DPro Phe Arg(CF2)2CF3 ** I 53 H-DPro Phe ArgCH2CH[nHex]2 *** I ** Molecular ion not detected TABLE 9 a-Ketoamides [M+H]+ Class 11 H-DPro Phe DL Lys CON[nBu]2 530 XI 50 H-DPro Cha DL Arg CON[“Bu]2 *** XI *** [M+H]+ not available EXAMPLE I Me-DPhe-Cha-Arg-H The synthesis of 5 was carried out according to Scheme I. Arabic numerals underlined e.g. I refer to structures in these schemes. Roman numerals in parentheses e.g. (i) refer to reaction steps. (i) Isobutyl chloroformate (10.2 mmol) was added to a solution of Boc-Arg(Z2)OH (9.23 mmol) and N-methylmorpholine (11.08 mmol) in dry THF (25 cm3) at -20°C. After 20 mins the solid was filtered off and the filtrate added to a solution of sodium borohydride (10.3 mmol) in water (10 cm3) at 0°C. After 3 hours 0.3 M KHSO4 was added, the crude product extracted with EtOAc and purified by flash chromatography on silica with EtOAc - petrol (4:6). The alcohol J. was isolated as a white solid (97%). (ii) The Boc group of 1, (4.75 mmol) was removed with sat. HCl/Dioxan and the product acylated with Boc-Cha-ONSu (9.5 mmol) in CH2C12 (20 cm3) at 0°C in the presence of N-methylmorpholine. After two hours the reaction was worked up using standard procedures and the crude product purified by flash chromatography on silica with EtOAc - petrol (4:6). The pure alcohol 2 was isolated as a colourless oil (90%). (iii) The Boc group of 2 (4.27 mmol) was removed with sat. HCl/Dioxan and the product reacted with Z(NMe)DPhe-OH (5.12 mmol) in the presence of HOBt (10.2 mmol), water soluble carbodiimide (6.1 mmol) and N-methylmorpholine in DMF (20 cm3) at 0°C. After 18 hours the reaction was worked up using standard procedures and the product purified by flash chromatography on silica with EtOAc petrol (1:1). The pure alcohol 3 was isolated as a colourless oil (52%). (iv) The alcohol 3 (2.22 mmol) was dissolved in CH2C12/AcOH (30:1) and Dess-Martin Periodinane (4.5 mmol) added. After 2| hours at room temperature the reaction mixture was diluted with EtOAc and poured into a solution of sodium thiosulphate (32 mmol) and sat. NaHCO3. The crude product was purified by flash chromatography on silica with EtOAc-petrol (3:7). The pure aldehyde 4 was isolated as a colourless oil (75%). (v) The aldehyde 4 (1.65 mmol) was dissolved in MeOH/H2O/AcOH (90:9:1, 50 cm3) and hydrogenated over 5% Pd/C. The crude material was purified by mplc on *Vydac Ο}8 (15-25 μ) using MeCN/H2O/TFA to give pure 5 (CH-851) as a white solid (780 mg). Tic, EtOAc-Py-AcOH-H2O (30:20:6:11), Rp 0.66 on silica. After hydrolysis at 110°C/22 hrs with 6N HC1 peptide content based on Cha was 40%. FAB mass spec [M+H]+ = 473 (Calc. m/z = 472).

EXAMPLE Π H-DPro-Phe-Lys-CONnBu2 (see Scheme II) (i) TcbocONSu (14.8 mmol) was added to a solution of H-Lys(Z)-OMe. HC1 (12.2 mmol) and triethylamine (14.8 mmol) in CH2C12 (50 cm3). After 3 hours at room temperature the reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc - petrol (7:13). The pure ester 6 was isolated as a colourless oil (100%). (ii) Diisobutylaluminium hydride (1.5 M solution in toluene, 50 mmol) was added to a solution of 6 (12.2 mmol) in dry toluene (100 cm3) at -78°C over a period of 20 minutes. After a further 15 minutes methanol (10 cm3) was added followed by a saturated solution of Rochelle’s salt (100 cm3). After 2i hours the reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc - petrol (3:7). The pure aldehyde 7 was isolated as a colourless oil (49%).

* Trade name (iii) Potassium cyanide (18 mmol) and 1 M hydrochloric acid (30 cm3) were added to a solution of 7 (5.98 mmol) in ethyl acetate (30 cm3). After 18 hours at room temperature the reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc - petrol (4:6). The pure cyanohydrin 8 was isolated as a colourless oil (88%). (iv) A 4 M solution of HC1 in dioxan (50 cm3) was added to a solution of 8 (5.28 mmol) in dry methanol (15 cm3) at O°C. After 18 hours at room temperature an ice/water mixture (15 cm3) was added. After 3 days at 4°C solid KHCO3 was added. The reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc - petrol (11:9). The pure ester 8b was isolated as a yellow oil (59%). (v) Activated zinc dust was added in small portions to a solution of 8b (3.1 mmol) in AcOH/H2O (9:1, 25 cm3). After Π hours at room temperature the zinc was filtered off, the filtrate evaporated in vacuo and the residue was taken up in EtOAc. This solution was washed with sat. NaHCO3, water, brine, dried (Na2SO4) and evaporated in vacuo. The amine 9 was isolated as a colourless oil (85%). (vi) The amine 9 (2.63 mmol) was acylated with Boc-Phe-ONSu (3.04 mmol) in CH2C12 (30 cm3) at O°C in the presence of N-methyl morpholine. After 3 hours the reaction was worked using standard procedures and the crude product purified by flash chromatography on silica with EtOAc/Pet Ether (6:4). The pure ester 10a was isolated as a colourless oil (92%). (vii) The Bex; group of 10a (2.41 mmol) was removed using sat. HCl/Dioxan and the product acylated with Boc-DPro-ONSu (2.92 mmol) in CH2C12 (30 cm3) at O°C in the presence of N-methyl-morpholine. After 3 hours the reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc/Petrol (3:1). The pure ester 10b was isolated as a colourless oil (64%). (viii) Lithium hydroxide (1.6 mmol) and water (3 cm3) were added to a solution of 10b (1.54 mmol) in THF (30 cm3). After 4 hours at room temperature the THF was removed in vacuo, the pH of the residue adjusted to pH 4 with 1 M citric acid and extracted with CHCI3. The organic extracts were washed with brine, dried (Na2SO4) and evaporated in vacuo. The pure acid 10c was isolated as a colourless oil (70%). (ix) Pentafluorophenol (1.3 mmol) and water soluble carbodiimide (1.3 mmol) were added to a solution of 10c (1.07 mmol) in CH2C12 (20 cm3) at O°C. After 2 2 hours dibutylamine (2.1 mmol) was added to this solution at O°C and the pH adjusted to pH 9 with DIEA. After 18 hours at room temperature the reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc/Petrol (7:3). The pure amide lOd was isolated as a colourless oil (48%). (x) Dess-Martin Periodinane (0.97 mmol) was added to a solution of lOd (0.52 mmol) in CH2C12 (100:1, 40 cm3). After 2 hours at room temperature further Dess-Martin Periodinane (0.52 mmol) was added. After a further 3 hours the reaction mixture was diluted with EtOAc and poured into a solution of sodium thiosulphate (7.3 mmol) in water and sat. NaHCO3 were added. The crude product was purified by flash chromatography on silica with EtOAc/petrol (9:11). The pure keto amide lOe was isolated as a colourless oil (57%). (xi) The Boc group of lOe (0.24 mmol) was removed using sat. HCl/Dioxan. The resultant product was dissolved in AcOH/H2O (9:1) and hydrogenated over 5% Pd/C. The crude material was purified by mplc on *Vydac C!8 (15 - 25 μ) using MeCN/H2O/TFA to give 11 (CH-1463 89.7 mg). Hplc, *Novapak C18, 4 μ (8 x 100 mm), linear gradient 20 —» 80% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 min at 1.5 ml min'1 indicates the presence of two epimers D-Arg (40%) at 11.2 min and L-Arg (60%) at 12.6 min. After hydrolysis at 110°C/22 h with 6N HCl, amino acid analysis Phe 0.93, Pro 1.07.

