Caldorazole (1) was isolated from the marine cyanobacterium Caldora sp. collected on Ishigaki Island, Okinawa, Japan. Its structure was determined to be a new polyketide that contained two thiazole rings and an O-methylenolpyruvamide moiety. Caldorazole (1) showed strong cytotoxicity toward tumor cells that had been seeded at a high density. Cell death induced by 1 in HeLa and A431 cells was also observed only in the presence of the glycolysis blocker 2-deoxy-d-glucose (2DG). Co-treatment with 1 and 2DG remarkably decreased ATP levels in these cells. Furthermore, 1 selectively inhibited complex I in the mitochondrial respiratory chain. Thus, 1 was demonstrated to exert cytotoxicity toward human tumor cells by blocking mitochondrial respiration.

中文翻译：

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卡多拉唑的分离，一种在葡萄糖限制条件下具有选择性细胞毒性的含噻唑聚酮化合物

Caldorazole ( 1 ) 从海洋蓝藻Caldora sp. 中分离得到。采集于日本冲绳岛石垣岛。其结构被确定为含有两个噻唑环和一个O-亚甲基丙酮酰胺部分的新聚酮化合物。Caldorazole ( 1 ) 对高密度接种的肿瘤细胞表现出很强的细胞毒性。仅在糖酵解阻滞剂 2-脱氧-d-葡萄糖 (2DG) 存在下也观察到由​​ 1 在 HeLa 和 A431 细胞中诱导的细胞死亡。与1和 2DG 共同处理显着降低了这些细胞中的 ATP 水平。此外，1选择性抑制线粒体呼吸链中的复合物 I。因此，1被证明通过阻断线粒体呼吸对人类肿瘤细胞产生细胞毒性。