pH-Dependent Ion Binding Studies on 2-Mercaptopyrimidine Kamara B 1* , Kamara HM 1 and Phambu N 2 1 Department of Chemistry, Morgan State University, Baltimore, Maryland, USA 2 Department of Chemistry, Tennessee State University, Nashville, Tennessee, USA *Corresponding author: Kamara B, Department of Chemistry, Morgan State University, Baltimore, Maryland, USA, Tel: +443-885-3794; E-mail: beebeekamara@gmail.com Received date: August 03, 2018; Accepted date: August 12, 2018; Published date: August 15, 2018 Copyright: © 2018 Kamara B, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Mercaptopyrimidines exhibit antiviral and antibacterial properties and were found to inhibit the synthesis of tRNA thus acting as antitumor and antithyroid agents. These molecules exhibit tautomeric equilibrium between the thiol and thione because of the highly mobile protons they possess. These compounds can incorporate metal ions in their structure because they possess electron donor atoms. Metal ions are electron acceptor species; they come from food, medicine, and drinking water. The objective of this project was to investigate whether and how metal ions such as Na + , Hg 2+ , Al 3+ , Ce 4+ , and UO 22+ affect the structure of 2-mercapto pyrimidine using electronic and Vibrational spectroscopes. Binding studies were conducted in aqueous solutions at different pH and metal ion/ligand molar ratios. It is hypothesized that interaction does occur between metal ions of valence other than two and certain numbers of 2-Mercaptopyrimidine. However, the interactions tend to differ from one metal ion to another depending on the charge of the metal ion. The electronic spectra have shown, the pH affects the structure of 2MCP, the thione form is the dominant species in water, and all the metal ions cited above interact with a 2-mercapto pyrimidine. But Hg 2+ and Ce 4+ interact with 2- mercapto pyrimidine more strongly than Na + , Al 3+ , and UO 22+ . The stability constant calculated using electronic spectra and a Scatchard plot demonstrated that the complexes of Hg and Ce with 2-mercapto pyrimidine are the most stable. Keywords: Analytical chemistry; Biochemistry; Antioxidant activities; Antibacterial activities; Spectroscopy Introduction Metal ions come from food, medicine and drinking water [1]. An understanding of their role in the biological systems has become essential to the practice of medicine. Te presence of metal ions has been associated with the misfolding process of proteins and structural change in DNA, leading to some types of cancers, and neurodegenerative diseases [2,3]. Metal ions released by antacid preparations resulted in a nearly complete loss of activity of antibacterial [3,4]. So it is mandatory that the efect of metal ions on the structure (thus on the activity) of some pharmaceuticals be investigated. Tere is a need to better understand potential metal ion- pharmaceuticals interactions in order to reduce possible adverse efects or enhance the efcacy of the drugs being employed and to better inform patients [5-10]. Te chemistry of mercapto pyrimidines is attracting research interest because it involves both S and N atoms in their structures [10,11]. Tere is a considerable versatility in the coordination modes of these molecules, which may include monodentate binding through S or through N, bridging through a single S, and bridging through both S and N or chelating via S to N backbone. In other terms, these compounds can coordinate as monodentate ligands and more frequently as polydentate ligands either to a single metal center, acting as a chelating ligand, or to several metal centers as bridging ligand. In addition, these compounds exhibit a tautomeric equilibrium between the >C-SH (thiol) and the >C=S (thione) form due to the highly polar protons they possess (Figure 1). Te predominant form largely depends on the state and conditions of the molecule [11]. However, in the solution phase, there are several factors infuencing the tautomeric equilibrium. Among the most prominent are the solvent, temperature, pH, and concentration. Tus, it was suggested that the thione form predominates over the thiol form in a polar solvent; while the thiol form predominates in a polar solvent. Figure 1: Tautomeric equilibrium of 2 – Mercaptopyrimidine. Te Pharmaceutical drug 2-mercapto pyrimidine is the thione form. Te sulfur atom in the thione attacked the excess iodine on people that have thyroid diseases. Terefore, it is very important for the availability of the sulfur atom in the thione form of 2-mercapto pyrimidine. Among these mercapto pyrimidine compounds, we have chosen to focus on 2-mercapto pyrimidine (2-MCP). Tis drug is used in the treatment of Hashimoto’s thyroiditis and Grave’s disease, which are the two most common autoimmune thyroid disorders [6]. Although anti- thyroid drugs have been used for over 50 years, their mechanisms of J o u r n a l o f E n v i r o n m e n t a l A n a l y t i c a l C h e m i s t r y ISSN: 2380-2391 Journal of Environmental Analytical Chemistry Kamara et al., J Environ Anal Chem 2018, 5:3 DOI: 10.4172/2380-2391.1000245 Research Article Open Access J Environ Anal Chem, an open access journal ISSN: 2380-2391 Volume 5 • Issue 3 • 1000245