EXAMPLE III H-DPro-Phe-Arg-CH2S(CH2)4CH3 (see Scheme HI) (i) Boc-ArgiZ^OH (46.1 mmol) was dissolved in dry THF (200 cm3). N-methylmorpholine (50.85 mmol) and isobutyl chloroformate (50.73 mmol) were added at -20°C. After 20 min. this mixture was added to a solution of diazomethane (0.1 mole) in Et2O at -5 °C. After 2 hours the diazoketone 12 was isolated as a yellow solid. (ii) The diazoketone 12 (46.1 mmol) in dry THF was treated with HBr (69.15 mmol) in EtOAc at -20°C followed by addition of sat. NaHCO3 after 45 mins. The crude product was extracted with EtOAc and crystallised from EtOH to give pure Boc-Arg(Z2)CH2Br, 13, (85%). (iii) 1-Pentanethiol (1.27 mmol) in dry DMF (5 cm3) was treated with sodium hydride (1.4 mmol). After 30 mins Boc-Arg(Z2)CH2Br JJ (1.27 mmol) was added-40°C for 20 mins and -5°C for 21 hours. After addition of 0.3 M KHSO4 and extraction of the crude product with EtOAc, flash chromatograpy on silica with EtOAc - petrol (15:85) yielded the pure thiomethylene compound 14 as a colourless oil (74%).

* Trade name (iv) The Boc protecting group of 14 (0.94 mmol) was removed using sat. HCl/Dioxan and the resulting product was acylated with Boc-Phe-OPfp (1.13 mmol) in CH2C12 at O°C in the presence of DIE A. The crude product was purified by flash chromatography on silica with EtOAc - petrol (3:7) yielding the pure thiomethylene analogue 15 as a colourless oil (55%). (v) The Boc protecting group of 15 (0.52 mmol) was removed using sat. HCl/Dioxan. The resulting product was dissolved in DMF and treated with Boc-DPro-OH (0.63 mmol) in the presence of HOBt (1.05 mmol), water soluble carbodiimide (0.76 mmol) and N-methylmorpholine. After a standard work-up the crude material was purified by flash chromatography on silica with EtOAc - petrol (4:6) yielding the pure thiomethylene compound 16 as a colourless oil (74%). (vi) The Boc protecting group of 16 (0.38 mmol) was removed using sat. HCl/Dioxan. The resultant product was dissolved in AcOH/H2O (9:1) and hydrogenated over 5% Pd/C. The crude material was purified by mplc on *Vydac C18 (15-25 μ), using MeCN/H2O/TFA to give pure Γ7 (CH-574, 41 mg). Hplc, *Novapak Cjg, 4μ (8 x 100 mm), linear gradient 20 —* 80% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 min at 1.5 ml min1 indicates the presence of two epimers D-Arg (<5%) at 9.8 min and L-Arg (>95%) at 11.1 min. After hydrolysis at 150°C/1.5 h with 6N HCl, amino acid analysis Phe, 0.80; Pro, 1.00.

All analogues in Table 2 were synthesised by the described method. 61 was synthesised by the oxidation of 60 with metachloroperoxybenzoic acid.

* Trade name EXAMPLE IV H-DPro-Phe-Arg-CH2OCH2(CF2)3CHCF2 (see Scheme IV) (i) ΓΗ, IH, 5H-Octafluoro-1-pentanol (2.45 mmol) in dry DMF (8 cm3) was treated with sodium hydride (1.83 mmol). After 30 mins the bromoketone 13 (1.65 mmol) was added at -40°C and left at this temperature for 30 mins and -5°C for 21 hours. Addition of 0.3 M KHSO4 and extraction with EtOAc gave the crude product which was purified by flash chromatography on silica using EtOAc - petrol (15:85). The pure fluoroether 18 was isolated as a colourless oil (69%). (ii) The fluoroether 18 (1.13 mmol) was dissolved in MeOH (40 cm3), sodium borohydride (1.18 mmol) was added to this solution at 0°C. After 15 min 0.3 M KHSO4 was added and the mixture extracted with EtOAc giving the pure compound 19 as a colourless oil (88%). (iii) The Boc protecting group of 19 (1.0 mmol) was removed with sat. HCl/Dioxan. The resulting product was dissolved in CH2C12 and acylated with Boc-Phe-OPfp (1.2 mmol) in the presence of DIEA at 0°C. After a standard work up the crude product was purified by flash chromatography on silica with EtOAc - petrol (3:7) yielding the pure product 20 as a colourless oil (55%). (iv) 20 (0.55 mmol) was deprotected with sat. HCl/Dioxan and acylated with Boc-DPro-OPfp (1.63 mmol) in CH2Cl2 at 0°C in the presence of DIEA. After a standard work up the crude product was purified by flash chromatography on silica with EtOAc - petrol (4:6) yielding the pure product 21 as a colourless oil (48%). (v) 21 (0.24 mmol) was dissolved in CH2C12/AcOH (30:1) and Dess-Martin Periodinane (0.48 mmol) was added. After 2 hours at room temperature the reaction mixture was diluted with EtOAc and poured into a solution of sodium thiosulphate (3.5 mmol) in water and sat. NaHCO3. The crude product was purified by flash chromatography on silica with EtoAc - petrol (7:13) yielding the pure fluoroether 22 as a colourless oil (64%). (vi) The fluoroether 22 (0.16 mmol) was deprotected and purified as described in Example ΙΠ (vi). Pure 23 (CH-619) was isolated as a white solid (50.9 mg). Hplc, *Novapak C18 4μ (8 x 100 mm), linear gradient 20 —* 80% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 mins at 1.5 ml min'1 indicated a single product (Tr = 11.5 min). After hydrolysis at 150°C/1.5 hr with 6N HC1, amino acid analysis Phe, 1.00; Pro, 1.2.

