D. Carbonic anhydrase activity of acylpiperidine and dihydrobenzopyran libraries In order to bias subsets of members toward activity in several multi-test assays, known pharmacophoric elements were incorporated into both the acypiperidine and the dihydrobenzopyran libraries (33,34). These included the arylsulfonamide moiety, a known pharmacophore versus the enzyme carbonic anhydrase (CA) . Photoelution of ligands from the resin of both libraries and screening versus human CAli (hCAII), provided novel inhibitors with Ki values covering a wide potency range (34). The acylpiperidine library was determined to contain approximately 6% actives and the dihydrobenzopyran approximately 1.4% actives. These observations were consistent with the percentage of primary sulfonamides incorporated into the two libraries, that is, 10% and 3% respectively. Four actives from the acylpiperidine library and one from the dihydrobenzopyran library versus hCAII are shown in Figure 22. All five compounds were among those subsequently resynthesized in solution; structural and biological analysis confirmed the results obtained directly from the library.