In terms of its structure, it is the alkali metal salt of the conjugate base of 3-hydroxy-1,2-cyclobutenedione (the enolate of 1,2,3-cyclobutanetrione), a planar molecule related to squaric acid.

[1] It is an unusual mycotoxin, a feed contaminant that is lethal to fowl, especially ducklings.

Moniliformin actually causes competitive inhibition of the activity of pyruvate dehydrogenase complex of respiratory reaction, which prevents pyruvic acid, product of glycolysis, to convert to acetyl-CoA.

[2][3][4] Ultrastructural examination of right ventricular wall of 9 month old female mink (Mustela vison) fed acute doses of moniliformin (2.2 and 2.8 mg/kg diet) and sub-acute doses (1.5 to 3.2 mg/kg diet) reveals significant damage to myofiber, mitochondria, Z and M lines and sarcoplasmic reticulum as well as increased extracellular collagen deposition.

[clarification needed] Minks are considered most sensitive mammals to the toxicity of moniliformin.