All analogues in Table 3 were synthesised by the described method except 54 and 55 which were synthesised by methods outlined in Schemes ΧΠΙ and XIV respectively.

EXAMPLE V H-DPro-Phe-Arg-CH2N[(CH2)5CH3]2 (see Scheme V) DL (i) Boc-Arg(Z2)OH (18.5 mmol) was dissolved in CH2C12 (50 cm3). To this solution at 0°C was added trichloroethanol (20.35 mmol), water soluble carbodiimide (22.2 mmol) and dimethylaminopyridine (0.93 mmol). After 3 hours the reaction was worked up using standard procedures giving the pure trichloroethyl derivative 24 as a colourless oil (100%).

* Trade name (ii) 24 (18.1 mmol) was deprotected with sat. HCl/Dioxan and acylated with Boc-Phe-ONSu (27.2 mmol) in CH2C12 at 0°C in the presence of N-methylmorpholine. After 3 hours the reaction mixture was worked up using standard procedures and the crude product was purified by flash chromatography on silica with EtOAc - petrol (2:8) yielding the pure product 25 as a white solid (97%). (iii) 25 (17.4 mmol) was deprotected with sat. HCl/Dioxan and acylated with Boc-DPro-ONSu (26.2 mmol) in CH2C12 at 0°C in the presence of N-methylmorpholine. After 3 hours the reaction was worked up using standard procedures and the crude product purified by flash chromatography on silica with EtOAc - petrol (35:65) giving the pure protected tripeptide 26 as a colourless oil (94%). (iv) Activated zinc powder was added to a solution of 26 (16.47 mmol) in glacial acetic acid. After 3 hours at room temperature the zinc was filtered off, the filtrate evaporated and the crude product purified by flash chromatography on silica with EtOAc - petrol AcOH (74:25:1) giving the pure tripeptide 27 as a white solid (91%). (v) The protected tripeptide 27 (15 mmol) was dissolved in dry THF (40 cm3), N-methylmorpholine (18 mmol) and isobutylchloroformate (16.6 mmol) were added at -20°C. After 20 mins the mixture was added to a solution of diazomethane (35 mmol) in Et2O at -5°C. After 2j hours the diazoketone 28 was isolated as a yellow oil. (vi) The diazoketone 28 (15 mmol) in dry THF was treated with HBr (22.5 mmol) in EtOAc at -20°C followed by addition of sat. NaHCO3 after 45 mins. The crude product was extracted with EtOAc and purified by flash chromatography on silica with EtOAc petrol (1:1). The pure bromoketone 29 was isolated as a white solid (72%). (vii) Dihexylamine (1.25 mmol) and NaHCO3 (0.8 mmol) were added to a solution of bromoketone 29 (0.23 mmol) in dry THF (5 cm3). After 18 hrs at room temperature 0.3 M KHSO4 was added to the reaction mixture and the crude product was purified by flash chromatography on silica with EtOAc - petrol (35:65). The protected aminomethylene ketone 30 was isolated as a yellow oil (54%). (viii) The aminomethylene ketone 30 (0.12 mmol) was deprotected and purified as described in Example ΙΠ (vi). Pure 31 (CH-694) was isolated as a white solid (41 mg). Hplc, linear gradient 20 —> 80% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 mins at 1.5 ml min1 indicated the presence of two epimers D-Arg (50%) at 11.2 min and L-Arg (50%) at 12.5 mins. After hydrolysis at 110°C/22 hrs with 6N HC1, amino acid analysis Phe, 0.91; Pro, 1.09.

All analogues in Table 4 were synthesised by the described method. The required amines were synthesised by standard synthetic methods such as reductive amination and the Curtius rearrangement.

EXAMPLE VI H-DPro-Phe-Arg-Gly-Pro-NHEt (see Scheme VI) DL (i) H2C(CO2Tce)2 (6.81 mmol) was treated with sodium hydride (5.67 mmol) in dry THF (30 cm3). After 45 mins the bromoketone 13 (4.52 mmol) was added at -5°C. After 2i hours 0.3 M KHSO4 was added, the crude product extracted with EtOAc and purified by flash chromatography on silica with EtOAc - petrol (2:8). The pure Boc-Arg(Z2)CH2CH(C02Tce)2 32 was isolated as a colourless oil (83%). (ii) Activated zinc was added to a solution of 32 (3.65 mmol) in glacial acetic acid. After 2i hours at room temperature the zinc was filtered off, the filtrate evaporated and the diacid 33 isolated. (iii) A solution of the diacid 33 in toluene was heated at reflux for 45 mins. The solvent was evaporated and the crude product purified by flash chromatography on silica with EtOAc - petrol - AcOH (60:39:1). The Boc-ArgiZ^ly-OH 34 was isolated as a colourless oil (70% from 32). (iv) Trichloroethanol (2.82 mmol), water soluble carbodiimide (2.81 mmol) and dimethylaminopyridine (0.117 mmol) were added to a solution of 34 (2.34 mmol) in CH2C12 (50 cm3) at 0°C. After 21 hours the reaction was worked up using standard procedures and the crude product purified by flash chromatography on silica with EtOAc - petrol (85:15). The trichloroethyl derivative 35 was isolated as a colourless oil (83%). (v) The Boc protecting group of 35 (1.85 mmol) was removed using sat. HCl/Dioxan and the resulting product acylated with Boc-Phe-OPfp (6.04 mmol) in CH2C12 in the presence of DIEA. After 2 hours the reaction was worked up using standard procedures and the crude product purified by flash chromatography on silica with EtOAc petrol (2:8). The pure product 36 was isolated as a colourless oil (85%). (vi) The Boc protecting group of 36 (1.58 mmol) was removed using sat. HCl/Dioxan and the resulting product acylated with Boc-DPro-OPfp (5.12 mmol) in CH2C12 in the presence of DIEA. After 2 hours the reaction was worked up using standard procedures and the crude product purified by flash chromatography on silica with EtOAc - petrol (35:65). The pure product 32 was isolated as a colourless oil (79%). (vii) Activated zinc dust was added to a solution of 37 (1.13 mmol) in glacial acetic acid. After 21 hours at room temperature the zinc was filtered off, the filtrate evaporated and the crude product purified by flash chromatography on silica with EtOAc - petrol - AcOH (70:29:1). The product 38 was isolated as a colourless oil (76%). (viii) The protected keto isostere 38 (0.26 mmol) was converted to its Pip ester by treatment with Pfp-OH (0.29 mmol) and water soluble carbodiimide (0.31 mmol) in CH2C12 (8 cm3) at 0°C for 21 hours. This Pfp ester was coupled at 0°C to H-Pro-NHEt. HCl salt (0.78 mmol) in the presence of DIEA. After 18 hours the reaction was worked up using standard procedures and the product purified by flash chromatography on silica with CHCl3-MeOH-AcOH (97:2:1). The product 39 was isolated as a colourless oil (91%). (ix) The protected keto isostere containing analogue 39 (0.23 mmol) was deprotected as described in Example ΠΙ (vi). Pure 40 (CH-595) was isolated as a white solid (40 mg). Hplc, linear gradient 10 —* 50% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 mins at 1.5 ml min'1 indicated the presence of two epimers D-Arg (46%) at 10.1 min and L-Arg (54%) at 11.7 min. After hydrolysis at 150°C/1.5 hrs with 6N HCl amino acid analysis Phe, 0.91; Pro, 1.09.

