Gutiérrez-Cepeda Adrián, Daranas Antonio Hernández, Fernández José J, Norte Manuel, Souto María L
University Institute of Bio-Organic Chemistry "Antonio González", Center for Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, Astrofísico Francisco Sánchez 2, La Laguna 38206, Tenerife, Spain.
Mar Drugs. 2014 Jul 1;12(7):4031-44. doi: 10.3390/md12074031.
Five-membered rings are of particular interest, due to their presence in some of the most common molecules in chemistry and biology. Despite their apparent simplicity, the structural resolution of these rings is complex, due to their inherent conformational flexibility. Here, we describe an application of a recently reported simple and efficient NMR protocol based on the measurement of spin-spin coupling constants to achieve the challenging relative configurations of five new halogenated C15 tetrahydrofuranyl-acetogenins, marilzafurollenes A-D (1-4) and 12-acetoxy-marilzafurenyne (5), isolated from the red alga, Laurencia marilzae. Although DFT chemical shift calculations were used to connect remote stereocenters, the NMR-based approach seems advantageous over computational techniques in this context, as the presence of halogens may interfere with reliable calculations.
五元环特别引人关注，因为它们存在于化学和生物学中一些最常见的分子中。尽管它们看似简单，但由于其固有的构象灵活性，这些环的结构解析很复杂。在此，我们描述了一种最近报道的基于测量自旋-自旋耦合常数的简单高效核磁共振方法的应用，以确定从红藻 Laurencia marilzae 中分离出的五个新的卤代 C15 四氢呋喃基产乙酸素，即 marilzafurollenes A-D（1-4）和 12-乙酰氧基-marilzafurenyne（5）的具有挑战性的相对构型。尽管使用了密度泛函理论（DFT）化学位移计算来连接远程立体中心，但在这种情况下，基于核磁共振的方法似乎比计算技术更具优势，因为卤素的存在可能会干扰可靠的计算。
