WF 3681 was isolated from Chaetomella sp. as a novel inhibitor of aldose reductase by researchers at Fujisawa Co. Japan in 1987, exhibiting an IC50 of 2.5 x 10-7 M. WF 3681 does not significantly reduce accumulation of sorbitol in rat sciatic nerves of diabetic rats. The structure of WF 3681 was confirmed in 1988.