Shirish Kumar Kodadi

Synthesis, Spectrophotometric, Spectroscopic and Computational Studies of Charge Transfer Complexes of Anticancer Agents Shirish Kumar Kodadi

Available chemical literature has witnessed a profound increase in the number of spectrophotometric procedures over the years and more reagents are being introduced regularly for the analysis of drugs/bioactive molecules. The reason is not farfetched as most of the developed methods are preferably cheaper, simpler and adopt more ready instrumentation compared to sophisticated techniques like HPLC, GC, capillary electrophoresis, bioassays and other techniques. The relevance of spectrophotometric methodologies will continue to increase as the years go by because of the increased cost of analysis of pharmaceuticals when sophisticated techniques are adopted. The recent pharmacopoeias however, are filled with methodologies involving some of these expensive techniques with the spectrophotometric procedures are now reserved to simple test tube reactions for the purpose of identification. However, it is anticipated that spectrophotometric methodologies will continue to be relevant in poor resource economies for the assessment of the bio-active molecules/drugs, accordingly introduction of newer spectrophotometric methods and reagents in the near future cannot be ruled out. Comprehending the charge transfer process between bioactive molecules and inorganic or organic molecules is significant as this interaction can be used to interpret the bioactive molecules receptor interactions. Accordingly, spectrophotometric method has been developed for the determination of Anticancer agents using acceptor. This method is based on the element of decrease in intensity of colour produced by the reaction of Anticancer agents with acceptor in suitable solvent at room temperature. The spectrophotometric measurement has been made at high absorption maximum. All formed complexes exhibit well resolved charge transfer bands in this region where neither donor nor acceptor has appreciable absorption at high absorption maximum. The binding ratio of complexation has been determined to be 1:1 & 1:2 for the acceptor with the Anticancer agents. The spectroscopic parameters like association constant (K), extinction coefficient (emax), ionization potential (IP), energy of the charge transfer complex (ECT), resonance energy (RN), dissociation energy (W) and standard Gibbs free energy (DG0) have been computed. Driven by a steady improvement of computational hardware and significant progress in ab initio method development, quantum-mechanical approaches can now be applied to study the charge transfer process between bioactive molecules and the acceptor molecules. Accordingly, in order to support experimental studies, computational study is carried using General Atomic and Molecular Electronic Structure System (GAMESS) computations as a package of chem Bio 3D ultra 12.0, MM2 method has been applied at Restricted Hartree-Fock (RHF)/3-21G level for energy optimization of Anticancer agents and acceptor molecules. A good consistency between experimental and computational results has been found.