Reuterin (3-hydroxypropionaldehyde) is the organic compound with the formula HOCHCHCHO.  It is a bifunctional molecule, containing both a hydroxy and aldehyde functional groups.
The name reuterin is derived from Lactobacillus reuteri, which produces the compound biosynthetically from glycerol as a broad-spectrum antibiotic (bacteriocin). L. reuteri itself is named after the microbiologist Gerhard Reuter, who did early work in distinguishing it as a distinct species.