1662-21-1Relevant articles and documents
A comprehensive assessment of a new series of 5′,6′-difluorobenzotriazole-acrylonitrile derivatives as microtubule targeting agents (MTAs)
Bagella, Luigi,Bordoni, Valentina,Carta, Antonio,Ibba, Roberta,Lai, Michele,Piras, Sandra,Riu, Federico,Sanna, Luca,Scorciapino, M. Andrea,Sestito, Simona
, (2021)
Microtubules (MTs) are the principal target for drugs acting against mitosis. These compounds, called microtubule targeting agents (MTAs), cause a mitotic arrest during G2/M phase, subsequently inducing cell apoptosis. MTAs could be classified in two groups: microtubule stabilising agents (MSAs) and microtubule destabilising agents (MDAs). In this paper we present a new series of (E) (Z)-2-(5,6-difluoro-(1H)2H-benzo[d] [1,2,3]triazol-1(2)-yl)-3-(R)acrylonitrile (9a-j, 10e, 11a,b) and (E)-2-(1H-benzo[d] [1,2,3]triazol-1-yl)-3-(R)acrylonitrile derivatives (13d,j), which were recognised to act as MTAs agents. They were rationally designed, synthesised, characterised and subjected to different biological assessments. Computational docking was carried out in order to investigate the potential binding to the colchicine-binding site on tubulin. From this first prediction, the di-fluoro substitution seemed to be beneficial for the binding affinity with tubulin. The new fluorine derivatives, here presented, showed an improved antiproliferative activity when compared to the previously reported compounds. The biological evaluation included a preliminary antiproliferative screening on NCI60 cancer cells panel (1–10 μM). Compound 9a was selected as lead compound of the new series of derivatives. The in vitro XTT assay, flow cytometry analysis and immunostaining performed on HeLa cells treated with 9a showed a considerable antiproliferative effect, (IC50 = 3.2 μM), an increased number of cells in G2/M-phase, followed by an enhancement in cell division defects. Moreover, β-tubulin staining confirmed 9a as a MDA triggering tubulin disassembly, whereas colchicine-9a competition assay suggested that compound 9a compete with colchicine for the binding site on tubulin. Then, the co-administration of compound 9a and an extrusion pump inhibitor (EPI) was investigated: the association resulted beneficial for the antiproliferative activity and compound 9a showed to be client of extrusion pumps. Finally, structural superimposition of different colchicine binding site inhibitors (CBIs) in clinical trial and our MDA, provided an additional confirmation of the targeting to the predicted binding site. Physicochemical, pharmacokinetic and druglikeness predictions were also conducted and all the newly synthesised derivatives showed to be drug-like molecules.
Fluorinated Heterocycles: II. Synthesis of Quinoxaline 1,4-Dioxides
Kotovskaya,Charushin,Chupakhin,Kozhevnikova
, p. 369 - 374 (2007/10/03)
7-Amino-6-fluoroquinoxaline 1,4-dioxides have been synthesized by reaction of 5,6-difluorobenzofuroxan with enamines derived from cycloalkanones and with malononitrile. The transformation of 5,6-difluorobenzofuroxan into quinoxalin 1,4-dioxides in the pre
Hypoxia-Selective Agents Derived from Quinoxaline 1,4-Di-N-oxides
Monge, Antonio,Palop, Juan A.,Cerain, Adela Lopez de,Senador, Virginia,Martinez-Crespo, Francisko J.,et al.
, p. 1786 - 1792 (2007/10/02)
Hypoxic cells, which are a common feature of solid tumors, but not normal tissues, are resistant to both anticancer drugs and radiation therapy.Thus the identification of drugs with selective toxicity toward hypoxic cells is an important objective in anticancer chemotherapy.The benzotriazine di-N-oxide (SR 4233, Tirapazamine) has been shown to be an efficient and selective cytotoxin for hypoxic cells.Since the bioreductive activation of Tirapazamine is thought to be due to the presence of the 1,4-di-N-oxide moiety, a series of 3-aminoquinoxaline-2-carbonitrile 1,4-di-N-oxides with a range of electron-donating and -withdrawing substituents in the 6- and /or 7- positions has been synthesized and evaluated for toxicity to hypoxic cells.Electrochemical studies of the quinoxaline di-N-oxides and Tirapazamine showed that as the electron-withdrawing nature of the 6(7)-substituent increases, the reduction potential becomes more positive and the compound is more readily reduced.Apart from the unsubstituted 6a and the 6,7-dimethyl derivative 6c, the quinoxaline di-N-oxide have reduction potentials significantly more positive than Tirapazamine (Epc -0.90 V).The most potent cytotoxins to cells in culture were the 6,7-dichloro and 6,7-difluoro derivatives 6i and 6l, which were 30-fold more potent than Tirapazamine.The 6(7)-fluoro and 6(7)-chloro compounds, 6e and 6h, showed the greatest hypoxia selectivity.Four of the compounds, 6e, 6f, 6h and 6i, killed the inner cells of multicellular tumor spheroids in vitro.In vivo Balb/c mice tolerated a dose of these four compounds twice the size of that of Tirapazamine.This study demonstrates that quinoxaline 1,4-di-N-oxides could provide useful hypoxia-selective therapeutic agents.
