Table 1. The inhibitory activities (IC₅₀, μM) of benzenesulfonamide derivatives against MβL ImiS ^a .

P-Substituted compd.	IC50	M-Substituted compd.	IC50	O-Substituted compd.	IC50
1a	7.5 ± 0.3	2a	0.15 ± 0.04	3e	5.4 ± 0.2
1b	2.7 ± 0.4	2b	0.14 ± 0.07	3f	4.6 ± 0.2
1c	4.8 ± 0.1	2c	0.86 ± 0.04	RS	6.8 ± 0.5
1d	9.3 ± 0.3	2d	0.31 ± 0.05
1e	5.1 ± 0.5	2e	0.44 ± 0.01
1f	3.3 ± 0.1	2f	0.23 ± 0.08
1g	7.3 ± 0.2	2g	0.11 ± 0.02
1h	3.5 ± 0.2	2h	0.16 ± 0.08
1i	5.6 ± 0.7
1j	4.1 ± 0.6

^aThe substrate used was imipenem and inhibitor concentrations were varied between 0.01 and 20 μM. Enzyme and inhibitors were preincubated for 3 h before testing.