Antagonist activity of β-lactams 1a–d and analogue 9d at rTRPM8 channels in microfluorometry assays and patch-clamp experiments

CompoundRConfigurationCa2+ microfluorometryPatch clamp
IC50 (µM)95% confidence intervalsIC50 (µM)95% confidence intervals
1aOtBu3S,4S,2'S1.06 ± 1.210.72 to 1.550.97 ± 1.560.38 to 2.45
1bOtBu3S,4S,2'R0.72 ± 0.120.64 to 0.801.21 ± 0.40.82 to 1.72
1cOtBu3R,4R,2'S4.48 ± 0.803.62 to 5.562.94 ± 0.752.27 to 3.69
1dOtBu3R,4R,2'R5.02 ± 1.503.76 to 6.773.34 ± 0.82.40 to 5.52
9dNHiBu3R,4R,2'R0.41 ± 0.100.36 to 0.460.90 ± 1.250.57 to 1.42
AMTBNAND7.3 ± 1.58.82 to 7.85NDND

ND: no determined; NA: not applicable; AMTB: N-(3-aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide hydrochloride; IC50: concentration exerting a half-maximal inhibition; rTRPM8: rat transient receptor potential melastatin channel, subtype 8; R: substituent at the 4-position; OtBu: tert-butyl ester; NHiBu: N-isobutyl amide