Phosphonoacetaldehyde reductase (NADH) (, PhpC) is an enzyme with systematic name 2-hydroxyethylphosphonate:NAD<sup>+</sup> oxidoreductase. This enzyme catalyses the following chemical reaction
The enzyme from Streptomyces viridochromogenes catalyses a step in the biosynthesis of phosphinothricin tripeptide, the reduction of phosphonoacetaldehyde to 2-hydroxyethylphosphonic acid.