Bimolecular interaction of argpyrimidine (a Maillard reaction product) in in vitro non-enzymatic protein glycation model and its potential role as an antiglycating agent.

Non- enzymatic glycation, also known as Maillard reaction, is one of the most important and investigated reactions in biochemistry. Maillard reaction products (MRPs) like protein-derived advanced glycation end products (AGEs) are often referred to cause pathophysiological complications in human systems. On contrary, several MRPs are exogenously used as antioxidant, antimicrobial and flavouring agents. In the preset study, we have shown that argpyrimidine, a well-established AGE, interacts with bovine serum albumin (BSA) and glucose individually in standard BSA-glucose model system and successfully inhibits glycation of the protein. Bimolecular interaction of argpyrimidine with glucose or BSA has been studied independently. Chromatographic purification, different spectroscopic studies and molecular modeling have been used to evaluate the nature and pattern of interactions. Binding of argpyrimidine with BSA prevents incorporation of glucose inside the native protein. Argpyrimidine can also directly entrap glucose. Both these interactions may be associated with the antiglycation potential of argpyrimidine, indicating a beneficial function of an AGE.

Anthraimidazoledione Based Reversible and Reusable Selective Chemosensors for Fluoride Ion: Naked-Eye, Colorimetric and Fluorescence "ON-OFF".

Novel anthraimidazoledione-based compounds (1-3) are synthesized as selective colorimetric and fluorescent sensors for fluoride ion. The binding properties of the probes (1-3) are studied with different anions in acetonitrile solvent. Spectral red shifts in the absorption spectra and 'turn-off' emission are observed when fluoride is added to 1-3. The striking green to orange color change in the ambient light is thought to be due to the deprotonation of the N-H proton of the imidazole moiety of the probes by the basic F- ion. Interestingly, in all three cases the nonfluorescent probe-F- solutions, on treatment with copper perchlorate, show distinct color change from orange to golden yellow with resumption of fluorescence intensity. Furthermore, the reversibility of sensors (1-3) for the detection of F- ion is tested for four cycles indicating that "ON-OFF-ON" mechanism is operative. Test strip based on sensor 2 acts as a reusable cost-effective F- sensor.

Argpyrimidine-tagged rutin-encapsulated biocompatible (ethylene glycol dimers) nanoparticles: Synthesis, characterization and evaluation for targeted drug delivery.

Diabetes mellitus represents a major metabolic disorder affecting millions of people all over the world. Currently available therapeutic treatments are not good enough to control the long-term complications of diabetes. Active targeting via inclusion of a specific ligand on the nanoparticles provides effective therapeutic approach in different diseases. However, such specific drug delivery systems have not been explored much in diabetes due to lack of suitable biological targets in this disorder. Our objective is to synthesize a ligand-tagged drug-loaded nanoparticle for delivery of the drug at specific sites to enhance its therapeutic efficiency in diabetic condition. The nanoparticles have been prepared by using biocompatible ethylene glycol-bis (succinic acid N-hydroxysuccinimide ester) dimers. Although advanced glycation end products (AGEs) are the root causes of diabetic complications, argpyrimidine, an AGE, possesses antioxidant and reducing activities. AGE interacts selectively with its cell surface receptors (RAGE), which are significantly increased in diabetic condition. We have selected RAGE as the target of argpyrimidine, which is tagged on the nanoparticles as a ligand. Rutin, having anti-hyperglycemic and anti-glycating activities, has been used for nanoencapsulation. Rutin-loaded argpyrimidine-tagged nanoparticles have been synthesized and characterized. We have demonstrated the drug releasing capacity and target specificity of the synthesised drug delivery system under ex vivo and in vivo conditions.