Table 5. TRPA1 Potency and Metabolic Stability of Compounds 18 and 34e–g^a.

compound	hTRPA1 IC50 [nM]	rTRPA1 IC50 [nM]	rHeps [L/h/kg]	hLMs [L/h/kg]	log D (HPLC)
18	16	63	2.4	0.38	3.0
34e	21	200	2.3	0.48	n.d.
34f	55	680	3.2	0.68	3.4
34g	41	650	1.8	0.44	3.8

^aCompound 18: fu% rat = 6%; brain= 4.3%; mouse = 8.1%; human = 12%, guinea pig = 9.7%.