Table 1. The inhibition assay against CA IX, CA I and CA II in vitro.

Compounds	IC50 (nM)			Selectivity ratios (I/IX)	Selectivity ratios (II/IX)
	CA IX	CA I	CA II
AZA	7.72	509.60	37.59	66.01	4.87
EZA	0.25	67.64	4.83	270.56	19.32
1a	2.86	197.64	60.93	69.10	21.30
1b	25.75	866.74	166.58	33.66	6.47
2a	4.14	423.42	12.94	102.28	3.13
2b	42.23	1541.18	239.58	36.50	5.67
3a	3.42	660.65	22.86	193.17	6.68
3b	18.98	772.88	276.83	40.72	14.58
4a	0.47	693.64	25.58	1475.83	54.42
4b	25.50	664.71	908.13	26.07	35.61
5a	0.30	266.56	2.09	888.53	6.97
5b	54.35	44.38	20.75	0.82	0.38
6a	0.48	503.74	749.28	1049.46	1561
6b	>104	60.46	142.48	—	—
7a	0.12	631.92	11.82	5266	98.50
7b	4.42	1341.59	949.64	303.53	214.85