1016-90-6

Upstream product

• 67692-91-5 3-chloro-1,2,4-benzotriazine 1-oxide 
• 97-00-7 1-chloro-2,4-dinitro-benzene 
• 619-16-9 1-chloro-2,5-dinitrobenzene 
• 5424-06-6 3-amino-1,2,4-benzotriazine 1-oxide 
• 27446-08-8 3-oxo-3,4-dihydrobenzo-1,2,4-triazine 1-oxide 

Relevant academic research and scientific papers

Radical properties governing the hypoxia-selective cytotoxicity of antitumor 3-amino-1,2,4-benzotriazine 1,4-dioxidest

Revealing the free radical mechanism by which the anticancer drug tirapazamine (3-amino-1,2,4-benzotriazine 1,4-dioxide) induces hypoxia-selective cytotoxicity, is seen as a way forward to develop clinically useful bioreductive drugs against chemo- and radiation-resistant hypoxic tumor cells. Our previous studies point to the formation of an active benzotriazinyl radical following the one-electron reduction of tirapazamine and its elimination of water from the initial reduction intermediate, and have suggested that this species is a cytotoxin. In this paper we have used pulse radiolysis to measure the one-electron reduction potentials of the benzotriazinyl radicals E(B ?,H+/B) of 30 analogues of tirapazamine as well as the one-electron reduction potentials of their two-electron reduced metabolites, benzotriazine 1-oxides E(B/B?-. The redox dependencies of the back-oxidation of the one-electron reduced benzotriazine 1,4-dioxides by oxygen, their radical prototropic properties and water elimination reactions were found to be tracked in the main by the one-electron reduction potentials of the benzotriazine 1,4-dioxides E(A/A?-). Multiple regression analysis of published aerobic and hypoxic clonogenic cytotoxicity data for the SCCVII murine tumor cell line with the physical chemistry parameters measured in this study, revealed that hypoxic cytotoxicity is dependent on E(B ?, H-/B) thus providing strong evidence that the benzotriazinyl radicals are the active cytotoxic species in hypoxia, while aerobic cytotoxicity is dependent on E(B/B?-). It is concluded that maximizing the differential ratio between these two controlling parameters, in combination with necessary pharmacological aspects, will lead to more efficacious anticancer bioreductive drugs. The Royal Society of Chemistry 2005.

Benzoazine mono-N-oxides and benzoazine 1,4 dioxides and compositions therefrom for the therapeutic use in cancer treatments

The present invention relates to a synergetistic composition comprising one or more benzoazine-mono-N-oxides, and one or more benzoazine 1,4 dioxides for use in cancer therapy. The invention also provides a range of novel 1,2,4 benzoazine-mono-N-oxides and related analogues. These can be used as potentiators of the cytotoxicity of existing anticancer drugs and therapies for cancer treatment.

Benzoazine mono-N-oxides and benzoazine 1,4 dioxides and compositions therefrom for the therapeutic use in cancer treatments

The present invention relates to a synergetistic composition comprising one or more benzoazine-mono-N-oxides, and one or more benzoazine 1,4 dioxides for use in cancer therapy. The invention also provides a range of novel 1,2,4 benzoazine-mono-N-oxides and related analogues. These can be used as potentiators of the cytotoxicity of existing anticancer drugs and therapies for cancer treatment.

Structure-activity relationships of 1,2,4-benzotriazine 1,4-dioxides as hypoxia-selective analogues of tirapazamine

Tirapazamine (TPZ, 1,2,4-benzotriazin-3-amine 1,4-dioxide) is a bioreductive hypoxic cytotoxin currently in Phase II/III clinical trials in combination with radiotherapy and with cisplatin-based chemotherapy. As part of a program to develop TPZ analogues with improved solubility/potency and therapeutic indices, we synthesized 34 1,2,4-benzotriazin-3-amine 1,4-dioxides (BTO) to examine structure-activity relationships (SAR) for ring substitution. The electronic, hydrophobic, and steric parameters of substituents at the 5-, 6-, 7-, and 8-positions were systematically varied, and the aqueous solubility and one-electron reduction potentials [E(1)] of the analogues were determined. For each compound, we determined cell killing of mouse SCCVII tumor cells in vitro under aerobic and hypoxic conditions by clonogenic survival and determined their relative hypoxic toxicity (RHT; relative to TPZ) and hypoxic cytotoxicity ratio (HCR). A subset of compounds was independently evaluated using a 96-well SRB proliferation assay, the data from which correlated well with that derived by the clonogenic endpoint. Most substituents, except 5- and 8-dimethylamino and 8-diethylamino, gave analogues less soluble than TPZ. E(1) values ranged from -240 mV through -670 mV (with TPZ having a value of -456 mV) and correlated well with the electronic parameter σ for substituents at the 5-, 6-, 7-, and 8-positions. Aerobic cytotoxic potency showed a strong positive correlation with E(1) (i.e., electron-withdrawing substituents increased aerobic toxicity). Hypoxic cytotoxicity also generally increased with increasing E(1), with a maximum (RHT up to 3.9-fold) seen in halo- and trifluoromethyl-substituted BTO derivatives having E(1) between ca. -370 to -400 mV. Analogues with high HCRs (>50) all had E(1)s in the range -450 to -510 mV (weakly electron-donating substituents) with the exception of the 8-CF3 analogue, which had an HCR of 112 against SCCVII despite a high E(1) of -372 mV). The results suggest that ring-A substituents in BTO analogues can be used to predictably vary one-electron reduction potentials and also provide a much better definition than previously of the optimum range of these reduction potentials for a desirable biological activity profile (high HCR, RHT, and solubility).