Chemical investigation of the marine sponge Ircinia oros yielded four linear furanosesterterpenoids, including the known metabolites ircinin-1 (1) and ircinin-2 (2) and two new compounds, ircinialactam E (3) and ircinialactam F (4). Their chemical structures were elucidated by using a combination of [α]_D, NMR, HRMS, and FT-IR spectroscopy. The absolute configuration of C-18 in compounds 1–3 was identified as R by electronic circular dichroism (ECD) spectroscopy coupled with time-dependent density functional theory calculations. Compounds 1–4 showed moderate leishmanicidal, trypanocidal, and antiplasmodial activities (IC₅₀ values 28–130 μM). This is the second report of rare glycinyl lactam derivatives 3 and 4 from the genus Ircinia.

中文翻译：

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海洋海绵Ircinia oros的抗原生动物线性呋喃酯类萜

海洋海绵Ircinia oros的化学研究产生了四种线性呋喃酯类萜，包括已知的代谢产物ircinin-1（1）和ircinin-2（2）以及两种新化合物ircinialactam E（3）和ircinialactam F（4）。通过结合使用[α] _D，NMR，HRMS和FT-IR光谱阐明了它们的化学结构。化合物C-18的绝对构型1 - 3被鉴定为[R由电子圆二色性（ECD）光谱加上时间依赖密度泛函理论计算。化合物1 - 4表现出中等程度的杀菌作用，锥虫杀菌作用和抗疟原虫作用（IC ₅₀值为28–130μM）。这是来自Ircinia属的罕见的甘氨酰内酰胺衍生物3和4的第二次报告。