All analogues in Table 5 were synthesised by the described method.

EXAMPLE VII H-DPro-Phe-Arg-Chg-NH2 (see Scheme VII) (i) Boc-Phg-OH (19.9 mmol) was dissolved in AcOH/H2O (9:1, 100 cm3) and hydrogenated over Rh/C at 60 p.s.i. for 3 days. The catalyst was filtered off and the solvent removed to give Boc-Chg-OH 41 (100%). (ii) Water soluble carbodiimide (4.1 mmol) and HOBt (4.3 mmol) were added to a solution of 41 (3.9 mmol) in CH2C12/DMF (2:1, 60 cm3) at room temperature. After 30 mins 35% ammonia solution (0.8 cm3) was added. After a further 3 hours at room temperature the reaction was worked up using standard procedures and the product recrystallised from EtOH to give the pure amide 42 as a white solid (60%). (iii) The Boc group of 42 (0.77 mmol) was removed with sat. HCl/Dioxan to give the amide 43 as a white solid (100%). (iv) The protected tripeptide 27 (0.38 mmol) was dissolved in DMF (5 cm3). 43 (0.76 mmol), HOBt (0.76 mmol) water soluble carbodiimide (0.46 mmol), and N-methylmorpholine were added at 0°C. After 18 hours at room temperature the reaction was worked up using standard procedures and the product purified by flash chromatography on silica with CHCiyMeOH (99:1). The pure protected tetrapeptide 44 was isolated as a white solid (69%). (v) The protected tetrapeptide 44 (0.27 mmol) was deprotected and purified as described in Example ΙΠ (vi). Pure 45 (CH-640) was isolated as a white solid (58 mg). Hplc, linear gradient 10 —* 50% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 min at 1.5 ml min1, single peak detected at 14.2 min. After hydrolysis at 110°C/22 hrs with 6N HC1, amino acid analysis, Arg, 0.96; Phe, 1.00; Pro, 0.95.

All analogues in Table 6 were synthesised by the described method or by other standard peptide coupling methodology. (M. Bodansky & A. Bodansky, The Practice of Peptide Synthesis, Springer-Verlag, 1984) EXAMPLE VHI H-DPro-Phe-Arg-N[(CH2)5CH3](CH2)3Ch (see Scheme VIII) (i) The protected tripeptide 27 (0.32 mmol) was dissolved in DMF (5 cm3), HN[(CH2)5CH3](CH2)3Ch (0.96 mmol), HOBt (0.64 mmol), water soluble carbodiimide (0.38 mmol) and N-methylmorpholine were added at O°C. After 18 hours at room temperature the reaction was worked up using standard procedures and the product purified by flash chromatography on silica using EtOAc/Hexane (4:6). The amide 46 was isolated as a colourless oil (32%). (ii) The protected tripeptide amide 46 (0.1 mmol) was deprotected and purified as described in Example ΙΠ (vi). Pure 47 (CH-985) was isolated as a white solid (17 mg). Hplc, linear gradient 40 —* 90% 0.1% TFA/MeCN into 0.1% TFA/H2O over 25 min at 1.5 ml min'1, single peak detected at 10.7 min. After hydrolysis at 110°C for 22 hrs with 6N HC1, amino acid analysis Phe, 1.01; Pro, 0.99.

All analogues in Table 7 were synthesised by the described method. The required tripeptide presursors were synthesised in a similar manner to 27 or by standard peptide coupling methodology. (M. Bodansky & A. Bodansky, The Practice of Peptide Synthesis, Springer-Verlag, 1984.) Required amines were either commercially available or synthesised via the Curtius rearrangement. nBu-DPro-OH for 181 was synthesised by reductive amination.

