Synthesis and structural optimization of multiple H-bonding region of diarylalkyl (thio)amides as novel TRPV1 antagonists.

Structural optimization of multiple H-bonding region and structure-activity relationship of diarylalkyl amides/thioamides as novel TRPV1 antagonists are described. In particular, we identified amide 34o and thioamides 35o and 35r, of which antagonistic activities were highly enhanced by an incorporation of cyano or vinyl-substituent to the multiple H-bonding region. They exhibited potent (45)Ca(2+) uptake inhibitions in rat DRG neuron with IC(50)s of 25, 32 and 28 nM, respectively.