In enzymology, a glucuronate reductase (EC 184.108.40.206) is an enzyme that catalyzes the chemical reaction
L-gulonate + NADP+
D-glucuronate + NADPH + H+
Thus, the two substrates of this enzyme are L-gulonate and NADP+, whereas its 3 products are D-glucuronate, NADPH, and H+.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-gulonate:NADP+ 6-oxidoreductase. Other names in common use include aldehyde reductase, L-hexonate:NADP dehydrogenase, TPN-L-gulonate dehydrogenase, aldehyde reductase II, NADP-L-gulonate dehydrogenase, D-glucuronate dehydrogenase, D-glucuronate reductase, and L-glucuronate reductase (incorrect). This enzyme participates in pentose and glucuronate interconversions and ascorbate and aldarate metabolism.