Laxminarayana, Burgula2015-09-232023-10-192015-09-232023-10-192014ROLL NO.09612217https://gyan.iitg.ac.in/handle/123456789/526Supervisor: Lal Mohan KunduThe contents of this thesis entitled on the Synthesis and Properties of Modified Pyrimidine Nucleobases, Bis-Pyrimidine Dimers and Peptide Nucleic Acids is divided into six chapters based on the results of experimental work performed during the research tenure. The introductory chapter of the thesis presents an overview of various synthetic routes of modified nucleic acids and their applications in biomolecular research. Chapter-II describes the synthesis of unnatural uracil, cytosine, thiouracils and thiocytosine derivatives using a microwave-assisted method. Chapter-III demonstrates an efficient chemo-selective, microwave-assisted methodology for direct synthesis of N-3 alkylated and arylated pyrimidinones from their beta-carbonylester precursors. Chapter-IV illustrates the design and synthesis of self-assembled, novel modified nucleobases for supra-molecular architectures. Chapter-V deals with the synthesis of C-5 and C-6 substituted modified pyrimidine homo- and hetero-dimers and the study of UV-induced photochemical damages, where, a number of synthesized pyrimidinones show remarkable stabilities under UV-radiation. Chapter-VI mainly focuses on synthesis of modified peptide nucleic acid (PNA) which forms stable duplex with DNA. Each chapter consists of four sub sections: introduction, present work, experimental methods and spectral data.enCHEMISTRYThesis