Compound 3e (hCAIX/XII-IN-7) is a potent inhibitor of human carbonic anhydrase (hCA) isozymes IX and XII, displaying inhibitory constants (Kis) of 503.7 nM for hCA IX and 59 nM for hCA XII, while also showing activity against hCA I and II with Kis of 3.2 nM and 9.2 nM, respectively. It holds potential for research into hypoxic tumors [1].

CA IX (human):3.2 nM (Ki), CA XII (human):9.2 nM (Ki), CA (human):503.7 nM (Ki), CA II (human):59 nM (Ki)