Table 1.

Human CA isoenzymes (hCA I and II) inhibition value of the compounds (9–16) by the esterase method with 4-nitrophenyl acetate as substrate.

	IC50 (nM)				Ki (nM)
Compounds	hCA I	r2	hCA II	r2	hCA I	hCA II
9	554.8	0.9759	586.3	0.9723	506.3 ± 133.5	624.6 ± 168.2
10	491.8	0.9816	620.4	0.9565	476.5 ± 81.1	561.5 ± 133.9
11	483.9	0.9743	486.3	0.9688	533.1 ± 187.8	469.0 ± 63.0
12	402.9	0.9646	559.3	0.9814	377.6 ± 113.8	520.6 ± 131.8
13	493.2	0.9709	536.0	0.9737	462.2 ± 133.5	587.3 ± 188.5
14	404.8	0.9817	470.5	0.9602	316.7 ± 9.6	412.5 ± 115.4
15	416.5	0.9815	534.3	0.9631	325.8 ± 29.4	430.3 ± 87.3
16	528.2	0.9710	458.6	0.9772	472.0 ± 57.5	591.9 ± 134.5
AZA	985.8	0.9811	489.4	0.9972	278.8 ± 44.3	293.4 ± 46.4

Acetazolamide (AZA) was used as a standard inhibitor for all hCA isoenzymes. The results were expressed as nanomolar (nM).