Denigrins and Dactylpyrroles, Arylpyrrole Alkaloids from a <i>Dactylia</i> sp. Marine Sponge

Seven new arylpyrrole alkaloids (1–7), along with four known compounds, were isolated from an extract of a Dactylia sp. nov. marine sponge, and their structures were elucidated by interpretation of NMR and MS spectroscopic data. Denigrins D–G (1–4) have highly substituted pyrrole or pyrrolone rings in their core structures, while dactylpyrroles A–C (5–7) have tricyclic phenanthrene cores. Due to the proton-deficient nature of these scaffolds, key heteronuclear correlations from 1H–15N HMBC and LR-HSQMBC NMR experiments were used in the structure assignment of denigrin D (1). Dictyodendrin F (8), a previously described co-metabolite, inhibited transcription driven by the oncogenic PAX3-FOXO1 fusion gene with an IC50 value of 13 μM.本研究从一株新种指海绵（Dactylia sp. nov.）的提取物中分离得到7个全新芳基吡咯类生物碱（1~7）及4个已知化合物，并通过核磁共振波谱（NMR）与质谱（MS）数据解析阐明了其化学结构。其中，德尼格林类生物碱D~G（1~4）的核心骨架带有高度取代的吡咯或吡咯酮环，而指海绵吡咯类生物碱A~C（5~7）则具有三环菲类母核。鉴于这类骨架存在缺质子特性，研究人员借助1H–15N异核多键相关谱（HMBC）与长程异核单量子多键相关谱（LR-HSQMBC）NMR实验获得的关键异核相关数据，完成了德尼格林D（1）的结构解析。此前已报道的共代谢产物双茎藻素F（Dictyodendrin F，8）可抑制致癌性PAX3-FOXO1融合基因驱动的转录过程，其半数抑制浓度（IC50）为13 μM。