Glycodeoxycholic acid (GDCA), a bile acid, is formed in the liver from chenodeoxycholate and glycine. GDCA was one of twenty-five plasma metabolites, which were significantly different among asthma and healthy controls. Besides, GDCA was elevated in patients with acetaminophen-induced acute liver failure (AALF) and was significantly increased in non-surviving AALF patients compared with survivors. Thus GDCA level could serve as a prognostic biomarker for AALF patients.

Isopilocarpine is a diastereomer of pilocarpine. Isopilocarpine coexists with pilocarpine in nature and is also a degradation product of pilocarpine after oral administration to humans. It can be found in the leaves of some Pilocarpus species. Pilocarpine targets the muscarinic receptors and is approved for treatment of xerostomia. Isopilocarpine is often present in formulations of pilocarpine but has no appreciable effect on muscarinic receptors.