Scheme 1 (Synthesis of compound 5) Z, (i) ‘BuOCOCl/NMM/THF i Boc-Arg-OH NaBH4/H2O Boc-Arg—OH 1 (ii) HCl/Dioxan Boc-Cha-ONSu/NMM CH2C12 z, I Z(NMe)DPhe-Cha-Arg £ OH 3 (iii) HCl/Dioxan ◄Z(NMe)DPhe-OH HOBt/wscd NMM/DMF Z, Boc-Cha-Arg - OH (iv) Dess Martin Periodinane CH2Cl2/AcOH Z2 (v) H2, Pd/C Z(NMe)DPhe-Cha-Arg-H Me-DPhe-Cha-Arg-H MeOH/H2O/AcOH ζ H-Lys-OMe . HCl Z Tcboc-LysOBCN 8a (iv) HCl/Dioxan MeOH/O°C H2O/4°C ▼ Z Tcboc-Lys^CO2Me 8b Z Boc-DPro-Phe-Lys°^CO2Me 10b (viii) LiOH/H2O THF f Z Boc-DPro-Phe-Lys^COoH 10c H-DPro-Phe-Lys-CONnBu2 Scheme Π (Synthesis of compound 11) (i) TcbocONSu Z -► Tcboc-Lys-OMe Et3N/CH2Cl2 , (ii) DIBAL/Toluene γ (iii) KCN HC1/H2O EtOAc Z ι Tcboc-Lys-H (v) Zn/AcOH Z H-Lys^COoMe (vi) Boc-Phe-ONSu CHC12/NMM f (vii) HCl/Dioxan -4- Boc-Phe-Lys^CO2Me Boc-DPro-ONSu _ NMM/CH2CI2 Ox) PfpOH/wscd/CH2Cl2 Z -► Boc-DPro-Phe-Lys^CONnBu2 nBu2NH/DIEA (xi) HCl/Dioxan H2,Pd/C AcOH/H2O lOd (x) Dess Martin Periodinane CHCl^AcOH Z - Boc-DPro-Phe-Lys-CONnBu2 lOe Boc-Arg-OH Scheme III (Synthesis of compound Γ7) (i) ’BuOCOCl/NMM/THF Zo I “ -► Boc-Arg-CHN2 (ii) CH2N2 p (ii) HBr/EtOAc THF Z2 Boc-Arg-S(CH2)4CH3 (iii) CH3(CH2)S'Na+ ◄DMF Boc-Arg-CH2Br (iv) HCl/Dioxan Boc-Phe-OPfp DIEA/CH2C12 t Z2 (v) HCl/Dioxan Boc-Phe-Arg-CH2S(CH2)4CH3 *Boc-DPro-OPfp DIEA/CH2C12 Z, ι ~ Boc-DPro-Phe-Arg-CH2S(CH2)4CH; (vi) HCl/Dioxan Ho Pd/C AcOH/H2O H-DPro-Phe-Arg-CH2S(CH2)4CIl3 Scheme IV (Synthesis of compound 23) Boc-Arg-CH2Br (i) CHF2(CF2)3CH2O'Na+ Z2 Boc-Arg-CH2OCH2(CF2)3CHF2 DMF (ii) NaBHyMeOH ?2 Boc-Phe-Arg—CH2OCH2(CF2)3CHF2 20 (iii) HCl/Dioxan Boc-Phe-OPfp DIEA/CH2C12 Boc-ArgQHCH2OCH2(CF2)3CHF2 (iv) HCl/Dioxan Boc-DPro-OPfp DIEA/CH2C12 Y Boc-DPro-Phe-Arg°!iCH2OCH2(CF2)3CHF2 (v) Dess Martin Periodinane CH2Cl2/AcOH γ Boc-DPro-Phe-Arg-CH2OCH2(CF2)3CHF2 (vi) HCl/Dioxan H2 Pd/C AcOH/H2O Y H-DPro-Phe-Arg-CH2OCH2(CF2)3CHF2 Boc-Arg-OH Scheme V (Synthesis of compound 31) (i) Tce-OH/wscd DMAP/CHoCU Boc-Arg-OTce (ii) HCl/Dioxan Boc-Phe-ONSu CH2C12/NMM Z, i “ Boc-DPro-Phe-Arg-OTce (iii) HCl/Dioxan Z7 Boc-Phe-Arg-OTce (iv) Zn/AcOH Zo i Boc-DPro-Phe-Arg-OTce Zo Boc-DPro-Phe-Arg-CH2N[(CH2)5CH3]2 Boc-DPro-ONSu CHoCU/NMM (v) 'BuOCOCl/NMM/THF CH2N2/Et2O Boc-DPro-Phe-Arg-CHN 7 (vi) HBr/EtOAc THF (vii) HN[(CH2)5CH3]2 NaHCO3/THF Z, Boc-DPro-Phe-Arg-CH2Br HCl/Dioxan H2, Pd/C, AcOH, H2O H-DPro-Phe-Arg-CH2N[(CH2)5CH3]2 (viii) Scheme VI (Synthesis of compound 40) (i) Na+-CH(CO2Tce)2 Boc-Arg-CH2Br Boc-Arg-CH2CH(CO2Tce)2 (ii) Zn/AcOH Boc-Arg-Gly-OH (iii) Toluene / Δ -◄Boc-Arg-CH2CH(C02H)2 (iv) Tce-OH/wscd DMAP/CH2C12 (v) HCl/Dioxan Boc-Arg-Gly-OTce Boc-Phe-OPfp DIEA/CH2C12 Boc-Phe-Argi^Gly-OTce (vi) HCl/Dioxan Boc-DPro-OPfp CH2C12/DIEA Boc-DPro-Phe-Arg^Gly-OH (vii) Zn/AcOH Boc-DPro-Phe-Arg^Gly-OTce PfpOH/wscd/CH2Cl2 HPro-NHEt/DIEA (ix) HCl/Dioxan Boc-DPro-Phe-Arg^Gly-Pro-NHEt ► H-DPro-Phe-Arg^Gly-Pro-NHI H2, Pd/C AcOH/H2O (viii) Scheme VII (Synthesis of compound 45) (i) H2,Rh/C Boc-Phg-OH AcOH/H2O/60 psi Boc-Chg-OH (ii) HOBt/wscd DMF/CH2C12 nh3 (iii) HCl/Dioxan H-Chg-NH2 HCl ◄43 y Boc-Chg-NH2 (iv) Boc-DPro-Phe-Arg-OH 27 HOBt/wscd/DMF Boc-DPro-Phe-Arg-Chg-NH2 ► H-DPro-Phe-Arg-Chg-NH2 H2, Pd/C AcOH/H2O ?2 (v) HCl/Dioxan Scheme VIII (Synthesis of compound 47) ?2 Boc-DPro-Phe-Arg-OH HN[(CH2)5CH3] (CH2)£h -► Boc-DPro-Phe-Arg-N[(CH2)5CH3](CH2)3Ch HOBt/wscd/DMF (ii) HCl/Dioxan H2 Pd/C AcOH/H2O H-DPro-Phe-Arg-N[(CH2)5CH3](CH2)3Ch v Scheme IX (Synthesis of compound 48) Zz Boc-Arg^OH Dess-Martin Periodinane CH2C12/AcOH t Z, ι ~ 3oc-Arg-H CF3CF0CF2I Zo -► Boc-Arg—CF2CF2CF3 Zn/THF/Ultrasouna HCl/Dioxan Boc-Phe-ONSu NMM/CH2C12 Z2 HCl/Dioxan Soc-DPro-Phe-Arg<5iiCF2CF2CF3 4Boc-DPro-ONSu NMM/CH2C12 Dess Martin Periodinane CH2Cl2/AcOH I HCl/Dioxan 12 Boc-DPro-Phe-Arg-CF2CF2CF3 -► Z2 Boc-Phe-Arg—CF2CF2CF3 H-DPro-Phe-Arg-CF2CF2CF3 H2, Pd/C AcOH/H2O Scheme X (Synthesis of compound 49) Boc-DPro-Phe-Arg-CH2Br Zn/AcOH -► Boc-DPro-Phe-Arg-CH3 HCl/Dioxan H2, Pd/C AcOH/H2O H-DPro-Phe-Arg-CH3 Scheme XI (Synthesis of compound 50) Z I Boc-Arg-CH2Br OMe DMF Boc-Arg-CHoO OMe (i) NaBH4/MeOH (ii) TBDMS Triflate Lutidene/CH2C12 i 2 Cerric ammonium nitrate 3oc-ArgGTBPMSCH2OH ◄i MeCN/H2O I O°C < i) Dess-Martin Periodinane CH2C12/AcOH (ii) Br2/MeOH/H2O/NaHCO3 Z Boc-ArgOTBD?0sCH2O -OMe 3oc-Arg^I5£^CO2Me HCl/Dioxan Boc-Cha-ONSu CH2C12/NMM z Boc-Cha-Arg°^-DMSCQ2Me HCl/Dioxan Boc-DPro-ONSu NMM/CH2C12 z B oc - DPro-Cha-ArgT^MSCO2H NaOH/MeOH ◄O°C z Boc-DPro-Cha-Arg2™2MSCO2xMe (i) PfpOH/wscd/CH2Cl2 (ii) nBu2NH B oc - DPro-Cha-Arg^^^CONnBu2 (i) TBAF/THF -> (ii) Dess-Martin Periodinane CH2Cl2/AcOH Z i Boc-DPro-Cha-Arg-CONnBu2 (i) HCl/Dioxan (ii) H2Pd/C MeOH/H2O HCl H-DPro-Cha-Arg-CO2NnBu2 Z Boc-Orn-OH Bzl 3oc-Orn-OH Scheme ΧΠ (Synthesis of compound 53) 'BuOCOCl/NMM/THF Z -> Boc-Om^OH NaBH4/H2O H2Pd/C AcOH/H2O f PhCHO/CH2Cl2/Et3N/MgSO4 Boc-Om^OH ◄NaBH4/MeOH ZONSu Et3N/CH2Cl2 ▼ Bzl, Z Boc-Om-OH Dess-Martin Periodinane CH2Cl2/AcOH H2C(CO2Bzl)2 NaH/THF Bzl, Z Boc-Orn-H nHexCH(CO->Bzl)2 Ήβχ20(0Ο2Η)2 Δ/Toluene HexI NaH/THF nHexI/60°C J H2Pd/C —- nHexoC(CO7Bzll2 MeOH nHex2CHCO2H RedAl/Toluene -> nHex2CHCH2OH MsCl/Et3N/CH2Cl2nHex2CHCH2Br LiBr/Acetone «<nHex2CHCH2OMs (cont.) Scheme ΧΠ (cont.) nHex2CHCH2Br Mg/THF -> Bzl, Z Boc-Orn^CH.CiTHex, HCl/Dioxan Boc-Phe-ONSu CH2C12/NMM Bzl, Z 3oc-£)Pro-rhe-Crnf— CHiCHHlex-, HCl/Dioxan MBoc-DPro-ONS u/NMM CHoCH * Bzl. Z Boc-Phe-OrnQHCH2CHRHex2 H2 Pd/C AcOH/H2O ▼ 3oc-DPro-Phe-Om—CH2CHnHex2 ch3s-c ^NZ ^NHZ > EtOH/Δ Boc2-DPro-Phe-Arg—CHoCI^Hex Dess Martin Periodinane CH2C12AcOH v H - DPro-P he - Arg-CH2CHnHe x 2 HCl/Dioxan ◄Boc-DPro-Phe-Arg-CHnCrPHex^ H2Pd/C AcOH/H2O Scheme XIII (Synthesis of compound 54) ?2 Boc-DPro-Phe-Arg-CH2Br PhCOCO2H/KF -> DMF Boc-DPro-Phe-Arg-CH2OCOCOPh KHCO^O/THF ?2 CH3(CH2)5I/Ag2O Boc-DPro-Phe-Arg-CH2O(CH2)5CH3 ◄CH2C12 Boc-DPro-Phe-Arg-CH2OH HCl/Dioxan H2, Pd/C AcOH/H2O H-DPro-Phe-Arg-CH2O(CH2)5CH3 Scheme XIV (Synthesis of compound 55) ?2 Boc-DPro-Phe-Arg-CH2Br PhOH/KF ?2 -► Boc-DPro-Phe-Arg-CH2OPh DMF HCl/Dioxan H2Pd/C AcOH/H2O H-DPro-Phe-Arg-CH2OPh ABBREVIATIONS USED Abn 3-Azabicyclo[3.2.2l-nonane Ac Acetyl AcOH Acetic acid Ada Adamantylalanine Aha 2-Aminohexanoic acid (Norleucine) Boc tert-Butyloxycarbonyl Bu Butyl Ch Cyclohexyl Cha Cyclohexylalanine Chg Cyclohexylglycine Cpr Cyclopropyl DIEA Diisopropylethylamine DMAP 4-Dimethylamino-pyridine DMF Dimethylformamide EtOAc Ethyl acetate FAB Fast Atom Bombardment 4-Fph 4-Fluorophenylalanine Hch Homocyclohexylalanine HOBt 1 -Hydroxybenzotriazole hplc high performance liquid chromatography Hyp 4-Hydroxyproline 'Hyp trans-4-Hydroxyproline κ Me MeCN MeOH mplc Nal NMM Npg Oc OH ONSu Petrol Pfp Phe-4NO2 Phg Pic Pip Py R Sar TBAF TBDMS Tcboc Tee keto isostere -COCH2Methyl Acetonitrile Methanol medium pressure (preparative) liquid chromatography Naphthylalanine N-Methylmorpholine Neopentylglycine Octyl Hydroxy isostere -CHOHhydroxysuccinimide Petroleum ether 60 - 80°C Pentafluorophenyl 4-Nitrophenylalanine Phenylglycine Pipecolinic acid Piperidyl Pyridine Reduced isostere -CH2Sarcosine (N-methylglycine) Tetrabutylammonium fluoride tert-Butyldimethylsilyl (1 -Dimethyl-1 -trichloromethyl)ethoxy carbonyl 2,2,2-Trichloroethyl Tha 3,3,5-Trimethylhexahydroazepyl THF Tetrahydrofuran Thi Thienylalanine Tic 1,2,3,4-Tetrahydroisoquinoline-3-carboxylic acid tic thin layer chromatography wscd water soluble carbodiimide z Benzyloxycarbonyl Nor Norarginine BIOLOGICAL ACTIVITY; MEDICAL USE Compounds were tested in vitro for the following activities using standard procedures: (a) Inhibition of human tissue kallikrein, plasma kallikrein and mast cell tryptase hydrolysing the chromogenic substrates S-2266, S-2302 and S-2266 respectively (method is adapted from that of Johansen, H.T. , et al., Int. J. Tiss. Reac., 1986, 8, 185-192). A series of measurements were carried out using a number of different inhibitor concentrations and at least two different substrate concentrations. The inhibitory constant Ki was determined graphically, using a Dixon plot (M. Dixon, Biochem. J., 1953, 55, 170). (b) Inhibition of kinin release from low and high molecular weight kininogens by tissue and plasma kallikrein respectively. A series of measurements were carried out using two substrate concentrations. The activity is calculated as the amount of kinen released per minute, this being determined by radioimmunoassay using polyclonal antibodies. The inhibitory constant Ki was determined graphically using a Dixon plot.

