THE ABSOLUTE STEREOCHEMICAL COURSE OF CITRIC ACID BIOSYNTHESIS

Abstract
If a molecule of biosynthetically formed citric acid is viewed from the side opposite the middle COOH group, then moving from [long dash]OH in a counterclockwise direction the first [long dash] CH2COOH is derived from acetyl-CoA, and the second from oxaloacetate. The enzymatic addition of water to cis-aconitate to give citrate is trans. The enzymatic addition of water to 5-dehydroshikimate to give 5-dehydroquinate is cis.