Medicinal Chemistry Department, PharmaMar S. A. , Pol. Ind. La Mina Norte, Avenida de los Reyes 1, 28770, Colmenar Viejo (Madrid), Spain.
Departamento de Química Fundamental, Facultade de Ciencias e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña , 15071 A Coruña, Spain.
J Nat Prod. 2017 Mar 24;80(3):713-719. doi: 10.1021/acs.jnatprod.7b00046. Epub 2017 Mar 3.
Two new xenicanes, named protoxenicins A (1) and B (2), were isolated from an organic extract of the soft coral Protodendron repens, collected off the coast of Okuza (Tanzania), being the first chemical study of an organism belonging to this genus. Their planar structures were determined by 1D and 2D NMR and HRESIMS techniques, while the relative configurations were elucidated by comparison of their chemical shifts and coupling constants with the literature values of their congeners, as well as by ROESY experiments, chemical derivatization, and molecular mechanics calculations. This is the first report of a xenicin acylated with a long saturated fatty acid. Furthermore, the absolute configuration of the stereogenic centers of the cyclononane ring and at C-1 in 1 was determined by Mosher's method. Protoxenicin B (2) is present in solution as a mixture of two conformers in a 2:1 ratio deduced by H NMR. Both xenicanes display significant cytotoxic activity against a panel of different tumor cell lines.
从坦桑尼亚 Okuza 海域采集的软珊瑚 Protodendron repens 的有机提取物中分离得到了两种新的 xenicanes，分别命名为 protoxenicins A (1) 和 B (2)，这是对该属生物的首次化学研究。它们的平面结构通过 1D 和 2D NMR 和 HRESIMS 技术确定，而相对构型则通过与同系物的文献值比较其化学位移和偶合常数、ROESY 实验、化学衍生化和分子力学计算来阐明。这是首次报道 xenicin 被长饱和脂肪酸酰化。此外，通过 Mosher 法确定了环壬烷环和 1 位手性中心的绝对构型。在溶液中，protoxenicin B (2) 以 2:1 的比例存在两种构象混合物，这是由 1 H NMR 推断得出的。这两种 xenicanes 对不同肿瘤细胞系的细胞均显示出显著的细胞毒性。
