TABLE 1.

Chemical structure of some common bile acids, including free bile acids, glycine/taurine-conjugated bile acids, and sulfated bile acids.

Abbreviation	Compound	R1	R2	R3	R4	R5
CA	Cholic acid	α-OH	H	α-OH	OH	OH
CDCA	Chenodeoxycholic acid	α-OH	H	α-OH	H	OH
DCA	Deoxycholic acid	α-OH	H	H	OH	OH
7-oxo-DCA	7-oxo-deoxycholic acid	α-OH	H	=O	OH	OH
LCA	Lithocholic acid	α-OH	H	H	H	OH
12-oxo-LCA	12-oxo-lithocholic acid	α-OH	H	H	=O	OH
UDCA	Ursodeoxycholic acid	α-OH	H	β-OH	H	OH
α-MCA	α-muricholic acid	α-OH	β-OH	α-OH	H	OH
β-MCA	β-muricholic acid	α-OH	β-OH	β-OH	H	OH
ω-MCA	ω-muricholic acid	α-OH	α-OH	β-OH	H	OH
HCA	Hyocholic acid	α-OH	α-OH	α-OH	H	OH
HDCA	Hyodeoxycholic acid	α-OH	α-OH	H	H	OH
7-oxo-HDCA	7-oxo-hyodeoxycholic acid	α-OH	α-OH	=O	H	OH
DHCA	Dehydrocholic acid	=O	H	=O	=O	OH
MDCA	Murideoxycholic acid	α-OH	β-OH	H	H	OH
Unconjugated						OH
Glycine conjugates						NHCH2CO2H
Taurine conjugates						NHCH2CH2SO3H
Sulfated BAs	HSO4

α-MCA, β-MCA and ω-MCA do not have corresponding glycine conjugated bile acids, while bile acids with carboxyl groups (7-oxo-DCA, 12-oxo-LCA, 7-oxo-HDCA) do not have corresponding taurine and glycine conjugates.