Cyclohexyl hexadecanoate, hexadecyl propionate, and N-(3-hydroxypropionyl)pentadecanamide, respectively ester, retroester, and retroamide derivatives of N-palmitoylethanolamine, represent the first selective inhibitors of "N-palmitoylethanolamine hydrolase" described so far. These compounds are devoid of affinity for CB(1) and CB(2) receptors and characterized by high percentages of inhibition of N-palmitoylethanolamine-selective acid amidase (84.0, 70.5, and 76.7% inhibition at 100 microM, respectively) with much lower inhibitory effect on either fatty acid amide hydrolase or the uptake of anandamide.
Vandevoorde, S., Tsuboi, K., Ueda, N., Jonsson, K.-O., Fowler, C. J., & Lambert, D. (2003). Esters, retroesters, and a retroamide of palmitic acid: pool for the first selective inhibitors of N-palmitoylethanolamine-selective acid amidase. Journal of Medicinal Chemistry, 46(21), 4373-4376. https://doi.org/10.1021/jm0340795 (Original work published 2003)