Bacterial acetylation of 5-aminosalicylic acid in faecal suspensions cultured under aerobic and anaerobic conditions

Eur J Clin Pharmacol. 1992;43(2):189-92. doi: 10.1007/BF01740669.


After oral administration of 5-aminosalicylic acid a substantial proportion of the acetylated form is excreted in the faeces. We have studied the role of the faecal microflora in acetylating 5-aminosalicylic acid. In faeces incubated under both aerobic and anaerobic conditions there was acetylation of 5-aminosalicylic acid. Of the anaerobic bacteria isolated from a 10(8) faecal dilution 44% were able to acetylate 5-aminosalicylic acid. We conclude that the normal faecal microflora contribute to the acetylation of 5-aminosalicylic acid.

MeSH terms

  • Acetylation
  • Aerobiosis
  • Aminosalicylic Acids / metabolism*
  • Anaerobiosis
  • Bacteria / metabolism*
  • Bacteriological Techniques
  • Feces / microbiology*
  • Humans
  • Mesalamine


  • Aminosalicylic Acids
  • Mesalamine