- Synthesis of quinone imine and sulphur-containing compounds with antitumor and trypanocidal activities: Redox and biological implications
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Ortho-Quinones represent a special class of redox active compounds associated with a spectrum of pronounced biological activities, including selective cytotoxicity and antimicrobial actions. The modification of the quinone ring by simple nitrogen and sulphur substitutions leads to several new classes of compounds with their own, distinct redox behaviour and equally distinct activities against cancer cell lines and Trypanosoma cruzi. Some of the compounds investigated show activity against T. cruzi at concentrations of 24.3 and 65.6 μM with a selectivity index of around 1. These results demonstrate that simple chemical modifications on the ortho-quinone ring system, in particular, by heteroatoms such as nitrogen and sulphur, transform these simple redox molecules into powerful cytotoxic agents with considerable "potential", not only in synthesis and electrochemistry, but also, in a broader sense, in health sciences. This journal is
- Almeida, Renata G.,Barbosa, Juliana M. C.,De Carvalho, Guilherme G. C.,De Castro, Solange L.,De Simone, Carlos A.,Goulart, Marilia O. F.,Kharma, Ammar,Paier, Carlos R. K.,Pessoa, Claudia,Pinheiro, Daniel P.,Da Silva Júnior, Eufranio N.,Rosa, Luísa G.,Valen?a, Wagner O.
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p. 1145 - 1160
(2020/11/03)
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- Selective Inhibitors of Human Liver Carboxylesterase Based on a β-Lapachone Scaffold: Novel Reagents for Reaction Profiling
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Carboxylesterases (CEs) are ubiquitous enzymes that are responsible for the metabolism of xenobiotics, including drugs such as irinotecan and oseltamivir. Inhibition of CEs significantly modulates the efficacy of such agents. We report here that β-lapachone is a potent, reversible CE inhibitor with Ki values in the nanomolar range. A series of amino and phenoxy analogues have been synthesized, and although the former are very poor inhibitors, the latter compounds are highly effective in modulating CE activity. Our data demonstrate that tautomerism of the amino derivatives to the imino forms likely accounts for their loss in biological activity. A series of N-methylated amino derivatives, which are unable to undergo such tautomerism, were equal in potency to the phenoxy analogues and demonstrated selectivity for the liver enzyme hCE1. These specific inhibitors, which are active in cell culture models, will be exceptionally useful reagents for reaction profiling of esterified drugs in complex biological samples.
- Hatfield, M. Jason,Chen, Jingwen,Fratt, Ellie M.,Chi, Liying,Bollinger, John C.,Binder, Randall J.,Bowling, John,Hyatt, Janice L.,Scarborough, Jerrod,Jeffries, Cynthia,Potter, Philip M.
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supporting information
p. 1568 - 1579
(2017/03/08)
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- Synthesis and optical properties of acidochromic amine-substituted benzo[a]phenazines
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A new series of alkylamine- or arylamine-substituted benzo[a]phenazines have been synthesized from 1,2-naphthoquinones by employing simple sequential Michael-type addition with a variety of primary and secondary amines and the condensation reaction of the resulting amine-substituted 1,2-naphthoquinones with o-phenylenediamine. They exhibited absorption peaks originating from the charge transfer transition between the amine and pyrazine segments and benzo[a]phenazine localized π-π* transitions. Although the absorption spectra of the dyes were not significantly influenced by the nature of the solvents, addition of TFA led to a prominent red-shift in the absorption spectra owing to the protonation at the quinoxaline segment which enhanced the electron-accepting ability. The qualitative trends observed in the optical properties and acidochromism were supported by density functional theoretical computations. The dyes displayed positive solvatochromism in the emission spectra suggestive of a more polar excited state. The dyes were also characterized by a quasi-reversible reduction couple originating from the pyrazine segment which underwent shifts corresponding to electron-donating strength of the amine segment.
- Singh, Prachi,Baheti, Abhishek,Thomas, K. R. Justin
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supporting information; experimental part
p. 6134 - 6145
(2011/10/09)
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- HEAT SHOCK PROTEIN 90 INHIBITORS, METHODS OF PREPARING SAME, AND METHODS FOR THEIR USE
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Novel classes of molecular chaperone Heat shock protein 90 (Hsp90) inhibitors are disclosed. These compounds are useful in treating and preventing cancer and other Hsp90-related diseases and conditions, such as inflammation and neurodegenerative disorders. Methods of treating and preventing cancer and other Hsp90 related diseases and conditions are disclosed that include administering to the subject a therapeutically effective amount of an Hsp90 inhibitor. Methods of preparing the novel Hsp90 inhibitors are also provided.
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Page/Page column 13
(2010/04/28)
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