Institute of Organic Chemistry, Technische Universität Braunschweig , Hagenring 30, 38106 Braunschweig, Germany.
J Nat Prod. 2017 Sep 22;80(9):2572-2582. doi: 10.1021/acs.jnatprod.7b00366. Epub 2017 Aug 24.
Macrolides are a relatively common structural motif prevalent in Nature. However, the structures of these large ring lactones have been relatively difficult to elucidate via NMR spectroscopy due to the minute amounts of compounds that are sometimes obtainable from natural sources. Thus, GC-MS analysis of individual macrolactones has become the method of choice for the structural identification of these compounds. Here we discuss the mass spectrometric behavior of aliphatic macrolides, evaluating spectra from numerous compounds of various ring size, including derivatives containing methyl branches as well as double bonds. The specific fragmentation of these macrolactones under electron impact conditions allows for the development of a general rule set aimed at the identification of similar compounds by mass spectrometry. In addition, the mass spectra of dimethyl disulfide adducts of unsaturated macrolides are discussed. The mass spectra of almost 50 macrolides are presented.
大环内酯是自然界中一种相对常见的结构基序。然而，由于有时从天然来源获得的化合物数量很少，通过 NMR 光谱法阐明这些大环内酯的结构相对困难。因此，对单个大环内酯的 GC-MS 分析已成为这些化合物结构鉴定的首选方法。在这里，我们讨论了脂肪族大环内酯的质谱行为，评估了来自各种环大小的许多化合物的光谱，包括含有甲基支链和双键的衍生物。在电子冲击条件下，这些大环内酯的特定片段化允许制定一套通用规则，旨在通过质谱法鉴定类似的化合物。此外，还讨论了不饱和大环内酯的二甲基二硫加合物的质谱。给出了近 50 种大环内酯的质谱。
