University of Madras

About: University of Madras is a education organization based out in Chennai, Tamil Nadu, India. It is known for research contribution in the topics: Ring (chemistry) & Lipid peroxidation. The organization has 8496 authors who have published 11369 publications receiving 211152 citations. The organization is also known as: Madras University & University of Chennai.

Supplementation of ascorbic acid and α-tocopherol prevents arsenic-induced protein oxidation and DNA damage induced by arsenic in rats

Abstract: Contamination of arsenic in drinking water is associated with several human diseases including cancer. It has been reported that oxidative stress plays a vital role in arsenic-induced biochemical and molecular alterations. The aim of the present study was to improve the understanding of arsenic-induced oxidative damage to proteins and to DNA and the role of antioxidants such as ascorbic acid and alpha-tocopherol in alleviating arsenic-induced damages in experimental rats. A significant increase in the levels of protein oxidation, DNA strand breaks, and DNA-protein cross-links was observed in blood, liver, and kidney of rats exposed to arsenic (100 ppm in drinking water) for 30 days. Co-administration of ascorbic acid and alpha-tocopherol to arsenic-exposed rats showed a substantial reduction in the levels of arsenic-induced oxidative products of protein and DNA. The results of this study support that free radical-mediated toxic manifestations of arsenic and also suggest that ascorbic acid and alpha-tocopherol supplementation can improve the arsenic-induced molecular alterations.

Dual responsive chemosensors for anion and cation: Synthesis and studies of selective chemosensor for F― and Cu(II) ions

Abstract: New colorimetric chemosensors, 1-[2-{(4-nitrobenzylidene)amino}phenyl]-3-phenylthiourea ( 1 ), 1-[2-{(2-hydroxy-5-nitrobenzylidene)amino}phenyl]-3-phenyl thiourea ( 2 ) have been synthesized and characterized by spectroscopic techniques and XRD. The molecular structure of receptor 1 was determined by X-ray crystallography and it has the triclinic space group P 1 with cell parameters a = 7.2705 A (6), b = 11.0178 A (9) c = 12.0137 (9) A and Z = 2. Anion binding studies carried out using 1 H NMR and UV–visible spectrophotometric titrations revealed that these receptors exhibit selective recognition towards F − over other halide anions. The selectivity for F − among the halides is attributed mainly to the hydrogen-bond interaction of the receptor with F − . Receptors 1 and 2 (5 × 10 −5 M) show color change from colorless to brown and yellow respectively in the presence of tetrabutylammonium fluoride (TBAF, 5 × 10 −3 M). Moreover, F − -induced color changes remain the same even in the presence of large excess of Cl − , Br − , and I − . Chromogenic receptors 1 and 2 undergo distinct color changes from colorless to violet ( 1 ) or bluish green ( 2 ) on gradual addition of Cu(II) and can be used as colorimetric probes for spectrophotometric and visual analysis of Cu(II) in the presence of other transition metal ions such as Mn 2+ , Co 2+ , Ni 2+ and Zn 2+ . The binding constant for 2 was found to be higher than that for 1 towards F − and Cu(II) ion and this may be due to presence of OH group in 2 , which offers extra binding site.

Quantification of microplastic in Red Hills Lake of Chennai city, Tamil Nadu, India.

Abstract: Inevitable use of plastic materials in our day-to-day life has led to the entry of microplastic into aquatic environments, which are plastics less that than 5 mm. Microplastic is of great concern in recent years due to its impact on humans and aquatic organisms since they absorb organic contaminants and pathogens from the surrounding media due to higher surface and volume ratio. This is the first study attempted to study the distribution and source of microplastic contamination in Red Hills Lake which is one of the freshwater systems supplying water to the North of Chennai city. Thirty-two sediment samples and six water samples were collected covering an area 18.21 km2. The presence of microplastic was analyzed in water and sediment as per the National Oceanic and Atmospheric Administration (NOAA) protocol. The mean concentration of microplastic in water samples was 5.9 particles/L and 27 particles/kg in sediment. In both sediments and water, the most commonly found microplastic types are as follows: fibers (37.9%), fragments (27%), films (24%), and pellets (11.1%). Based on the FTIR, the common types of microplastic were of high-density polyethylene, low-density polyethylene, polypropylene, and polystyrene. Further samples were evaluated for surface elemental composition in order to understand whether heavy metals get adhered to the surface of microplastic using energy-dispersive X-ray. Our results indicated the presence of microplastic in water and sediments which will lead to further study of microplastic presence in biota and microplastic pollution in freshwater systems.