Table 1.

Structures of selected NAAA inhibitors

			IC50 (nM)
	R	R1
1			2,960 ± 300
2			>100,000
3 (S)-OOPP			420 ± 20
4			>100,000
5			>100,000
6 (R)-OOPP			6000 ± 600

Values reported are the concentrations required to inhibit NAAA activity by 50% (IC₅₀) in nM and are expressed as mean ± SEM of at least three independent experiments. They were calculated from concentration response curves using nonlinear regression analysis in the Prism 4.0 software package.