In enzymology, a benzyl-2-methyl-hydroxybutyrate dehydrogenase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are benzyl (2R,3S)-2-methyl-3-hydroxybutanoate and NADP<sup>+</sup>, whereas its 3 products are benzyl 2-methyl-3-oxobutanoate, NADPH, and H<sup>+</sup>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is benzyl-(2R,3S)-2-methyl-3-hydroxybutanoate:NADP<sup>+</sup> 3-oxidoreductase. This enzyme is also called benzyl 2-methyl-3-hydroxybutyrate dehydrogenase.