Structure-activity relationship studies of substituted arylsulfoanilides as antiproliferatives, which are mediated by the partial depletion of intracellular Ca(2+) stores, resulted in the identification of compounds with micromolar activity against lung cancer cells in a growth inhibition assay. Incorporating the substitution pattern of the best arylsulfoanilides onto the 3-phenyloxindole scaffold resulted in a potent arylsulfoanilide-oxindole hybrid, 27. Compound 27 inhibits cancer cell growth by partial depletion of intracellular Ca(2+) stores and phosphorylation of eIF2alpha.

A series of substituted 3,3-diphenyl-1,3-dihydro-indol-2-ones was synthesized from the corresponding isatins. The compounds were studied for cell growth inhibition mediated by partial depletion of intracellular Ca2+ stores that leads to phosphorylation of eIF2alpha. The diphenyloxindole (1) showed mechanism-specific antiproliferative activity that was comparable to known translation initiation inhibitors such as clotrimazole or troglitazone. SAR studies identified m'-tert-butyl and o-hydroxy substituted diphenyloxindole (25) as a lead compound for Ca2+-depletion-mediated inhibition of translation initiation.