THE STUDY OF MOLECULAR MARKERS OF HUMAN ACTIVITY - THE USE OF COPROSTANOL IN THE SOIL AS AN INDICATOR OF HUMAN FECAL MATERIAL
THE STUDY OF MOLECULAR MARKERS OF HUMAN ACTIVITY - THE USE OF COPROSTANOL IN THE SOIL AS AN INDICATOR OF HUMAN FECAL MATERIAL
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DOI：
10.1006/jasc.1994.1061
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发表时间：
1994-09-01
影响因子：
2.8
通讯作者：
OTTAWAY, J
中科院分区：
文献类型：
--
作者：
BETHELL, PH;GOAD, LJ;OTTAWAY, J
粪甾烷醇（5β-胆甾烷-3β-ol）是胆固醇的代谢产物，由哺乳动物肠道中的微生物作用形成（肠道外、哺乳动物组织和沉积物中胆固醇减少的常见产物是5α-胆甾烷-3β-ol）。 粪甾烷醇是人类粪便中的主要甾醇，并且已作为海洋和湖泊沉积物中（现代）污水污染的标志物进行常规研究。 这导致人们在考古土壤中寻找粪甾烷醇，以检测粪便物质的存在。 对土壤总脂质进行溶剂萃取，然后使用薄层色谱进行分级，以分离土壤中存在的类固醇。 然后通过组合气相色谱/质谱 (GC/MS) 进行分析，使用选择离子监测 (SIM) 来检测和量化特定化合物。 对一系列来源的样本进行了分析，包括现代厕所沉积物、一个 17 世纪的衣柜、一个中世纪的衣柜和两个疑似罗马污水坑。 粪甾烷醇及其同系物不仅在现代和老化的粪便样品中被发现，而且在对照样品中也被检测到，这表明它在环境中普遍存在，尽管浓度较低。 然而，通过测量 5β-甾烷醇的相对丰度和比例，可以建立粪便物质的独特化学特征，而与土壤中粪甾烷醇的简单存在无关。 结果表明，当在适当的相对丰度中发现粪甾烷醇及其在肠道中通过相同微生物机制产生的同系物时，它们是土壤中粪便存在的可靠标记。 因此，一种分析土壤中保存的极少量特定分子标记化合物的方法已应用于考古材料，从而能够在传统物理分析方法可能无法成功的情况下识别出特定的有机残留物。
Coprostanol (5beta-cholestan-3beta-ol) is a metabolic product of cholesterol, formed by microbial action in the mammalian gut (the usual product of cholesterol reduction outside the gut, in mammalian tissues and sediments, is 5alpha-cholestan-3beta-ol). Coprostanol is the major sterol in human faeces, and has been routinely studied as a marker of (modern) sewage pollution in marine and lacustrine sediments. This has led to the search for coprostanol in archaeological soils, in order to detect the presence of faecal material. Solvent extraction of the soil total lipids was followed by fractionation using thin layer chromatography, to isolate the steroids present in the soil. These were then analysed by combined gas chromatography/mass spectrometry (GC/MS), using selected ion monitoring (SIM) to detect and quantify specific compounds. Samples from a range of sources were analysed, including modern latrine deposits, a 17th-century garderobe, a mediaeval garderobe and two suspected Roman cess-pits. Coprostanol and its homologues were detected not only in the modern and aged cess samples, but also in the control samples, suggesting its ubiquitous occurrence in the environment, albeit at a low concentration. However, by measuring the relative abundances and ratios of the 5beta-stanols, a chemical signature distinctive of faecal material could be established, independent of the simple occurrence of coprostanol in the soil. It was shown that coprostanol, and its homologues produced by the same microbial mechanism in the gut, were reliable markers of the presence of faeces in soils when found in the appropriate relative abundances. A method of analysing very small quantities of specific molecular marker compounds preserved in soils has thus been applied to archaeological materials, enabling a particular organic residue to be identified where conventional physical methods of analysis might not be successful.