Macrocyclic alkaloids with a cyclopenta[b]fluorene ring system are a relatively young structural class of fungal metabolites, with the first members reported in 2013. Bioassay-guided fractionation of a Sarocladium sp. (fungal strain MSX6737) led to a series of both known and new members of this structural class (1–5), including the known embellicine A (1), three new embellicine analogues (2, 4, and 5), and a semisynthetic acetylated analogue (3). The structures were identified by examining both high-resolution electrospray ionization mass spectrometry data and one-dimensional and two-dimensional NMR spectra. The relative configurations of these molecules were established via ¹H–¹H coupling constants and nuclear Overhauser effect spectroscopy, while comparisons of the experimental electronic circular dichroism (ECD) spectra with the time-dependent density functional theory ECD calculations were utilized to assign their absolute configurations, which were in good agreement with the literature. These alkaloids (1–5) showed cytotoxic activity against a human breast cancer cell line (MDA-MB-231) that ranged from 0.4 to 4.8 μM. Compounds 1 and 5 were also cytotoxic against human ovarian (OVCAR3) and melanoma (MDA-MB-435) cancer cell lines.

中文翻译：

---

Embellicines CE：来自真菌 Sarocladium sp. 的具有环戊烷 [b] 芴环系统的大环生物碱。

具有环戊[b]芴环系统的大环生物碱是一种相对较新的真菌代谢物结构类别，第一批成员于2013年报道。（真菌菌株 MSX6737）导致该结构类别的一系列已知和新成员（1-5 ） ，包括已知的embellicine A（1）、三个新的 embellicine 类似物（2、4和5 ），以及一个半合成的乙酰化类似物 ( 3). 通过检查高分辨率电喷雾电离质谱数据和一维和二维核磁共振谱来鉴定结构。这些分子的相对构型是通过¹ H– ¹ H 耦合常数和核 Overhauser 效应光谱建立的，同时利用实验电子圆二色性 (ECD) 光谱与时间相关密度泛函理论 ECD 计算的比较来分配它们的绝对配置，这与文献非常一致。这些生物碱 ( 1 – 5 ) 对人乳腺癌细胞系 (MDA-MB-231) 显示出细胞毒活性，浓度范围为 0.4 至 4.8 μM。化合物1和5还对人卵巢 (OVCAR3) 和黑色素瘤 (MDA-MB-435) 癌细胞系具有细胞毒性。