14042-01-4

Facile and efficient reduction of graphene oxide (GO) and novel applications of the reduced graphene oxide (RGO) based materials are of current interest. Herein, we report a novel and facile method for the reduction of GO by using a biocompatible reducing agent dithiothreitol (DTT). Stabilization of DTT by the formation of a six-membered ring with internal disulfide linkage upon oxidation is responsible for the reduction of GO. The reduced graphene oxide is characterized by several spectroscopic and microscopic techniques. Dispersion of RGO in DMF remained stable for several weeks suggesting that the RGO obtained by DTT-mediated reduction is hydrophobic in nature. This method can be considered for large scale production of good quality RGO. Treatment of RGO with hemin afforded a functional hemin-reduced graphene oxide (H-RGO) hybrid material that exhibited remarkable protective effects against the potentially harmful peroxynitrite (PN). A detailed inhibition study on PN-mediated oxidation and nitration reactions indicate that the interaction between hemin and RGO results in a synergistic effect, which leads to an efficient reduction of PN to nitrate. The RGO also catalyzes the isomerization of PN to nitrate as the RGO layers facilitate the rapid recombination of .NO2 with FeIV=O species. In the presence of reducing agents such as ascorbic acid, the FeIV=O species can be reduced to FeIII, thus helping to maintain the PN reductase cycle.

Two conformers (cis and trans) of potassium peroxynitrite (KOONO) were produced in an argon matrix containing potassium nitrate (KNO3) at 13 K by means of in situ photolysis with an ArF excimer laser at 193 nm. Photoconversion among cis- and trans-KOONO,

Abstract: The study was aimed to evaluate the impact of peroxynitrite (PON, oxidative stress agent in diabetes), methylglyoxal (MGO, diabetes-associated reactive carbonyl compound), and their simultaneous application on the structural and functional features of human αA-crystallin (αA-Cry) using various spectroscopy techniques. Additionally, the surface tension and oligomer size distribution of the treated and untreated protein were tested using tensiometric analysis and dynamic light scattering, respectively. Our results indicated that the reaction of PON and MGO with human αA-Cry leads to the formation of new chromophores, alterations in the secondary to quaternary protein structure, reduction in the size of protein oligomers, and significant enhancement in the chaperone activity of αA-Cry. To reverse the effects of the tested compounds, ascorbic acid and glutathione (main components of lens antioxidant defense system) were applied. As expected, the two antioxidant compounds significantly prevented formation of high molecular weight aggregates of αA-Cry (according to SDS-PAGE). Our results suggest that the lens antioxidant defense system, in particular, glutathione, may provide a strong protection against rapid incidence and progression of diabetic cataract by preventing the destructive reactions of highly reactive DM-associated metabolites.

Aim: The present study was expected to explore the molecular interaction of five oxida-tive stress (OS) associated target receptors with Alpha-Pinene and its antioxidant validation for the effective treatment of Parkinson’s disease (PD). Background: Oxidative stress (OS) via multitudinous cascades is considered to be the leading attrib-ute to dopaminergic cell degeneration in PD. Furthermore, it is also well-linked to other mechanisms involved in the neurodegeneration process, like dysfunction of mitochondria, neuroinflammation and excitotoxicity due to NO. Objective: The present investigation was to establish a molecular association of OS-associated target receptors with the bioactive compound alpha-pinene and how this molecular interaction empowers the mitigation of PD. Materials and Methods: Five different molecular targets namely Peroxisome Proliferator-Activated Receptor-Gamma (PPARγ), Liver-X receptor beta (LXR-β), Human Monoamine Oxidase-B (MAO-B), Human Nuclear receptor related-1 protein (Nurr1) and Human Lipoprotein-associated phospholipase A2 (Lp-PLA2) were obtained from RCSB-PDB, which has some leading association in the inhibition of the OS-induced neurodegeneration. Molecular interactions were stuffed by the simulation molecular docking software. Antioxidant activity was validated by in-vitro models as per standardized procedures against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Ferric ion (Fe3+), Hydroxyl (?OH), nitric oxide (?NO), Peroxynitrite (ONOO-) and Hypochlorous acid (HOCl). Results: Our results indicated that alpha-pinene can interact with all the five different target receptors at the active binding site. Alpha-pinene was found to show better interaction with MAO-B, Nurr1 and PPARγ with binding energy of-5.50,-4.52 and-5.25, respectively as compared to the native ligand. Furthermore, the interaction of alpha-pinene with LXR-β and Lp-PLA2 was also significant with binding energy of-5.6 and-5.12, respectively. It also capable of neutraliz-ing all the different free radicals under consideration with significant IC50 values against HOCl and ?NO. Conclusion: It might be concluded that alpha-pinene could act as a potential inhibitor and scavenger of OS which could act on the multiple target receptors under consideration.

Novel methods for the synthesis of 8-nitroguanine are provided. Compositions comprising 8-nitroguanine, made by the novel synthetic methods are also provided herein. Methods of use of 8-nitroguanine, made by the novel synthetic methods, as a standard for detection of 8-nitroguanine in samples are also encompassed within the scope of the present invention. The present invention further concerns methods of predicting organ transplant rejection and detecting exposure to environmental stressors, such as ionizing radiation, toxic chemicals or infectious agents, by detecting 8-nitroguanine in one or more samples from a transplant recipient or an organism exposed to stress.