A new macrolide, enigmazole C (1), and two additional analogues, enigmazoles E (2) and D (3), were obtained from a new species of the Homophymia genus as part of an ongoing discovery program at PharmaMar to study cytotoxic substances from marine sources. The structures were fully characterized by cumulative analyses of NMR, IR, and MS spectra, along with density functional theory computational calculations. All three of the new compounds feature an unusual 2,3-dihydro-4H-pyran-4-one moiety, but only enigmazoles C (1) and D (3) showed cytotoxic activity in the micromolar range against A-549 (lung), HT-29 (colon), MDA-MB-231 (breast), and PSN-1 (pancreas) tumor cells.

中文翻译：

---

Enigmazole C：一种来自同种海绵新种的细胞毒性大环内酯及其开环衍生物

作为 PharmaMar正在进行的研究细胞毒性物质的发现计划的一部分，从Homophymia属的一个新物种中获得了一种新的大环内酯类 enigmazole C ( 1 ) 和另外两种类似物 enigmazoles E ( 2 ) 和 D ( 3 )海洋资源。这些结构通过 NMR、IR 和 MS 光谱的累积分析以及密度泛函理论计算计算得到了充分的表征。所有这三种新化合物都具有不寻常的 2,3-dihydro-4 H -pyran-4-one 部分，但只有 enigmazoles C ( 1 ) 和 D ( 3) 在微摩尔范围内对 A-549（肺）、HT-29（结肠）、MDA-MB-231（乳腺）和 PSN-1（胰腺）肿瘤细胞显示出细胞毒活性。