The mechanism of human adipocere formation

In adipocere, some specific fatty acids possessing higher melting points, together with soap, play an important role in the formation and stabilization of adipocere. These fatty acids were shown to be mainly 10-hydroxy stearic and 10-hydroxy palmitic acids. Slight amounts of 10-oxo stearic and 10-oxo palmitic acids, which have higher melting points than those of hydroxy fatty acids (OHFAs), exist in the adipocere as well. The substantial adipocere is formed and stabilized mainly by these specific fatty acids. The OHFA and oxo fatty acid (OXOFA) are biosynthesized by some bacterial enzymes. Various aerobic and anaerobic bacteria are involved in the formation of adipocere. For instance, microbial conversion of various unsaturated fatty acids to 10-OHFA by Micrococcus luteus was investigated. It turned out that 10-OHFA was synthesized only from fatty acids possessing cis-9-unsaturatin. It was also shown that 10-OHFAs were converted to the corresponding 10-OXOFAs but 10-OXO compounds were inactive as substrates. It was further found that the enzyme preparations from Flavobacterium meningosepticum solubilized by sonication catalyzed not only hydration of oleic acid to produce 10-hydroxy stearic acid, but also dehydrogenation of this product in the presence of deuterium. On the other hand, we found out that there was 10-hydroxy-12-octadecenoic acid (10-OHODA) in the linoleic acid in human adipocere and that there were 9-chloro-10-methoxy (9-methoxy-10-chloro) palmitic acid and 9-chloro-10-methoxy (9-methoxy-10-chloro) stearic acid in human neonate adipocere.