β-Apooxytetracycline is a potential impurity found in commercial preparations of oxytetracycline. β-Apooxytetracycline is a degradation product formed from oxytetracycline via acid hydrolysis. It has a relative potency of 0.1 compared with oxytetracycline for inhibiting the growth of aerobic sludge bacteria, an MIC50 value of 32 mg/L for tetracycline-sensitive strains of Pseudomonas, and MIC50 values of greater than 32 mg/L for tetracycline-sensitive strains of Agrobacterium, Moraxella, and Bacillus, as well as tetracycline-resistant strains of E. coli. β-Apooxytetracycline (10 mg/kg) is toxic to rats, decreasing body weight, disrupting blood cell counts, and inducing hepatocyte necrosis.

Cholic acid3-sulfate sodium是Cholic acid的一种代谢产物，属于初级胆汁酸。

Hercynine (Histidine-betaine) 是 Ergothioneine 的中间体 (前体) 和氧化还原代谢物，存在于细叶藻、酿酒裂糖菌和蜜蜂中。Hercynine 对 •OH 自由基无清除作用。

N-Desalkyludenafil 是 Udenafil 的代谢物。Udenafil 是一种PDE5抑制剂，用于研究勃起功能障碍。

Desoxycarbadox, derived from Carbadox, is a quinoxaline-di-N-oxide antibiotic compound.

Retinyl-β-D-glucoside is a naturally occurring and biologically active metabolites of vitamin A, and are found in fish and mammals.

5β-Dutasteride is the S configuration of Dutasteride. It is a potent inhibitor of both 5 alpha-reductase isozymes.

15-keto Latanoprost is a potential metabolite of latanoprost when administered to animals. 15-keto Latanoprost is also one of the common minor impurities found in commercial preparations of the bulk drug compound. Although much less potent that the parent compound latanoprost, 15-keto latanoprost still retains the ability to produce a small but measurable decrease (1 mm Hg) in the intraocular pressure of normal cynomolgus monkeys when administered at a dose of 1 μg/eye. 15-keto Latanoprost is also a miotic in the normal cat eye, causing an 8 mm Hg reduction in pupillary diameter at 5 μg/eye. Again, this is not as potent as many other F-type prostaglandins; for example, prostaglandin F2α will produce this degree of miosis at a dose of less than 1 μg/eye.

Calcitroic acid 为维生素 D 受体 (VDR) 激动剂，能够激活 VDR 介导的转录。它是 1,25-二羟基维生素 D3 的主要代谢物，在小鼠肝脏和粘膜中浓度最高，具有代谢稳定性和极低毒性。