(Table 1) Relative abundances of biphytanediols and biphytanes in IODP Site 315-C0001

The distribution of acyclic and cyclic biphytanediols, the putative breakdown products of glycerol dialkyl glycerol tetraethers (GDGTs), was investigated for recent marine sediments from Nankai Trough, offshore Kii Peninsula. The most abundant diol is tricyclic biphytanediol, whose relative abundance is in the range 32–46%. Its carbon skeleton, with two cyclopentane rings and one cyclohexane ring, is the same as would be expected via a crenarchaeol origin. Based on the structure of crenarchaeol, the tricyclic biphytanediol is considered to be derived not only from crenarchaeol but also from other unknown sources. The ring distributions of the biphytanediols are different from those of the biphytanes obtained from intact polar lipids by way of chemical treatment, suggesting that biphytanediols are not solely the diagenetic products of in situ GDGTs.

针对纪伊半岛近海南海海槽的现代海洋沉积物，研究了无环和环型双植烷二醇（biphytanediols）的分布特征——此类物质为甘油二烷基甘油四醚（glycerol dialkyl glycerol tetraethers, GDGTs）的推定降解产物。丰度最高的二醇为三环双植烷二醇，其相对丰度介于32%至46%之间。该物质的碳骨架包含两个环戊烷环与一个环己烷环，与源自克劳氏古菌醇（crenarchaeol）的预期结构一致。基于克劳氏古菌醇的分子结构，三环双植烷二醇被认为不仅源自克劳氏古菌醇，还存在其他未知来源。双植烷二醇的环系分布与经化学处理从完整极性脂中提取的植烷（biphytanes）的环系分布存在差异，这表明双植烷二醇并非仅为原位GDGTs的成岩降解产物。