In enzymology, a 3-methylbutanal reductase is an enzyme that catalyzes the chemical reaction 3-methylbutan-1-ol + NAD+ ⇌ {\displaystyle \rightleftharpoons } 3-methylbutanal + NADH + H+The three substrates of this enzyme are 3-methylbutan-1-ol, NAD+, and NADP+, whereas its four products are 3-methylbutanal, NADH, NADPH, and H+. Wikipedia