scholarly journals Oxidation of Glyoxylic Acid by Cerium(IV):  Oxygen-Induced Enhancement of the Primary Radical Concentration

1996 ◽  
Vol 100 (30) ◽  
pp. 12342-12348 ◽  
Author(s):  
Bettina Neumann ◽  
Oliver Steinbock ◽  
Stefan C. Müller ◽  
Nar S. Dalal
2003 ◽  
Vol 28 (1) ◽  
pp. 105-118 ◽  
Author(s):  
Dimitri A. Svistunenko ◽  
Brandon J. Reeder ◽  
Michael T. Wilson ◽  
Chris E. Cooper

Three EPR signals from individual free radical species have been identified in the EPR spectra of horse heart metmyoglobin (HH metMb) mixed with hydrogen peroxide (H2O2). The peroxyl radical EPR signal was assigned to the Trp14-OO• radical, the seven component signal – to the Tyr103• radical and the singlet EPR signal was assigned to the Tyr146• radical. Apo-Mb (haem free HH Mb) added in various concentrations to the native metMb prior to H2O2 addition affected the yields of the three types of radicals. As the concentrations of metMb and H2O2 were kept constant, the yield of the primary radical formed is the same in all experiments, H2O2 being unable to produce any radical in the reaction with a haem free protein. Nevertheless, the addition of apo-Mb resulted in an increase of the Tyr146• radical concentration and in a quantitatively similar decrease of the Tyr103• radical concentration. These changes were dependent on the concentration of the added apo-Mb. Thus we show that a radical transfer Tyr103• → Tyr146• occurs and that this reaction is protein concentration dependent. The question whether this radical transfer is inter- or intra-molecular is discussed. A similarity is drawn between the system studied and the sperm whale metMb/H2O2 system, for which the radical transfer Tyr103• → Tyr151• has been previously suggested.


2020 ◽  
Vol 19 (16) ◽  
pp. 2001-2009 ◽  
Author(s):  
Malavattu G. Prasad ◽  
C. Vijaya Lakshmi ◽  
Naresh K. Katari ◽  
Sreekantha B. Jonnalagadda ◽  
Manojit Pal

Background: Compounds containing the quinazoline-4(3H)-one framework constitute an important class of fused N-heterocycles that are found in more than 200 naturally occurring alkaloids. These compounds also show a diverse range of pharmacological activities including antitumor properties. This prompted us to explore a series of quinazolin-4-(3H)-one derivatives having no substituent at C-2 as potential cytotoxic agents. Objective: The objective of this study was to synthesize and evaluate 3-substituted quinazolin-4(3H)-one derivatives for their potential cytotoxic properties. Methods: A convenient method has been developed for the rapid synthesis of this class of compounds under a mild and non-hazardous reaction condition in good yields. The methodology involved a three-component reaction employing isatoic anhydride, amines and glyoxylic acid as reactants in the presence of lemon juice in PEG- 400 at room temperature (25-30ºC) under ultrasound irradiation. All the synthesized compounds were screened via an MTT assay for their potential cytotoxic properties in vitro using the cancerous cell lines e.g. A549, A2780, HepG2, K562, MCF-7 and HCT-116 and a non-cancerous HEK293 cell line. Results: Several compounds such as 3a, 3b, 3d, 3e and 3f showed promising growth inhibition against these cancer cell lines but no significant effects on HEK293 cell line. The IC50 values of these compounds were comparable to doxorubicin whereas 3f significantly induced apoptosis in MCF-7 cells that also was comparable to doxorubicin. Conclusion: An ultrasound-assisted MCR facilitated by lemon juice has been developed to synthesize 3- substituted quinazolin-4(3H)-one derivatives that could act as potential anticancer agents.


1906 ◽  
Vol 1 (4) ◽  
pp. 271-278
Author(s):  
H.D. Dakin
Keyword(s):  

1980 ◽  
Vol 13 (1) ◽  
pp. 193-194 ◽  
Author(s):  
Katsukiyo Ito

1961 ◽  
Vol 236 (5) ◽  
pp. 1280-1284
Author(s):  
K.E. Richardson ◽  
N.E. Tolbert

2020 ◽  
Vol 1200 ◽  
pp. 127082 ◽  
Author(s):  
Mansura Huseynova ◽  
Vaqif Farzaliyev ◽  
Ajdar Medjidov ◽  
Mahizar Aliyeva ◽  
Parham Taslimi ◽  
...  

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