All the examples in Tables 1-9 have Ki values in the __ c _ Q range 10 3 - 10 M against one or all of the enzymes m the chromogenic assay.

In vivo activity has been tested in well-established pharmacology models of asthma based on the sensitised guinea pig. A selection of these inhibitors representing the different chemical types proved to be highly effective in blocking both the acute phase response and the late phase reaction, their efficacy being comparable or superior to those of the topical steroids and S2-agonist currently used in asthma therapy.

When the compounds of the present invention are used as a medicine, there are no critical limitations to the administration methods. The present enzyme inhibitor can be formulated by any conventional method in pharmaceutics. For example, the present enzyme inhibitor may be applied in any conventional manner including intravenous injection, intramuscular injection, instillation, oral administration, respiratory inhalation, instillation, rhinenchysis, and external skin treatment. Although there are no critical limitations to the administration dosage, the suitable dosage is 1 to 1000 mg/day/person.

Claims (23)

1. Kininogenase inhibitors, optimally not exceeding the size of a hexapeptide, represented by:- wherein A and B = amino acyl (including amino acyl analogue) the same or different forming a dipeptide group the amino acid of A carrying a terminal group and being any amino or imino-acid residue (but preferably of D-configuration) and of B being a lipophilic amino-acid residue of D- or Lconfiguration but not proline or a proline analogue, or a conformational analogue of said dipeptide group wherein the peptide link is replaced by -CH 2 -NH- ('reduced')/ -CH(OH)-CH 2 ('hydroxy'), -CO-CH 2 - ('keto'), -CH 2 -CH 2 ('hydrocarbon') or other conformational mimic of the peptide bond and in:IE 913120 the side chain R 1 is that of a basic amino acid or amino acid analogue (preferably of Lconfiguration) and R is H or lower alkyl (C^ C 4 ) or C a or the peptide link comprising -N(R)- is replaced leading to a conformational mimic as above Y = a binding enhancing or carbonyl activating group preferably selected from H (when A or B must be cyclohexylalanine, preferably D if at A or L if at B) or alkyl (C-^ - C 20 ) or fluoroalkyl (C 2 - C 12 ); substituted oxymethylene; thiomethylene; sulphoxymethylene; sulphonylmethylene; aminomethylene; hydrazino-methylene; -CH 2 -Het (where Het = a substituted or unsubstituted heterocycle); substituted amino (but when the resulting compound is a secondary alkylamide B must not be phenylalanine); an amino-acid group or its ester or amide; a carboxylic secondary amide or primary amide, when B must be cyclohexylalanine or adamantylalanine or other bulky lipophilic, non-aromatic amino-acid (not Ala Leu lie Val Nva Met Nle Phe Tyr Trp Nal (1)); tertiary-carboxamide; carboxy-alkyl group or its ester or amide or amino acyl derivative.

2. Compounds according to claim 1 wherein A is selected from imino-acids, (e.g. D-proline or an analogue of proline e.g. pipecolinic acid, azetidine carboxylic acid); lipophilic amino acids (e.g. DPhe, DCha, DChg); strongly basic amino acids (e.g. D-Arg or a homologue or analogue of Arg, e.g. amidino- or guanidinophenylalanine); or N-alkyl or C a -alkyl (including benzyl) derivatives thereof.

3. Compounds according to claim 1 or 2 wherein B is selected from L-Phe, L-Cha, L-ceNal, L-Tal, L-(4F)Phe L-(NMe)Phe or other substituted phenylalanines; or N-alkyl or C a -alkyl (including benzyl) derivatives thereof.

4. Compounds according to claim 1, 2, or 3 wherein R 1 is selected from 3-guanidinopropyl or other guanidinoalkyl group, (or an amidinoalkyl or aminoalkyl group), also para- or meta substituted guanidino or amidino-benzyl or protected forms of the above; optionally basic nitrogens are alkylated (Me, Et or other).

5. Compounds according to any preceding claim wherein subject to the provisos in regard to the nature of Y expressed in claim 1, selection for Y is from:Y = H or alkyl including fluoroalkyl Y = -ch 2 q where Q = -OR 2 or -SR 2 or -SOR 2 or -SO 2 R 2 or -NHR 2 or wherein R 2 , R 4 and R 5 are as below Y = -ch 9 chr 6 con or -CH 2 CHR 6 CO-d) wherein R 4 , R^ and R 6 are as below Y = amino acyl or a group forming a substituted amide or hydrazide Y = a group forming an α-keto amide - COR 9 or -CO-D^ or and in which further :R 2 = alkyl or substituted alkyl including aryl or aryl alkyl or -CH 2 R 3 where R 3 = fluoroalkyl R 4 and R 5 the same or different but not both hydrogen = H or C 1 -C 20 alkyl (which may be further substituted), acyl or alkyl sulphonyl is a heterocyclic ring (D = nitrogen or carbon in Group IV and N in Groups VI and X) optionally unsaturated and optionally with further hetero atoms and substituents R 6 hydrogen, alkyl, hydroxyalkyl, aminoalkyl alkylaminocarbonyl -NH 2 as such or alkylated, or amino acyl.

