|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
URB754 was originally reported by Piomelli et al. to be a potent, noncompetitive inhibitor of monoacylglycerol lipase. However, recent studies have shown that URB754 failed to inhibit recombinant MGL, and brain FAAH activity was also resistant to URB754. In a later study by Piomelli et al. showed that the MGL-inhibitory activity attributed to URB754 is in fact due to a chemical impurity present in the commercial sample, identified as bis(methylthio)mercurane.
- Makara JK, Mor M, Fegley D, Szabó SI, Kathuria S, Astarita G, Duranti A, Tontini A, Tarzia G, Rivara S, Freund TF, Piomelli D (2005). "Selective inhibition of 2-AG hydrolysis enhances endocannabinoid signaling in hippocampus". Nat. Neurosci. 8 (9): 1139–41.
- Saario SM, Palomäki V, Lehtonen M, Nevalainen T, Järvinen T, Laitinen JT (2006). "URB754 has no effect on the hydrolysis or signaling capacity of 2-AG in the rat brain". Chem. Biol. 13 (8): 811–4.
- Tarzia, G; et al. (2007). "Identification of a bioactive impurity in a commercial sample of 6-methyl-2-p-tolylaminobenzo[d][1,3]oxazin-4-one (URB754.". Ann Chim. 97 (9): 887–94.