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Updated: Feb 10, 2026

Simple and Fast Rolling Circle Amplification-Based Detection of Topoisomerase 1 Activity in Crude Biological Samples
Published on: December 2, 2022
Precursor-Directed Generation of Indolocarbazoles with Topoisomerase IIα Inhibitory Activity
Cong Wang1,2, Adeep Monger3, Liping Wang4
1Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China. wangcong123206@163.com.
Abstract:
One new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3'-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-l-tryptophan. Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 potently induced apoptosis of gastric cancer cells by inhibiting topoisomerase IIα enzyme activity and reducing the expression of antiapoptosis protein level. Compound 3 displayed moderate cytotoxicity against the A549 and MCF-7 cell lines with IC50 values of 1.2 ± 0.05 μM, 1.6 ± 0.09 μM, respectively.
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