| abstract |
NEW MATERIAL:Compounds of formula I (R 1 -R 4 are lower alkoxy or sulfoxy, provided that at least two thereof are sulfoxy) and salts thereof. n EXAMPLE: Ellagic acid 3,3'4,4'-tetra(sulfate potassium salt). n USE: An aldose reductase inhibitor. n PREPARATION: An ellagic acid derivative of formula II (X 1 -X 4 are hydroxy or lower alkoxy) is sulfated, subsequently hydrolyzed and neutralized as necessary to obtain the objective compound of formula I. The reaction is carried out, e.g. by using chlorosulfonic acid preferably in the presence of a tertiary amine such as pyridine or N,N-dimethylaniline. An aldose reductase inhibitor containing the compound of formula I as the active component is suitable for preparation of a tablet, a capsule, an injection, etc., by the conventional method using a general carrier. n COPYRIGHT: (C)1992,JPO&Japio |