Abstract | BACKGROUND: Compounds bearing two independent redox centers are considered bis-bioreductive agents and usually demonstrate increased hypoxic selectivity with exposure time due to different requirements for reduction of each center. We have synthesized a novel 2-[3-(2-nitro-1-imidazolyl)propylamino]-3-chloro-1,4- naphthoquinone (NLNQ-1), through Michael addition. NLNQ-1, which combines a naphthoquinone (with a relatively high one electron reduction potential) with a 2-nitroimidazole (with a relatively low one electron reduction potential), could perform as a more potent hypoxia-selective cytotoxin and radiosensitizer. MATERIALS AND METHODS: NLNQ-1 was evaluated in V79 cells under hypoxic/normoxic conditions, alone or with radiation, by using the clonogenic assay. RESULTS: Clearly NLNQ-1 was a more potent cytotoxin than the 2-alkylsulfonyloxy-naphthoquinones (VH-compounds), developed previously in our lab, demonstrating hypoxic and aerobic IC50 values at microM rather than mM concentrations. As a radiosensitizer of hypoxic cells, NLNQ-1 was superior to the best bis-nitroimidazolic compound, NNB (which combines a 2- nitroimidazole with a 5- nitroimidazole), demonstrating a C1.6 value of 25.4 microM (ca. 25 fold lower than that of NNB), whereas its in vitro therapeutic index (IC50A/C1.6) ranged from 5.3-13.2. CONCLUSION: NLNQ-1 could be used as a novel scaffold for bis-bioreductive agents that can be properly modified for further optimization of their hypoxia-selective toxicity and radiosensitization properties.
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Authors | Maria V Papadopoulou, William D Bloomer |
Journal | In vivo (Athens, Greece)
(In Vivo)
2008 May-Jun
Vol. 22
Issue 3
Pg. 285-8
ISSN: 0258-851X [Print] Greece |
PMID | 18610737
(Publication Type: Journal Article)
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Chemical References |
- 2-(3-(2-nitro-1-imidazolyl)propylamino)-3-chloro-1,4-naphthoquinone
- Imidazoles
- Naphthoquinones
- Radiation-Sensitizing Agents
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Topics |
- Animals
- Cell Hypoxia
(drug effects, radiation effects)
- Cell Line
- Cell Survival
(drug effects, radiation effects)
- Cricetinae
- Imidazoles
(chemistry, toxicity)
- Molecular Structure
- Naphthoquinones
(chemistry, toxicity)
- Radiation-Sensitizing Agents
(chemistry, toxicity)
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