Simulated degradation of glyceryl ethers by hydrous and flash pyrolysis

Hydrous and flash pyrolysis were carried out on phytanyl ethers isolated fr om a methanogen (Methanosarcina barkeri), a haloalkaphile (Haloalkaphile sp .) and a thermoncidophile (Sulfolobus sulfotaricus). No thermal alteration products of the intact ether lipids were observed below 150 degrees C. From 150-300 degrees C, slight pyrolysis of the intact glyceryl ethers was obse rved, although recovery of the parent compounds averaged >95%. As pyrolysis temperature increased, the alcohol and aldehyde were the first products fo rmed following direct cleavage of the ether bond. Ar 600 degrees C, the cor responding alkene also became a dominant flash pyrolysis product. With incr eases in pyrolysis temperature to 900 degrees C, increasing amounts of vola tile alkenes were produced. Based on the observed fragmentation patterns, w e suggest that phytanol is first cleaved from the intact glyceryl ethers, f ollowed by degradation of the phytanol to the corresponding alkanes or shor ter chain components. Tn addition,as shown by other investigators, the alte ration products may also be directly incorporated into higher molecular wei ght fractions. (C) 1998 Elsevier Science Ltd. All rights reserved.