comparison of the gsh conjugation of biu with that of its analogue alpha-bromoisovaleric acid ( bi , which lacks the amide-linked urea group ) revealed an opposite stereoselectivity : while ( r ) -biu was conjugated faster than ( s ) -biu , the ( r ) enantiomer of the acid was conjugated more slowly than ( s ) -bi .
C0041942
urea
C0006226
biu