the natural amino acid is therefore formulated as 3- ( 2,5-ss-dicysteinyl-3,4-dihydroxyphenyl ) alanine ( 2,5-ss-dicysteinyldopa ) , which may be formed by two consecutive additions of cysteine , first to dopaquinone and then to 5-s-cysteinyldopaquinone .
C0002520
amino
C0001898
alanine