Distinguishing the 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-OH radical quenching effect from the hydroxyl radical scavenging effect in the ESR spin-trapping method

2004 ◽  
Vol 512 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Linxiang Li ◽  
Yoshihiro Abe ◽  
Kiyotada Kanagawa ◽  
Noriko Usui ◽  
Kazuhiro Imai ◽  
...  
Author(s):  
HIROSHI UKAI ◽  
TAKASHI ICHINOHE ◽  
SATORU MATSUMOTO ◽  
MUTSUMI KIMURA ◽  
TOSHIKI KOYAMA ◽  
...  

The bactericidal activity of an electrochemical system with a cobalt(II) phthalocyanine-modified Ti electrode was studied. In the presence of NaBO 3, strong bactericidal activity was observed against E. coli with electroreduction for 30 min. If an unmodified Ti electrode was used, no bactericidal activity was observed in the electrochemical system. By the ESR spin-trapping method using 5,5-dimethyl-1-pyrroline-N-oxide as the spin-trapping reagent, the radical species generated in the electrocatalytic reaction was found to be hydroxyl radical, which acts as the potent cytocidal species in the system.


Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1295
Author(s):  
Yuan Chen ◽  
Yingqi Mi ◽  
Jingjing Zhang ◽  
Fang Dong ◽  
Qing Li ◽  
...  

Many saccharides are attractive targets for biomaterial applications, due to their abundance, biocompatibility, and biodegradability. In this article, a synthesis process of 6-N-substituted cationic inulin derivatives, including 6-pyridyl-6-deoxyinulin bromide (PIL), 6-(2-amino-pyridyl)-6-deoxyinulin bromide (2APIL), 6-(3-amino-pyridyl)-6-deoxyinulin bromide (3APIL), 6-(4-amino-pyridyl)-6-deoxyinulin bromide (4APIL), 6-(2,3-diamino-pyridyl)-6-deoxyinulin bromide (2,3DAPIL), 6-(3,4-diamino-pyridyl)-6-deoxyinulin bromide (3,4DAPIL), and 6-(2,6-diamino-pyridyl)-6-deoxyinulin bromide (2,6DAPIL) was described. The C6-OH of inulin was first activated by PPh3/N-bromosuccinimide (NBS) bromination. Then, pyridine and different kinds of amino-pyridine groups (different position and different numbers of amino) were grafted onto inulin, respectively, via nucleophilic substitution. Then, we confirmed their structure by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. After this, their radical scavenging activities against hydroxyl radical and diphenylpicryl phenylhydrazine (DPPH) radical were tested in vitro. Each derivative showed a distinct improvement in radical scavenging activity when compared to inulin. The hydroxyl-radical scavenging effect decreased in the following order: 3APIL > PIL > 3,4DAPIL > 4APIL > 2,3DAPIL > 2,6DAPIL > 2APIL. Amongst them, 3APIL revealed the most powerful scavenging effect on hydroxyl radicals, as well as DPPH radicals. At 1.6 mg/mL, it could completely eliminate hydroxyl radicals and could clear 65% of DPPH radicals. The results also showed that the steric hindrance effect and the substitute position of the amino group had an effect on the radical scavenging activity. Moreover, the application prospects of inulin derivatives as natural antioxidant biomaterials are scientifically proven in this paper.


2001 ◽  
Vol 896 (1-2) ◽  
pp. 165-168 ◽  
Author(s):  
Yen-Kung Chen ◽  
Hui-Ching Lin ◽  
Jiang-Chuan Liu ◽  
Fang-Jung Wan

2012 ◽  
Vol 28 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Md Atiar Rahman ◽  
Rumana Sharmin ◽  
Md Nazim Uddin ◽  
Md Sohel Rana ◽  
Nazim Uddin Ahmed

Antibacterial effect of Crinum asiaticum bulb extract (1mg/disc) was tested on four Gram- positive and six Gram-negative bacteria by disc diffusion method using kanamycin (30 ìg/disc) as standard antibiotic disc. The bulb extract (250-1000mg/disc) showed significant zone of inhibition against all Gram-positive and Gram-negative bacteria ranging from 12-14 mm in diameter. Antioxidant potential of the same extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The extract showed remarkable free radical scavenging effect (95.96%) providing the IC50 value of 5.62 for the bulb extract and 5.46 for ascorbic acid (standard antioxidant) at the concentration of 1000 ìg/ml. The bulb extract was found to be (LC50 value 94.06 ?g/ml) in Brine-Shrimp lethality test. DOI: http://dx.doi.org/10.3329/bjm.v28i1.11801 Bangladesh J Microbiol, Volume 28, Number 1, June 2011, pp 1-5


Sign in / Sign up

Export Citation Format

Share Document