Aha	aminoheptanoic acid
Abu(Aba)	2-aminobutyric acid (L-2-aminobutanoic acid
Apa	aminopropionic acid
Aib	aminoisobutyric acid (aminoisobutyrate)
Bu	2-aminobutyric acid (L-butyrine)
Cit	citrulline
ADMAdda	O-acetyl-9-O-desmethylAdda
Dha	dehydroalanine
Dhb	dehydrobutyrine
DMAdda	9-O-desmethylAdda
dmAdda	Adda demethylated at C-2, C-6, or C-8
E(OMe)	glutamic acid methylester
H(2)Y	dihydrotyrosine
(H4)Y	4,5,6,7-tetrahydrotyrosine
Har	homoarginine
Hil	homoisoleucine
Hph	homophenylalanine
Hty	homotyrosine
Kyn	kynurenine
Mdhb	N-methyldehydrobutyrine
M(O)	methionine-S-oxide
M(O2)	methionine S-sulfone
Mser	N-methylserine
Nfk	N-formylkynurenine
Oia	oxindolyalanine
Y(OMe)	methoxytyrosine