Long-chain cyclic acetals of glycerol: metabolism of the stereomeric 1,3-dioxanes and 1,3-dioxolanes in myelinating rat brain

Abstract

The metabolism of the stereomeric cyclic glycerol acetals of [1-14C] hexadecanal was studied in myelinating rat brain. It was found that the four isomers, cis- and trans-2-pentadecyl-5-hydroxy-l,3-dioxanes and cis- and trans-2-pentadecyl-4-hydroxymethyl-1,3-dioxolanes, were utilized by the tissue at different rates. The acetals were primarily metabolized via a ring-opening mechanism leading to palmitic acid, some of which was subsequently elongated–desaturated. Only the five-membered ring isomers were incorporated as intact acetals into both neutral and polar brain lipids.

Keywords

• 2-pentadecyl-5-hydroxy-1,3-dioxane
• 2-pentadecyl-4-hydroxymethyl-1,3-dioxolane
• enzymic acetal cleavage