Identification of O-Alkyldihydroxyacetone Phosphate, O-Alkyldihydroxyacetone, and Diacyl Glyceryl Ethers after Enzymic Synthesis

O-Alkyldihydroxyacetone-P and O-alkyldihydroxyacetone were identified as intermediates in the biosynthesis of O-alkyl-linked lipids. The substrates for the initial reaction are dihydroxyacetone-P and fatty alcohols, and the cofactor requirements are coenzyme A, ATP, and Mg++. The enzyme complex that carries out this reaction was found in microsomes of preputial gland tumors. The keto-intermediates were identified by thin layer and gas-liquid chromatography of derivatives and standards prepared by the following techniques: LiAlH4 reduction, periodate oxidation before and after LiAlH4 reduction, acid and alkaline hydrolysis, and removal of the phosphate moiety by bacterial alkaline phosphatase. We analyzed the fatty alcohols and O-alkyl ethylene glycols resulting from these treatments as the acetates; the O-alkylglycerols were identified as the isopropylidene derivatives. Both keto-intermediates can be enzymically reduced with NADPH. After reduction of the ketone group of the phosphorylated intermediate, acylation can result in the formation of diacyl glyceryl ethers.