Quinocidin, a Cytotoxic Antibiotic with an Unusual 3,4-Dihydroquinolizinium Ring and Michael Acceptor Reactivity toward Thiols
作者:Yu Nakagawa、Yuki Sawaki、Takahiro Kimura、Tomohiko Tomura、Yasuhiro Igarashi、Makoto Ojika
DOI:10.1002/chem.201704729
日期:2017.12.19
Actinomadura sp. TP‐A0019 led to the isolation of quinocidin (1), a cytotoxic antibiotic with an unusual 3,4‐dihydroquinolizinium ring. The structural assignment was made on the basis of high‐field NMR experiments and chemical synthesis. Comparison of the spectral properties of 1 with those of its synthetic counterparts revealed that 1 is a racemic mixture of two enantiomers, which showed similar cytotoxicity
Actinomadura sp。的培养液的细胞毒性引导分级分离。TP-A0019导致喹诺丁(1)分离,喹诺丁是一种具有异常3,4-二氢喹啉鎓环的细胞毒性抗生素。在高场NMR实验和化学合成的基础上进行了结构分配。将1与合成对映体的光谱性质进行比较后发现,1是两种对映异构体的外消旋混合物,对HeLa-S3细胞显示出相似的细胞毒性。亲核试剂俘获的实验表明,1捕获的2-巯基乙醇和Ñ乙酰基升-半胱氨酸通过迈克尔加成反应,但对2-氨基乙醇和乙醇酸呈惰性。值得注意的是,在室温下,在中性水性介质中,向硫醇中添加1顺利进行。鉴于硫醇的捕获能力和异常的结构,1提供了一种独特的支架,用于设计药物前导物和蛋白质标记探针。