Synthesis and characterization of complexes of a novel proton transfer salt and their inhibition studies on carbonic anhydrase isoenzymes

Figures & data

Figure 1. Syntheses of compounds 1–6 (a for 1 and b for 2, 3, 4, 6 and c for 5).

Figure 2. An ORTEP drawing of asymmetric unit of 2 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.

Figure 3. An ORTEP drawing of asymmetric unit of 3 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.

Figure 4. An ORTEP drawing of asymmetric unit of 4 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.

Figure 5. An ORTEP drawing of asymmetric unit of 5 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.

Figure 6. An ORTEP drawing of asymmetric unit of 6 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.

Table 1. Human carbonic anhydrase isozymes (hCA I and hCA II) inhibition data with newly synthesized compounds by an esterase assay with 4-nitrophenylacetate as substrate.

Esterase IC50^a,b (mM)
Compound	hCA I	hCA II
AAZ	4.33 × 10^−3± 0.0002	3.24 × 10^−3± 0.0002
DPC	No Inhibition	No Inhibition
ClABT	0.85 ± 0.02	0.82 ± 0.006
FeClABT	0.36 ± 0.005	0.27 ± 0.005
CoClABT	0.32 ± 0.007	0.30 ± 0.004
NiClABT	0.30 ± 0.004	0.27 ± 0.003
CuClABT	0.29 ± 0.005	0.27 ± 0.003
1	0.76 ± 0.002	0.74 ± 0.007
2	0.26 ± 0.014	0.24 ± 0.002
3	0.17 ± 0.003	0.15 ± 0.006
4	0.16 ± 0.006	0.15 ± 0.004
5	0.16 ± 0.001	0.14 ± 0.003
6	0.17 ± 0.005	0.15 ± 0.010

AAZ was used as reference compound.

^aMean ± standard error, from three different assays.

^bp < 0.0001 for all analysis.