Amino acid derivatives

DETAILED DESCRIPTION OF THE INVENTION The invention in its broad aspects includes substituted acyl derivatives of amino acids having formula I above.
The substituted acyl groups refer to the side chains on the carbon beta to the nitrogen atom.
The one side chain has one or two sulfur containing groups and the second side chain has one nitrogen containing group.
Within the class defined by formula I, because of their properties, certain subgroups are preferred.
Compounds in the group represented by formula I which are derived from or include the structure of the amino acids glycine, alanine, leucine, threonine, phenylalanine, lysine, arginine, glutamine, histidine, methionine, serine, cysteine, tyrosine, valine, asparagine, glutamic acid, proline, hydroxyproline, phenylglycine or tryptophane are broadly preferred.
Preferred modifications are compounds of formula I wherein R is hydroxy; R.
sub.
1 is hydrogen, lower alkanoyl or amino(imino)methyl [particularly hydrogen, methyl, acetyl or amino(imino)methyl]; R.
sub.
2 is hydrogen, lower alkyl (particularly hydrogen or methyl) or phenyl-lower alkylene (particularly benzyl), most particuarly R.
sub.
2 is hydrogen; R.
sub.
3 is hydrogen, lower alkanoyl or benzoyl (particularly hydrogen, or acetyl); A is hydrogen; B is lower alkyl, guanidino-lower alkylene (particularly guanidinopropyl), amino-lower alkylene (particularly amino-C.
sub.
3 -C.
sub.
4 -lower alkylene) or phenyl-lower alkylene (particularly phenylmethyl); or A and B complete a 5- or 6-membered ring; m is 0, 3 or 4 and n is 0 or 1, but not both m and n are 0.
Especially preferred are those compounds of formula I which are derived from proline and have the formula ##STR4## The symbols have the same preferred meanings described above.
The lower alkyl groups represented by any of the variables include straight and branched chain hydrocarbon radicals from methyl to heptyl, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl and the like.
The lower alkylene groups are of the same kind also having 1 to 7 carbons