In enzymology, a pterocarpin synthase () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are medicarpin, NADP<sup>+</sup>, and H<sub>2</sub>O, whereas its 3 products are vestitone, 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 medicarpin:NADP<sup>+</sup> 2'-oxidoreductase. This enzyme is also called pterocarpan synthase. This enzyme participates in isoflavonoid biosynthesis.