Ak. Batta et al., SYNTHESIS AND INTESTINAL METABOLISM OF URSODEOXYCHOLIC ACID CONJUGATEWITH AN ANTIINFLAMMATORY AGENT, 5-AMINOSALICYLIC ACID, Journal of lipid research, 39(8), 1998, pp. 1641-1646
5-Aminosalicylic acid conjugate of ursodeoxycholic acid was synthesize
d in above 90% yield by adding a basic solution of 5-aminosalicylic ac
id into the mixed anhydride formed with ursodeoxycholic acid and ethyl
chloroformate. The 5-aminosalicylic acid conjugate of ursodeoxycholic
acid was poorly secreted into the bile and was deconjugated with chol
ylglycine hydrolase and Clostridium perfringens, that deconjugate natu
rally occurring glycine and taurine conjugates of bile acids, However,
ursodeoxycholic acid 5-aminosalicylic acid conjugate was not absorbed
from the duodenum but was concentrated in the colon where it was part
ially hydrolyzed by the intestinal bacteria to ursodeoxycholic acid an
d 5-aminosalicylic acid. We believe that this unique conjugation of ur
sodeoxycholic acid with 5-aminosalicylic acid may facilitate the trans
port of both 5-aminosalicylic acid and ursodeoxycholic acid to the col
on and may be useful for the treatment of colonic inflammatory bowel d
iseases, ulcerative colitis and Crohn's disease.