Patent GB-992957-A (GB)
Title: New decapeptides and their manufacture
IPC: A61K38/00
Filed: 1961-06-02
Abstract: The invention comprises decapeptides of the formula L - seryl - L - tyrosyl - L - seryl - L - mercapto - lower alkyl - a  - amino - acetyl - L - glutaminyl - (or - L - glutamyl) - L - histidyl - L - phenylalanyl - L - a  - amino - lower alkyl - a  - amino - acetyl - L - tryptophyl - glycine whose mercapto group is optionally substituted by a lower alkyl radical, their functional derivatives such as esters, amides and N-substitution products such as N-acyl derivatives and compounds having amino protective groups, and their acid addition salts, wherein "lower alkyl" indicates 1-4 carbon atoms in the alkyl group, and the preparation thereof by condensing a heptapeptide L-a -mercapto-lower alkyl - a  - amino - acetyl - L - glutaminyl - L histidyl - L - phenylalanyl - L - a  amino - lower alkyl - a  - amino - acetyl - L - tryptophyl -glycine which contains an alkyl mercapto or a protected mercapto group and which has a free amino group and a free or esterified carboxyl group or the corresponding L-glutamyl peptide whose g -carboxyl group is protected by a tertiary butyl group, with a tripeptide of the formula L-seryl-L-tyrosyl-L-serine having a protected a -amino group and a carboxyl group in the form of its azide or its activated ester and, if desired, removing any protective groups or condensing the hexapeptide L-glutaminyl-L-histidyl - L - phenylalanyl - L - a  - amino-lower alkyl - a  - amino - acetyl - L - tryptophyl-glycine which has a free or esterified carboxyl group or the corresponding L-glutamyl peptide whose g -carboxyl group is protected by a tertiary butyl group with a tetra peptide L - seryl - L - tyrosyl - L - seryl L - - a  - mercapto lower alkyl-a -amino-acetic acid, which contains a protected mercapto group or a mercapto group substituted by a lower alkyl radical, a protected a -amino group and a carboxyl in the form of its azide or its activated ester and, if desired, removing any protective groups and, in either process if further desired, converting a base into an acid addition salt or a salt into a base thereof.  The L-a -mercapto lower alkyl-a -amino-acetyl group is a residue from cysteine, homocysteine or their S-alkyl derivatives or preferably methionine; L-a -amino-lower alkyl-a -amino-acetyl groups are L-arginyl, L-ornithyl and L-lypsyl.  Suitable protecting groups for amino groups include the tertiary butyloxycarbonyl group (BOC-) and for the mercapto group the benzyl group.  The compounds of the invention may also be prepared by condensing an octapeptide of the formula L-seryl-L-methionyl - L - glutaminyl - (or L - glutamyl)-L - histidyl - L - phenylalanyl - L - a  - amino-lower alkyl - a  - aminoacetyl - L - tryptophyl-glycine with L-seryl-L-tyrosine or a pentapeptide L-seryl - L - tyrosyl - L - seryl - L - a -mercapto - lower alkyl - a - aminoacetyl - L-glutamine (or glutamic acid) with a pentapeptide L - histidyl - L - phenylalanyl - L - a -amino-lower alkyl - a  - aminoacetyl - L - tryptophyl glycine.  The heptapeptide, H-Met-Glu(NH2)-His-Phe-Arg-Try-Gly-OH is prepared from BOC-MetOH and the hexpeptide ester after removing the BOC- and ester groups. BOC-Ser-Tyr-Ser-N3 is prepared from the corresponding hydrazide in turn prepared by reacting BOC-N3 with HSerOMe to give BOC-Ser-OMe, then forming BOC.SerNHNH2 and BOC.SerN3, reacting the azide with H.Tyr-Ser-OMe to give BOC-Ser-Tyr-Ser-OMe and finally reacting the ester with hydrazine. BOC-Ser-Tyr-SerOMe is also prepared by reacting H-Ser-Tyr-Ser-OMe (from the carbobenzoxy derivative and hydrogen) with BOC-p-nitrophenol.  H.Tyr-SerOMe is prepared from the hydrochloride salt by treatment with ammonia.  Specifications 872,332, 895,345, 992,951 are referred to.