Table 1.

PXR LBD binding activities of rifampicin analogs

Compound	Group	PXR LBD binding [IC50 ± SD (µM)]	FC*
T0901317	NA	0.004 ± 0.0003	0.0015
SR12813	NA	0.026 ± 0.003	0.0096
Rifampicin	1	2.7 ± 0.4	1
Rifamycin O	1	4.1 ± 0.4	1.5
Rifaximin	1	11.4 ± 3.3	4.2
Rifabutin	1	11.8 ± 4.4	4.4
Rifapentine	1	5.7 ± 1.6	2.1
Rifamycin	2	0.067 ± 0.009	0.025
3-Formyl Rifamycin	2	0.054 ± 0.01	0.020
Rifamycin S	2	0.054 ± 0.014	0.020
3-Bromo Rifamycin S	2	0.057 ± 0.011	0.021

^*FC, fold change, calculated by dividing a compound’s IC₅₀ value by that of rifampicin.