Antioxidative and radioprotective activities of semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1

• Published in: Molecular and cellular biochemistry Vol. 349; no. 1-2; pp. 57 - 67
• Main Authors: Kumar, Raj, Bansal, Deen Dayal, Patel, Dev Dutt, Mishra, Saurabh, Karamalakova, Yana, Zheleva, A, Gadjeva, Vessilina, Sharma, Rakesh Kumar
• Format: Journal Article
• Language: English
• Published: Boston Boston : Springer US 01.03.2011; Springer US; Springer; Springer Nature B.V
• Subjects: Analysis; Antioxidant; Antioxidants; Antioxidants - chemistry; Antioxidants - isolation & purification; Ascorbic Acid - chemistry; Bacillus; Bacillus - chemistry; Bacteria; Benzothiazoles - chemistry; Biochemistry; Biomedical and Life Sciences; Biphenyl Compounds - chemistry; Cardiology; electron paramagnetic resonance spectroscopy; Electron Spin Resonance Spectroscopy; free radical scavengers; Free Radical Scavengers - chemistry; Free Radical Scavengers - isolation & purification; Free radicals; Gamma rays; Glucosides - chemistry; Glucosides - isolation & purification; Hydroxyl Radical - chemistry; Life Sciences; Lipid Peroxidation; Liposomes - chemistry; Liposomes - radiation effects; Medical Biochemistry; Membrane protection; Monosaccharides; Neutralization; Nitric oxide; Nitric Oxide - chemistry; Nuclear radiation; Oncology; Oxidation-Reduction; Peroxidation; Picrates - chemistry; Quinone; Radiation-Protective Agents - chemistry; Radiation-Protective Agents - isolation & purification; Spectral analysis; Spectrometry; Sugars; Sulfonic Acids - chemistry; Free radical scavenging; Electron paramagnetic resonance; ntioxidant; Membrane protection
• ISSN: 0300-8177; 1573-4919
• DOI: 10.1007/s11010-010-0660-x

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 Uabs) 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) gy 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.