Origin of stanols in young lacustrine sediments
Origin of stanols in young lacustrine sediments
复制标题
年轻湖相沉积物中甾烷醇的起源
作者：
M. Nishimura
类固醇骨架已被广泛用作古代沉积物 1-7 和石油 8 中有机物质的生物起源的标记。然而，人们对近期沉积物中甾醇（甾烷醇和甾烷醇）的起源和命运知之甚少。这里报道了生物源甾醇（饱和甾醇）对湖泊沉积物的重要贡献，并讨论了其地球化学意义。据报道，现代和古代沉积物中存在甾烷醇，以及藻类中常见的未改变的甾醇（不饱和甾醇）9-12。鉴于活生物体中甾烷醇的含量很少，这一现象已被用作证据，证明天然存在的甾醇在地质时期发生了部分还原。在当代湖泊沉积物中也发现了甾烷醇13-17。基于原位培养下 14C-胆固醇转化为 14C-胆固醇，Gaskell 和 Eglinton17,18 提出，年轻沉积物中的此类甾烷醇源自沉积后微生物还原的甾烷醇。
STEROIDAL skeletons have been widely used as markers of the biological origin of organic material in ancient sediments1–7 and petroleum8. Nevertheless, the origin and fate of sterols (stanols and stenols) in recent sediments are poorly understood. Here the significant contribution of organism-derived stanols (saturated sterols) to lacustrine sediments is reported and the geochemical significance discussed. The presence of stanols in recent and ancient sediments, together with unaltered stenols (unsaturated sterols) commonly found in algae, has been reported9–12. In view of the rare abundance of stanols in living organisms, this occurrence has been used as evidence that partial reduction of naturally occurring stenols had taken place over geological time. Stanols have also been identified in contemporary lacustrine sediments13–17. Based on the conversion of 14C-cholesterol into 14C-cholestanol under in situ incubation, Gaskell and Eglinton17,18 proposed that such stanols in young sediments originate from stenols by microbiological reduction after deposition.