2,3-diaminopropionic acid
2,3-dihydroxybenzoic acid
2,4-diaminobutyric acid
3,5-dihydroxyphenylglycine
4-hydroxyphenylglycine
N5-formyl-N5-hydroxyornithine
N5-hydroxyornithine
R-beta-hydroxytyrosine
alanine
arginine
asparagine
aspartic acid
beta-alanine
cysteine
glutamic acid
glutamine
glycine
histidine
isoleucine
leucine
lysine
ornithine
phenylalanine
pipecolic acid
proline
serine
threonine
tryptophan
tyrosine
valine
