Guo Lin, Yang Qiaoli, Wang Guangfei, Zhang Shumin, Liu Ming, Pan Xiaohong, Pescitelli Gennaro, Xie Zeping
School of Pharmacy, Binzhou Medical University, Yantai, China.
College of Life Sciences, Yantai University, Yantai, China.
Front Chem. 2021 Oct 12;9:756962. doi: 10.3389/fchem.2021.756962. eCollection 2021.
Angucyclines and angucyclinones represent the largest family of type II PKS-engineered natural products. Chemical analysis of a marine sp. KCB-132 yielded three new members, actetrophenone A (1) and actetrophenols A-B (2-3). Their structures were elucidated by NMR spectroscopy, X-ray crystallography and CD calculations. Actetrophenone A (1) is the first representative of a novel-type angucyclinone bearing a nonaromatic D-ring. Actetrophenol A (2) features a highly reduced and aromatized four-ring system, which is unprecedented for natural products. While ( )- and ( )-actetrophenol B (3) bear an unprecedented -acetyltryptamine-substituted tetraphene core skeleton, this is the first report of a pair of atropisomeric isomers in the angucyclinone family. Actetrophenol A (2) exhibits remarkable antibiotic activity, notably including potent activity to multiple resistant and with MIC values of 4 μg/ml, in contrast, the positive control antimicrobial agent penicillin was inactive up to 32 μg/ml.
安古环素类和安古环酮类是II型聚酮合酶工程天然产物中最大的家族。对一种海洋菌株KCB - 132进行化学分析，得到了三个新成员，即乙酰苯乙酮A（1）和乙酰苯酚A - B（2 - 3）。通过核磁共振光谱、X射线晶体学和圆二色性计算确定了它们的结构。乙酰苯乙酮A（1）是带有非芳香D环的新型安古环酮的首个代表。乙酰苯酚A（2）具有高度还原和芳构化的四环体系，这在天然产物中是前所未有的。而（ ）-和（ ）-乙酰苯酚B（3）带有前所未有的α-乙酰色胺取代的四苯核心骨架，这是安古环酮家族中一对阻转异构异构体的首次报道。乙酰苯酚A（2）表现出显著的抗菌活性，特别是对多种耐药菌具有强效活性，对 和 的最低抑菌浓度（MIC）值为4μg/ml，相比之下，阳性对照抗菌剂青霉素在高达32μg/ml时无活性。
