Abstract:
Natural product dimers have intriguing structural features and often have remarkable pharmacological activities. We report here two uncommon marine gorgonian-derived symmetric dimers, weizhouochrones A (1) and B (2), with indenone-derived monomers, that were isolated from the coral Anthogorgia ochracea collected from the South China Sea. These dimers are difficult targets for structure elucidation that solely relies upon conventional NMR data such as NOEs and J-couplings. Here, to explore the application of emerging methods on the structure elucidation of challenging molecules, we explored a number of different anisotropic and computational NMR approaches. The measurements of anisotropic NMR parameters of weizhouochrone A, including residual dipolar couplings (RDCs) and residual chemical shift anisotropy (RCSA), allowed us to successfully determine the planar structure and its relative configuration. This result was corroborated by a computational NMR analysis based on DP4+ probability and computer-assisted 3D structure elucidation (CASE-3D).
摘要:
天然产物二聚体具有有趣的结构特征,并且通常具有显着的药理活性。我们在这里报告了两个不常见的海洋gorgonian衍生的对称二聚体,WeizhouochronesA(1)和B(2),茚酮衍生的单体,它们是从南中国海收集的珊瑚Anthogorgiaochracea中分离出来的。这些二聚体是仅依赖于常规NMR数据如NOE和J-偶联的结构阐明的困难目标。这里,探索新兴方法在具有挑战性的分子结构阐明中的应用,我们探索了许多不同的各向异性和计算NMR方法。WeizhouochroneA的各向异性NMR参数的测量,包括残余偶极耦合(RDC)和残余化学位移各向异性(RCSA),使我们能够成功地确定平面结构及其相对配置。该结果通过基于DP4+概率和计算机辅助3D结构阐明(CASE-3D)的计算NMR分析得到证实。