Antioxidative and radioprotective activities of semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1.
A semiquinone glucoside derivative (SQGD) was isolated from a radioresistant bacterium Bacillus sp. INM-1 and its antioxidant and radioprotective activities were evaluated using in vitro assays. Natural stable free radical properties of SQGD in solid as well as in solution form were estimated using Electron Paramagnetic Resonance (EPR) spectrometry. Results of the study were demonstrated high reducing power (1.267 ± 0.03356 U(abs)) and nitric oxide radicals scavenging activity (34.684 ± 2.132%) of SQGD. Maximum lipid peroxidation inhibitory activity of SQGD was found to be 74.09 ± 0.08% at 500 μg/ml concentration. Similarly, significant (39.54%; P < 0.05) protection to the liposomal artificial membrane against gamma radiation was observed by SQGD in terms of neutralization of gamma radiation-induced TBARS radicals in vitro. OH(-) radicals scavenging efficacy of SQGD was estimated in terms of % inhibition in deoxy D: -ribose degradation by non-site-specific and site-specific assay. The maximum (54.01 ± 1.01%) inhibition of deoxy D: -ribose degradation was observed in non-site-specific manner, whereas, site-specific inhibition was observed to be 46.36 ± 0.5% at the same concentration (250 μg/ml) of SQGD. EPR spectroscopic analysis of the SQGD indicated ~80% reduction of DPPH radicals at 6.4% concentration. EPR spectral analysis of SQGD was revealed an appearance of very strong EPR signal of 2.00485 (crystalline form) and 2.00520 (solution form) g(y) tensor value, which were an established characteristic of o-semiquinone radicals. Therefore, it can be concluded that SQGD is a natural stable o-semiquinone-type radical, possessing strong antioxidant activities and can effectively neutralize radiation induced free radicals in biological system.
Institute of Nuclear Medicine and Allied Sciences, Delhi, India. rajkumar790@yahoo.com
Raj
R
Kumar
Deen Dayal
DD
Bansal
Dev Dutt
DD
Patel
Saurabh
S
Mishra
Yana
Y
Karamalakova
A
A
Zheleva
Vessilina
V
Gadjeva
Rakesh Kumar
RK
Sharma
D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D001205:Ascorbic Acid / Q000737:chemistry; D001407:Bacillus / Q000737:chemistry*; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification*; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification*; D017665:Hydroxyl Radical / Q000737:chemistry; D015227:Lipid Peroxidation; D008081:Liposomes / Q000737:chemistry / Q000528:radiation effects; D009569:Nitric Oxide / Q000737:chemistry; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D011837:Radiation-Protective Agents / Q000737:chemistry / Q000302:isolation & purification*; D013451:Sulfonic Acids / Q000737:chemistry
D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005960:Glucosides; D008081:Liposomes; D010851:Picrates; D011837:Radiation-Protective Agents; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D009569:Nitric Oxide; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid