Chemical and biotransformation studies of some bioactive phenolics and heterocyclic compounds

Abstract

This thesis is divided into four chapters: Chapter 1 Biocatalytic oxidative C=C bond cleavage and C-C bond formation studies on phenolic derivatives in ionic liquid media Chapter 2 Synthesis of allylated chalcones and their derivatives with enhanced solubility for antimalarial and pesticidal activity Chapter 3 Green synthesis of some bioactive heterocyclic compounds from natural precursors Chapter 4 Isolation, chromatographic evaluation and application of phenolic rich colored compounds/fractions from plants Chapter 1: Biocatalytic oxidative C=C bond cleavage and C-C bond formation studies on phenolic derivatives in ionic liquid media The formation and cleavage of carbon-carbon bonds is of central importance in organic chemistry which provides a facile access to several commercially and biologically viable compounds. Oxidative C=C cleavage and C C coupling have been traditionally carried out with the use of metal-based catalysts. At the moment, biocatalysis has been considered to be a promising green methodology to overcome the necessity of metals in catalysis. This chapter deals with a biocatalytic approach for the metal-free direct synthesis of one or two carbon shorter aldehydes from 2o aryl alcohols through oxidative C=C bond cleavage. Furthermore, the study presents an efficient, simple and green methodology for aldol, Knoevenagel and Knoevenagel-Doebner condensations using a synergistic combination of BSA-[bmim]Br; thus highlighting the role of protein impurities in porcine pancreas lipase (rather than catalytic promiscuity) for olefinic bond formations. Chapter 2: Synthesis of allylated chalcones and their derivatives with enhanced solubility for antimalarial and pesticidal activity Chalcones and their derivatives have attracted significant attention in medicinal, synthetic and natural product chemistry due to numerous pharmacological applications among which antimalarial activity is most conspicuous.