Natural Products Research Institute, College of Pharmacy, Seoul National University , San 56-1, Sillim, Gwanak, Seoul 151-742, Korea.
J Nat Prod. 2013 Sep 27;76(9):1679-85. doi: 10.1021/np400389c. Epub 2013 Sep 11.
Four new cytotoxic diterpenoid pseudodimers (2-5), along with a previously reported one, gukulenin A (1), were isolated from the marine sponge Phorbas gukhulensis collected off the coast of Gagu-do, Korea. These novel compounds, designated gukulenins C-F (2-5), were determined by extensive spectroscopic analyses to be pseudodimers of the gagunins, like gukulenin A. The termini of the tropolone-containing side chains in gukulenins C-E (2-4) were found to have diverse modifications involving acetamides or taurine, whereas gukulenin F (5) was formed from 1 by the ring-opening of a cyclic hemiketal. The relative and absolute configurations were assigned by Murata's and modified Snatzke's methods using a HETLOC experiment and a CD measurement of a dimolybdenum complex, respectively. All of these compounds exhibited significant cytotoxicity against the K562 and A549 cell lines.
从韩国加古岛海域采集的海绵 Phorbas gukhulensis 中分离得到了四个新的细胞毒性二萜假二聚体（2-5），以及一个先前报道的化合物 gukulenin A（1）。这些新化合物，被命名为 gukulenins C-F（2-5），通过广泛的光谱分析确定为 gagunins 的假二聚体，类似于 gukulenin A。在 gukulenins C-E（2-4）中，含有三酮的侧链的末端具有不同的修饰，涉及乙酰氨基酚或牛磺酸，而 gukulenin F（5）则是通过环状半缩醛的开环形成的。通过 Murata 法和改良的 Snatzke 法，使用 HETLOC 实验和二钼配合物的 CD 测量，分别确定了相对和绝对构型。所有这些化合物对 K562 和 A549 细胞系均表现出显著的细胞毒性。
