A new diketopiperazine-like compound, designated protuboxepin K (1), was isolated together with the known structurally related protuboxepin A (2) from culture broth of the marine-derived fungal strain Aspergillus sp. BFM-0085 isolated from a sediment sample of Tokyo Bay. The structure of protuboxepin K was elucidated by spectroscopic data, including 1D and 2D NMR. Compounds 1 and 2 inhibited bone morphogenetic protein (BMP)-induced alkaline phosphatase activity with IC50 values of 4.7 and 25.2 μM, respectively, in mutant BMP receptor-carrying C2C12(R206H) cells.

中文翻译：

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海洋来源的曲霉菌产生的一种新的类二酮哌嗪类骨形态发生蛋白诱导的成骨细胞分化抑制剂。BFM-0085。

从海洋来源的真菌菌株曲霉菌的培养液中分离出一种新的类二酮哌嗪类化合物，称为protuboxepin K（1）和已知的与结构相关的protuboxepin A（2）。从东京湾的沉积物样本中分离出的BFM-0085。通过包括1D和2D NMR在内的光谱数据阐明了protuboxepin K的结构。在携带BMP受体的突变C2C12（R206H）细胞中，化合物1和2抑制骨形态发生蛋白（BMP）诱导的碱性磷酸酶活性，IC50值分别为4.7和25.2μM。