Alrestatin is an inhibitor of aldose reductase, an enzyme involved in the pathogenesis of complications of diabetes mellitus, including diabetic neuropathy.

[1][2] Alrestat was first synthesized in 1969 and was the first aldose reductase inhibitor (ARI) with oral bioavailability to undergo clinical trials, in the late 1970s and early 1980s.

Low-quality trials and a high incidence of adverse effects (particularly hepatotoxicity) led to termination of its development, and it was never in clinical use.

[3][4] It is structurally related to tolrestat, another ARI that was briefly marketed before being withdrawn in 1997.

Alrestatin can be synthesized by the reaction of naphthalic anhydride with glycine.