Quinoline-5, 8-dione-based compounds were designed from the structure of the geldanamycin-bound Hsp-90 active site. The active site model predicted that aromatic substituents should be present at the 2-position, to take advantage of a hydrophobic pocket, and amino substituents should be present at the 6-or 7-position. COMPARE analysis revealed that the LC50 profile of 2-phenyl-6-(2-chloroethylamino) quinoline-5, 8-dione ...