Abstract Accumulation of intracellular sorbitol, formed from glucose by aldose reductase, is believed to play an important role in the development of certain chronic complications of diabetes mellitus. Several 1-(naphthalenylsulfonyl) hydantoins inhibit aldose reductase isolated from bovine lens in vitro, and decrease galactitol formation in sciatic nerves of galactosemic rats in vivo. The 5-bromo analogue (entry 12, table I) was found to be the ...