D-Saccharic acid potassium salt is a compound formed from oxidizing sugars which can be used to test for the presence of hepatic enzyme induction. Studies indicate that D-glucuronolactone dehydrogenase oxidizes D-Saccharic acid potassium salt into D-glucaro-l4;63-dilactone.

Biotin-MBP Derivatized Peptide

N-methylnicotinamide is a metabolite of niacin (or nicotinamide) and is commonly found in human urine. However low levels of urinary excretion of N-methylnicotinamide indicates niacin deficiency. In patients with liver cirrhosis nicotinamide methylation is increased leading to a rise in urinary N-methylnicotinamide. N-methylnicotinamide has been found to be a microbial metabolite.