Background:

Pyrocatechuic acid is a normal human benzoic acid metabolite found in plasma, and has increased levels after aspirin ingestion.

Pyrocatechuic acid (2,3-Dihydroxybenzoic acid) is a normal human benzoic acid metabolite found in plasma, and has increased levels after aspirin ingestion[1].

参考文献:
[1]. Grootveld M, et al. 2,3-Dihydroxybenzoic acid is a product of human aspirin metabolism. Biochem Pharmacol. 1988 Jan 15;37(2):271-80.