Takatori T
Department of Forensic Medicine, Faculty of Medicine, University of Tokyo, Japan.
Nihon Hoigaku Zasshi. 1993 Dec;47(6):435-44.
In the adipocere which is one of postmortem changes, some specific fatty acids possessing higher melting points together with soap play an important role in the formation of adipocere. These fatty acids were clarified to be mainly 10-hydroxystearic and 10-hydroxypalmitic acids. Moreover, slight amounts of 10-oxostearic and 10-oxopalmitic acids, which have higher melting points than those of hydroxy fatty acids, exist in the adipocere as well. The substantial adipocere is formed and stabilized by these specific fatty acids together with the soap. The hydroxy fatty acid (OHFA) and oxo fatty acid (OXOFA) are biosynthesized by some enzymes from bacteria. Various aerobic and anaerobic bacteria are involved in the formation of adipocere. For example, microbial conversion of various unsaturated fatty acids to 10-OHFA by Micrococcus luteus was investigated. As a result, 10-OHFA was synthesized only from fatty acids possessing cis-9-unsaturation. It was also clarified that 10-OHFAs were converted to the corresponding 10-OXOFAs but the 10-OXO compounds were inactive as substrates. Furthermore, the enzyme preparations from Flavobacterium meningosepticum solubilized by sonication catalyzed not only hydration of oleic acid to produce 10-hydroxystearic 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-OHLA) from linoleic acid in some kinds of adipocere. 10-OHFA existing in adipocere has been thought not to exist in a living body. However, recently 10-epoxy-12-octadecenoic acid (leukotoxin, LTx) which is one of lipid peroxides was found not only in rice plants but in polymorphonuclear leukocytes. It was also clarified that these polymorphonuclear leukocytes produced the same 10-OHLA as the compound found in adipocere. Since LTx was found from leukocytes related to inflammatory response, it has been interested in involvement of not only the basic mechanism of biological defense but also the mechanism of shock as a vasoactive substance. A postmortem change itself is little associated with a phenomenon on a living body. However, 10-OHLA found in adipocere existed also in polymorphonuclear leukocytes, suggesting that this compound metabolized from LTx is closely related to a biological reaction.
在尸蜡这种死后变化中，一些熔点较高的特定脂肪酸与肥皂一起在尸蜡形成过程中发挥重要作用。已明确这些脂肪酸主要是10 - 羟基硬脂酸和10 - 羟基棕榈酸。此外，尸蜡中还存在少量熔点高于羟基脂肪酸的10 - 氧代硬脂酸和10 - 氧代棕榈酸。这些特定脂肪酸与肥皂共同形成并稳定了大量的尸蜡。羟基脂肪酸（OHFA）和氧代脂肪酸（OXOFA）由细菌中的一些酶生物合成。各种需氧菌和厌氧菌都参与了尸蜡的形成。例如，研究了藤黄微球菌将各种不饱和脂肪酸微生物转化为10 - OHFA的过程。结果表明，仅从具有顺式 - 9 - 不饱和键的脂肪酸中合成了10 - OHFA。还明确了10 - OHFA被转化为相应的10 - OXOFA，但10 - OXO化合物作为底物无活性。此外，通过超声处理溶解的脑膜败血黄杆菌的酶制剂不仅催化油酸水合生成10 - 羟基硬脂酸，还在氘存在下催化该产物脱氢。另一方面，我们发现在某些类型的尸蜡中存在由亚油酸生成的10 - 羟基 - 12 - 十八碳烯酸（10 - OHLA）。一直认为尸蜡中存在的10 - OHFA在活体中不存在。然而，最近发现脂质过氧化物之一的10 - 环氧 - 12 - 十八碳烯酸（白细胞毒素，LTx）不仅存在于水稻植株中，还存在于多形核白细胞中。还明确这些多形核白细胞产生的10 - OHLA与在尸蜡中发现的化合物相同。由于LTx是从与炎症反应相关的白细胞中发现的，它不仅涉及生物防御的基本机制，还作为一种血管活性物质涉及休克机制，这引起了人们的兴趣。死后变化本身与活体现象几乎没有关联。然而，在尸蜡中发现的10 - OHLA也存在于多形核白细胞中，这表明这种由LTx代谢而来的化合物与生物反应密切相关。
