US 7,122,628 B2Granted

Process for the synthesis of a peptide having a Trp residue

AssigneeIpsen Manufacturing Ireland Limited

InventorSteven Allen Jackson

Life of this patent

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Abstract

A process for the solid phase synthesis of a peptide having at least one thyptophan residue, wherein said method comprises temporarily protecting the indole ring of said tryptophan residue with a side chain protecting group which is labile to a base wherein said protecting group is removed during cleavage of said peptide from the solid support.

Claims12

Dependent claims

A process for making a peptide of the formula (I),

ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2, (I)
wherein said process comprises:
(a) temporarily protecting the indole-NH group on the side chain of any tryptophan residue with a side chain protecting group;
(b) temporarily protecting the side chain of the histidine residue with a side chain protecting group;
(c) attaching a cesium salt of Boc-Gly onto a chloromethylated polystyrene resin to yield Boc-Gly resin;
(d) deblocking Boc-Gly-resin by mixing the Boc-Gly-resin with a mixture of a Boc-deblocking organic acid to yield an organic acid salt of H2N-Gly-resin;
(e) neutralizing the organic acid salt of H2N-Gly-resin with a base to yield H2N-Gly-resin;
(f) successively coupling H2N-Gly-resin with a Boc-α-amine protected amino acid, said protecting amino acid corresponding to ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2 in the order shown from the C-terminal to the N-terminal, wherein said coupling comprises:
(i) reacting H2N-Gly-resin with the Boc-α-amine protected amino acid in the presence of a peptide coupling agent to yield a Boc-blocked coupled product;
(ii) deblocking the Boc group from the Boc-blocked coupled product by mixing the Boc-blocked coupled product with a Boc-deblocking organic acid to yield a coupled product;
(iii) reacting the coupled product with a next Boc-α-amine protected amino acid in the presence of a peptide coupling agent to yield a Boc-blocked coupled product;
(iv) deblocking the Boc group from the Boc-blocked coupled product by mixing the Boc-blocked coupled product with a Boc-deblocking organic acid to yield a next coupled product;
(v) repeating steps (d)(iii) and (d)(iv) until the N-terminal amino acid of the peptide of formula (I) has been coupled and the Boc group of the N-terminal amino acid has been deblocked to yield a protected completed peptide-resin;
(vi) removing said side chain protecting group on the histidine residue;
(g) deprotecting the protected indole-NH group on the side chains of the tryptophan residues and cleaving the completed peptide-resin to yield ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2, wherein said deprotecting and cleaving comprises:
(i) making a solution of the protected completed peptide-resin in an alcohol/inert polar aprotic solvent mixture;
(ii) cooling the solution to about 0° C. to about 10° C.;
(iii) bubbling ammonia gas slowly and maintaining cooling until the solution is well saturated with ammonia to yield a saturated solution;
(iv) mixing the saturated solution without cooling for about 15–36 hours until <95% of free methyl ester is converted to the corresponding amide;
and
(h) isolating ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2 from said solution.

18 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/451,486Filed 19 Dec 2001
Priority: IE 2000/107922 Dec 2000
Published: US 2004/0077827 A122 Apr 2004
Granted: 17 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

C07K 1/068
Using protecting groups: for heterocyclic side chains
C07K 7/23
Linear peptides containing only normal peptide links: luteinising hormone-releasing hormone [LHRH]; Related peptides
Y02P 20/55
Improvements relating to the production of bulk chemicals: design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups
C07K
Peptides

Family

US 2004/0077827 A1Pre-grant publication · published 22 Apr 2004
US 7,122,628 B2This patent

From the US filing history. Foreign family members aren’t listed.

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Abstract

A process for making a peptide of the formula (I),

ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2, (I)
wherein said process comprises:
(a) temporarily protecting the indole-NH group on the side chain of any tryptophan residue with a side chain protecting group;
(b) temporarily protecting the side chain of the histidine residue with a side chain protecting group;
(c) attaching a cesium salt of Boc-Gly onto a chloromethylated polystyrene resin to yield Boc-Gly resin;
(d) deblocking Boc-Gly-resin by mixing the Boc-Gly-resin with a mixture of a Boc-deblocking organic acid to yield an organic acid salt of H2N-Gly-resin;
(e) neutralizing the organic acid salt of H2N-Gly-resin with a base to yield H2N-Gly-resin;
(f) successively coupling H2N-Gly-resin with a Boc-α-amine protected amino acid, said protecting amino acid corresponding to ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2 in the order shown from the C-terminal to the N-terminal, wherein said coupling comprises:
(i) reacting H2N-Gly-resin with the Boc-α-amine protected amino acid in the presence of a peptide coupling agent to yield a Boc-blocked coupled product;
(ii) deblocking the Boc group from the Boc-blocked coupled product by mixing the Boc-blocked coupled product with a Boc-deblocking organic acid to yield a coupled product;
(iii) reacting the coupled product with a next Boc-α-amine protected amino acid in the presence of a peptide coupling agent to yield a Boc-blocked coupled product;
(iv) deblocking the Boc group from the Boc-blocked coupled product by mixing the Boc-blocked coupled product with a Boc-deblocking organic acid to yield a next coupled product;
(v) repeating steps (d)(iii) and (d)(iv) until the N-terminal amino acid of the peptide of formula (I) has been coupled and the Boc group of the N-terminal amino acid has been deblocked to yield a protected completed peptide-resin;
(vi) removing said side chain protecting group on the histidine residue;
(g) deprotecting the protected indole-NH group on the side chains of the tryptophan residues and cleaving the completed peptide-resin to yield ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2, wherein said deprotecting and cleaving comprises:
(i) making a solution of the protected completed peptide-resin in an alcohol/inert polar aprotic solvent mixture;
(ii) cooling the solution to about 0° C. to about 10° C.;
(iii) bubbling ammonia gas slowly and maintaining cooling until the solution is well saturated with ammonia to yield a saturated solution;
(iv) mixing the saturated solution without cooling for about 15–36 hours until <95% of free methyl ester is converted to the corresponding amide;
and
(h) isolating ρGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2 from said solution.

18 more elements

Facts

Application

10/451,486Filed 19 Dec 2001

Priority

IE 2000/107922 Dec 2000

Published

US 2004/0077827 A122 Apr 2004

Granted

17 Oct 2006

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

C07K 1/068
Using protecting groups: for heterocyclic side chains
C07K 7/23
Linear peptides containing only normal peptide links: luteinising hormone-releasing hormone [LHRH]; Related peptides
Y02P 20/55
Improvements relating to the production of bulk chemicals: design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups
C07K
Peptides