Patent GB-1530182-A (GB)
Title: Peptides
IPC: C07K14/655
Filed: 1976-03-18
Abstract: 1530182 Polypeptides AMERICAN HOME PRODUCTS CORP 18 March 1976 [21 March 1975 10 Dec 1975] 10900/76 Heading C3H Peptides of Formula (I)  wherein n is an integer of 1 to 5; Trp represents D- or L-tryptophyl and other amino acids are of the L-configuration; and the non-toxic acid addition salts thereof. and the non-toxic acid addition salts thereof; wherein Trp represents either D- or L-tryptophyl, and all other amino acids are in the L- configuration; n is an integer of 1 to 5; R<SP>12</SP> is hydrogen or a protecting group for the #-amino group of lysine; R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP> are independently hydrogen or a protecting group for the alcoholic hydroxyl group of threonine and serine; R<SP>11</SP> is hydrogen or an α-carboxyl protecting group; R<SP>10</SP> is hydrogen or a protecting group for the amino function; with the proviso that at least one of R<SP>12</SP>, R<SP>3</SP>, R<SP>4</SP>, R<SP>6</SP>, R<SP>10</SP> and R<SP>11</SP> is other than hydrogen. Peptides of Formulae (III) or (J) wherein Trp represents D or L-tryptophyl and other chiral amino acids are of the L-configuration; R<SP>1</SP>, R<SP>2</SP> are the same or different and represent a protecting group for the #-amino group of lysine; R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP> independently are hydrogen or a protecting group for the hydroxyl group of threonine and serine; R<SP>9</SP>, R<SP>13</SP> are α- carboxyl protecting groups; R<SP>8</SP> is hydrogen or a side chain carboxyl protecting group which is removable under conditions that will not remove the R<SP>9</SP> carboxyl protecting group; R<SP>7</SP> is an α-amino protecting group which differs from said R<SP>1</SP>, R<SP>2</SP> groups in that it is cleavable under conditions which will not cleave said R<SP>1</SP> and R<SP>2</SP> protecting groups. Peptides of the Formula (II) R-Lys(R<SP>1</SP>)-Asn- Phe - Phe - Trp - Lys(R<SP>2</SP>) - Thr(R<SP>3</SP>) - Phe - Thr- (R<SP>4</SP>) - Ser(R<SP>5</SP>) - R<SP>6</SP> wherein Trp represents either D- or L-tryptophyl and other chiral amino acids are of the L-configuration; R is an α-amino protecting group that is cleaveable under conditions that will not cleave the R<SP>1</SP> and R<SP>2</SP> protecting groups; R<SP>1</SP> and R<SP>2</SP> are protecting groups for the #-amino group of lysine; R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP> independently are hydrogen or protecting groups for the alcoholic hydroxyl group of threonine and serine; R<SP>6</SP> is selected from OH, NHNH 2 , N 3 , OCH 3  and R<SP>1</SP> R<SP>2</SP>, R<SP>12</SP> are preferably selected from benzyloxycarbonyl, tosyl, t-amyloxycarbonyl, t-butyloxycarbonyl, diisopropylmethoxycarbonyl, substituted benzyloxycarbonyl wherein said substituted is selected from halo and nitro; R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP> are preferably selected from acetyl, benzoyl, t-butyl, trityl, benzyl, 2,6-dichlorobenzyl, benzyloxycarbonyl; R<SP>7</SP> is preferably t-butyloxycarbonyl; R<SP>9</SP>, R<SP>11</SP>, R<SP>13</SP> are preferably benzyl, phenacyl, phthalimidomethyl, benzhydryl, 1,1,1-trichloroethyl, 4-picolyl, α-methylthioacetyl, 4-(methylthio)-phenyl, substituted benzyl wherein said substituent is selected from at least one of nitro, methyl and methoxy; R is preferably selected from formyl, trifluoroacetyl, phthalyl, p-toluenesulphonyl, benzenesulphonyl, p-nitrophenylsulphenyl, tritylsulphenyl, O-nitrophenoxyacetyl, γ-chlorobutyryl, benzyloxycarbonyl, substituted benzyloxycarbonyl, benzhydrylcarbonyl, 1- (p - diphenylyl) - 1 - methylethoxycarbonyl, t-butyloxycarbonyl, α,α- dimethyl-3,5-dimethoxybenzyloxycarbonyl, diisopropylmethoxycarbonyl, isopropyloxycarbonyl, ethoxycarbonyl, alloxycarbonyl, cyclopentyloxycarbonyl, adamantyloxycarbonyl, cyclohexyloxycarbonyl, phenylthiocarbonyl, triphenylmethyl, benzyl, trimethylsilane. In the examples, wherein Trp is either D- or L-tryptophyl, the cesium salt of Boc-Ser (Bzl)- OH is reacted with chloromethylated polystyrene resin followed by sequential coupling of Boc-Thr (Bzl)-OH, Boc-Phe-OH, Boc-Thr- (Bzl)-OH, Boc-Lys-(ClCBz)-OH, Boc-Trp-OH, Boc-Phe-OH, Boc-Phe-OH, Boc-Asn-ONP, Boc-Lys-(ClCBz)-OH, with N-deprotection after each coupling to yield Boc-Lys-(ClCBz)- Asn - Phe - Phe - Trp - Lys - (CICBz) - Thr - (Bzl) - Phe - Thr - (Bzl) - Ser(Bzl) - O - Resin which, on treatment with hydrazine, yields Boc - Lys - (ClCBz) - Asn - Phe - Phe - Trp - Lys - (ClCBz) - Thr(Bzl) - Phe - Thr(Bzl) - Ser - (Bzl) - NHNH 2 , which, on reaction with H-Glu- (OBu')-OBzl yields Boc - Lys - (ClCBz) - Asn - Phe - Phe - Trp - Lys(ClCBz) - Thr(Bzl) - Phe - Thr(Bzl) - Ser(Bzl) - Glu(OBu<SP>t</SP>) - OBzl which is treated with trifluoroacetic acid to yield H - Lys(ClCBz) - Asn - Phe - Phe - Trp - Lys - (ClCBz) - Thr(Bzl) - Phe - Thr(Bzl) - Scr - (Bzl) - Glu - OBzl which is cyclized with 1 - hydroxybenzotriazole/dicyclohexylcarbodiimide to yield ClCBz - Lys(-) - Asn - Phe - Phe - Trp - Lys(ClCBz) - Thy(Bzl) - Phe - Thr(Bzl) - Ser(Bzl) - Glu(-) - OBzl - (cyclo 1 - α - lysyl to γ-glutamyl) which, on treatment with either (i) hydrogenation over palladium/carbon (LTrp) or (ii) hydrogen fluoride/anisole (D-Trp) yields Lys(-) - Asn - Phe - Phe - Trp - Lys - Thr - Phe - Thr - Ser - Glu(-) - OH(cyclo - 1-α-lysyl to γ-glutamyl). Pharmaceutical compositions comprise peptides I or a non-toxic acid addition salt thereof (preferably the hydrochloride, hydrobromide, sulphate, phosphates maleate, citrate, acetate, benzoate, succinate, malate or ascorbate), together with a pharmaceutically-acceptable carrier.