Spin-trapping Study of DNA Cleavage Induced by Enediyne C-1027 Chromophore

2002 ◽  
Vol 31 (11) ◽  
pp. 1148-1149 ◽  
Author(s):  
Toyonobu Usuki ◽  
Masayuki Inoue ◽  
Kimio Akiyama ◽  
Masahiro Hirama
Keyword(s):  
1999 ◽  
Vol 54 (1-2) ◽  
pp. 94-99 ◽  
Author(s):  
Satoshi Nishino ◽  
Teruyuki Kobayashi ◽  
Mami Kunita ◽  
Sayo Ito ◽  
Yuzo Nishida

The reactivity of copper(II) compounds with several tetradentate ligands towards some spin-trapping reagents was studied in the presence of hydrogen peroxide. The compounds used in this study are roughly divided into two groups based on the reactivity towards 2 ,2 ,6 ,6 -tetramethyl-4-piperidinol(and also 2,2,6,6-tetramethyl-4-piperidone), which are trapping agents for singlet oxygen, 1O2 (1Δg); The A-group compounds exhibited a high activity to form the corresponding nitrone radical, which was detected by ESR spectroscopy, but corresponding activity of the B-group compounds was very low. The A-group compounds defined as above exhibited high activity for cleavage of DNA(supercoiled Form I) in the presence of hydrogen peroxide, yielding DNA Form II (relaxed circular) or Form III (linear duplex) under our experimental conditions ([Cu(II)]=0.1~0.5 mᴍ). On the other hand, the B-group compounds effected complete degradation of the DNA (double-strand scission) under the same experimental conditions, formation of Form II or Form III DNA was negligible. Two different DNA cleavage patterns observed for A-and B-group compounds were elucidated by the different structural property of the copper(II)-peroxide adducts, which is controlled by the interaction through both DNA and the peripheral group of the ligand system


2014 ◽  
Vol 27 (4) ◽  
pp. 674-682 ◽  
Author(s):  
Birandra K. Sinha ◽  
Fabian Leinisch ◽  
Suchandra Bhattacharjee ◽  
Ronald P. Mason

1998 ◽  
Vol 38 (6) ◽  
pp. 147-154 ◽  
Author(s):  
Hideo Utsumi ◽  
Sang-Kuk Han ◽  
Kazuhiro Ichikawa

Generation of hydroxyl radicals, one of the major active species in ozonation of water was directly observed with a spin-trapping/electron spin resonance (ESR) technique using 5,5-dimethyl-1-pyrrolineN-oxide (DMPO) as a spin-trapping reagent. Hydroxyl radical were trapped with DMPO as a stable radical, DMPO-OH. Eighty μM of ozone produced 1.08 X 10-6M of DMPO-OH, indicating that 1.4% of •OH is trapped with DMPO. Generation rate of DMPO-OH was determined by ESR/stopped-flow measurement. Phenol derivatives increased the amount and generation rate of DMPO-OH, indicating that phenol derivatives enhance •OH generation during ozonation of water. Ozonation of 2,3-, 2,5-, 2,6-dichlorophenol gave an ESR spectra of triplet lines whose peak height ratio were 1:2:1. ESR parameters of the triplet lines agreed with those of the corresponding dichloro-psemiquinone radical. Ozonation of 2,4,5- and 2,4,6-trichlorophenol gave the same spectra as those of 2,5- and 2,6-dichlorophenol, respectively, indicating that a chlorine group in p-position is substituted with a hydroxy group during ozonation. Amounts of the radical increased in an ozone-concentration dependent manner and were inhibited by addition of hydroxyl radical scavengers. These results suggest that p-semiquinone radicals are generated from the chlorophenols by hydroxyl radicals during ozonation. The p-semiquinone radicals were at least partly responsible for enhancements of DMPO-OH generation.


2019 ◽  
Vol 15 (5) ◽  
pp. 445-455 ◽  
Author(s):  
Suraj N. Mali ◽  
Sudhir Sawant ◽  
Hemchandra K. Chaudhari ◽  
Mustapha C. Mandewale

Background: : Thiadiazole not only acts as “hydrogen binding domain” and “two-electron donor system” but also as constrained pharmacophore. Methods:: The maleate salt of 2-((2-hydroxy-3-((4-morpholino-1, 2,5-thiadiazol-3-yl) oxy) propyl) amino)- 2-methylpropan-1-ol (TML-Hydroxy)(4) has been synthesized. This methodology involves preparation of 4-morpholino-1, 2,5-thiadiazol-3-ol by hydroxylation of 4-(4-chloro-1, 2,5-thiadiazol-3-yl) morpholine followed by condensation with 2-(chloromethyl) oxirane to afford 4-(4-(oxiran-2-ylmethoxy)-1,2,5-thiadiazol- 3-yl) morpholine. Oxirane ring of this compound was opened by treating with 2-amino-2-methyl propan-1- ol to afford the target compound TML-Hydroxy. Structures of the synthesized compounds have been elucidated by NMR, MASS, FTIR spectroscopy. Results: : The DSC study clearly showed that the compound 4-maleate salt is crystalline in nature. In vitro antibacterial inhibition and little potential for DNA cleavage of the compound 4 were explored. We extended our study to explore the inhibition mechanism by conducting molecular docking, ADMET and molecular dynamics analysis by using Schrödinger. The molecular docking for compound 4 showed better interactions with target 3IVX with docking score of -8.508 kcal/mol with respect to standard ciprofloxacin (docking score= -3.879 kcal/mol). TML-Hydroxy was obtained in silico as non-carcinogenic and non-AMES toxic with good percent human oral absorption profile (69.639%). TML-Hydroxy showed the moderate inhibition against Mycobacteria tuberculosis with MIC 25.00 μg/mL as well as moderate inhibition against S. aureus, Bacillus sps, K. Pneumoniae and E. coli species. Conclusion: : In view of the importance of the 1,2,5-thiadiazole moiety involved, this study would pave the way for future development of more effective analogs for applications in medicinal field.


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