6. Compounds according to any claim 1 to 4 wherein subject to the provisos in regard to the nature of Y expressed in claim 1, selection for Y is from:Group I Y = H; alkyl including branched alkyl (C^-C 2 q); aryl alkyl; or cycloalkyl ( c i“C 20 ); perfluoroalkyl or partially fluorinated alkyl (C 2 -C 12 ); [e.g. Y = Me; -CH(CH 2 CH 2 CH 2 CH 3 ) 2 ; -CH(CH 2 CH 2 CH 2 CH 3 )CH 2 -cyclohexyl; -CH 2 CF 2 CF 2 CF 3 ; -CF 2 CH 2 CH 2 CH 3 J . Group II Y = -CH 2 QR 2 where Q = O, S, SO, SO2, NH and where R 2 = Alkyl, branched alkyl or acyl (C-L-C- L2 ); °r cycloalkyl (C 1 -C 20 ); or aryl or aryl alkyl; or -CH 2 -R 3 where R 3 = perfluoroalkyl or partially fluorinated alkyl, branched or not Group III V = -CH 2 n^ R 4 , R 5 the same or different = alkyl, branched alkyl, cycloalkyl, acyl, alkylsulphonyl, carboxyalkyl (the carboxyl group may be further derivatized to form an ester or amide with an amino-acid or dipeptide), carbamoyl, sulphamoyl, N-dialkylamino-, arylalkyl, haloalkyl including fluoroalkyl, cyanoalkyl, alkoxyalkyl, hydroxyalkyl, mercaptoalkyl, aminoalkyl and derivatives thereof e.g. esters, amides and thioesters; or one of R 4 or R 5 = hydrogen Group IV Y = -ch 2 - d) where D = nitrogen or carbon and is a saturated or unsaturated heterocyclic ring or a bicyclic ring system, each is 5 - 8 membered, where there may be other heteroatoms (N, S, 0) and carbons or nitrogens may optionally be substituted by alkyl, branched alkyl, cycloalkyl, carboxyalkyl, carboxy (attached to carbon), amino, alkoxy, alkoxymethyl or (carbon) as carbonyl or other groups beneficial for interaction with the enzyme. Group v Y = -CH 2 CH(R 6 )CONR 4 R 5 a c R , R as defined in Group III. R 6 = hydrogen lower alkyl, branched alkyl, cycloalkyl, hydroxyalkyl, amino-alkyl, alkylaminocarbonyl. group ,VI Y = -CH 2 CH(R 6 )00^) R 6 as defined in Group V and - D) as defined in Group IV (but with D = N) Group VII Y = an amino-acid residue or any amide (secondary or tertiary) or ester of that residue, L or D configuration. Preferred residues are of lipophilic amino-acids e.g. norleucine, cyclohexylalanine, homocyclohexylalanine,cyclohexylglycine, tert butylglycine. Group VIII R 7 Y = - N-R 8 7. Ft R = H (when however B is not phenylalanine unless R is carboxylalkyl or derivatized carboxylalkyl) ; or alkyl, branched alkyl (Ο τ - C 12 ), cycloalkyl (¢^02,5) carboxyalkyl or bis ( carboxyl ) alkyl , which may be derivatized at the carboxyl group to form an amide e.g. with an amino-acid (preferred is arginine) or a substituted amine; N'-dialkylamino; N'-alkylamino-; ft 7 . R = R the same or different but excluding H. Group IX Y = -CO-R 9 but only if B is a bulky non-aromatic lipophilic amino acid or its N? alkyl (C^ - C 4 ) derivative (e.g. cyclohexylalanine but excluding Ala, Leu, lie, Val, Nva, Met, Nle, Phe, Tyr, Trp, Nal(l) and their N-methyl derivatives) where R 9 = nh 2 , N'-alkylamino (where the alkyl groups include branched and/or cycloalkyl); an amino-acid residue. GCQUP X as defined in Group IV (but D = N) Group XI Y = -CO-NR 4 R 5 R 4 ,R 5 as defined in Group III, but not H.

7. Any one of the compounds specifically listed in Tables 1 to 9 herein.

8. A method of treatment (including prophylactic treatment) of an inflammatory or other condition as set out in the indications (1) to (6) herein, particularly an allergic inflammatory condition, wherein an effective amount of a peptide or peptide-analogue kininogenase inhibitor is administered topically or systemically to a patient suffering from or at risk of the condition, the peptide or peptide analogue used being optimally of hexapeptide or smaller size.

9. A method of treatment of the allergic inflammatory phase of asthma, wherein an effective amount of a kininogenase inhibitor e.g. a mast cell tryptase inhibitor is administered topically or systemically to a patient suffering from or at risk of the condition.

10. A method of preparation of a medicament for the topical or systemic treatment (including prophylactic treatment) of conditions as in claim 8 particularly for allergic inflammatory conditions and especially for asthma as in claim 9, wherein a kininogenase inhibitor is associated in effective amounts with a pharmaceutically acceptable diluent or carrier to constitute said medicament.

11. A method of treatment or of preparation of a medicament as above wherein the inhibitor is a compound as claimed in any of claims 1 to 7.

12. A process for the preparation of a kininogenase inhibitor of the general formula given and defined in claim 1, substantially as hereinbefore described and exemplified.

13. A kininogenase inhibitor of the general formula given and defined in claim 1, whenever prepared by a process claimed in claim 12.

14. A compound according to any one of claims 1-7 or 13 for use in therapy or prophylaxis.

15. A compound according to any one of claims 1-7 or 13 for use in treatment and/or prophylaxis in accordance with any one of indications (1) to (6) hereinbefore specified.

16. A compound according to any one of claims 1-7 or 13 for use in the treatment of the allergic inflammatory phase of asthma.

17. Use of a peptide or peptide-analogue kininogenase inhibitor in the manufacture of a medicament for use in treatment and/or prophylaxis in accordance with any of indications (1) to (6) hereinbefore specified.

18. Use of a peptide or peptide-analogue kininogenase inhibitor in the manufacture of a medicament for use in the treatment of the allergic inflammatory phase of asthma.

19. Use according to claim 17 or 18 wherein the inhibitor is a compound according to any one of claims 1-7 or 13.

20. Use according to any one of claims 17-19, wherein the medicament is administered by the systemic route.

21. Use according to any one of claims 17-19, wherein the medicament is applied topically.

22. Use according to claim 15 or 16, substantially as hereinbefore described.

23. Use according to any one of claims 17-21, substantially as hereinbefore described.