Patent ID: 7884182

Claim:
A composition of matter comprising an N-terminal heterocyclic-protected oligopeptide thioester defined by the following formula: wherein: each of Xaa 1 to Xaa n , is independently a protected or unprotected amino acid; n is an integer from 2 to 120; R 1 is hydrogen; R 2 is hydrogen, unsubstituted alkyl having from 1 to 3 carbon atoms or an electron withdrawing-substituted alkyl having from 1 to 3 carbon atoms, said electron withdrawing substituent-selected from the group consisting of: halo, cyano, nitro-substituted alkyl having from 1 to 3 carbon atoms, carbonyl, carboxy, carboxyester, carboxyamide, amidocarboxy, amidocarbonyl, sulfoxy, sulfone and quartenary ammonium salts, wherein R 2 may optionally be attached to a solid support; R 3 is hydrogen or an electron donating group having from 1 to 12 carbon atoms and from 0 to 4 heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and phosphorus; R 4 is hydrogen, alkyl having from 1 to 3 carbon atoms, aryl or electron donating-substituted aryl having 6-10 carbon atoms with 0-2 heteroatoms, or electron donating-substituted alkyl having from 1 to 3 carbon atoms; R 6 is alkyl having from 1 to 6 carbon atoms, alkylaryl having from 6 to 8 carbon atoms, —CH 2 —CONH 2 , —CH 2 CH 2 CONH 2 , or —(CH 2 ) k —CO—Xaa, wherein k is an integer equal to 1 or 2 and Xaa is an amino acid; and R 9 is a side chain of an amino acid selected from the group consisting of alanine, aspartic acid, glutamic acid, phenylalanine, glycine, histidine, lysine, leucine, methionine, asparagine, glutamine, arginine, serine, tryptophan, and tyrosine.