Related Experiment Video
Updated: May 5, 2026

Functionalized Spirocyclic Heterocycle Synthesis and Cytotoxicity Assay
Published on: February 9, 2021
Structural optimization of benzophenanthridinone and benzophenanthridine Tyrosyl-DNA phosphodiesterase 1 inhibitors
De-Xuan Hu1, Yue-Wen Li2, Ao Chen2
1School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China; State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China; Chengdu Medical College, Chengdu, 610500, China.
Abstract:
Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a potential radiotherapeutic target for cancer treatment. Herein, two series of analogues, benzophenanthridinone derivatives and benzophenanthridine derivatives, were designed and synthesized based on the reported TDP1 inhibitor NTD119B showing strong radiosensitization in vitro and in vivo. The structural modification gave seventeen analogues with stronger TDP1 inhibitory activity than NTD119B (IC50 = 6.9 μM). B11 showed the most potent TDP1 inhibition (IC50 = 1.2 ± 0.7 μM), 5.8-fold greater than NTD119B. Colony formation assays showed four TDP1 inhibitors A6, A26, B1, B7 showing stronger radiosensitizing activity than NTD119B in HCT116 cells. Further studies demonstrate that A6 targets TDP1 in cells and suppresses NHEJ repair activity, enhancing ionizing radiation-induced DNA damage resulting in a strong radiosensitizing activity both in HCT116 cells and xenografts animal model. The structure-activity relationship for TDP1 inhibition is also analyzed.
More Related Videos
07:20Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
05:32Author Spotlight: Characterizing DNA G-Quadruplex by Bis-3-Chloropiperidine Based Chemical Mapping
Published on: May 12, 2023
Related Concept Videos
Inhibitors of Bacterial DNA Synthesis
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Directing and Steric Effects in Disubstituted Benzene Derivatives
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H