What is "prostanoic acid"

n. (context biochemistry English) a C₂₀ fatty acid, containing a cyclopentane ring, that is the basis of the prostaglandins

Prostanoic acid (7-[(1S,2S)-2-octylcyclopentyl]heptanoic acid) is a saturated fatty acid which contains a cyclopentane ring. Its derivatives are prostaglandins - physiologically active lipid substances. Prostanoic acid is not found in nature, but it can be synthesized in vitro.