Isolation, biotransformation, chemical modification and bioactivity studies of terpenoids from plant sources

Abstract

The thesis entitled “Isolation, Biotransformation, Chemical Modification and Bioactivity Studies of Terpenoids from Plant sources” consists of five chapters. The introduction is an overview of terpenoids, and plants viz. A. paniculata, W. paludosa G. tomantosum. Chapter second deals with the rapid isolation of diterpenoids from A. paniculata on preparative-scale was developed by using automated medium pressure liquid chromatography (MPLC) based technique and diterpenoids characterizations by ESI (+)-quadrupole/orbitrap-MS/MS and structure fragmentation pathway of daughter ions. Cytotoxicity of andrographolide was evaluated against MDA-MB-231, MCF-7 and studies 4-nitro-1,2,3-benzoxadiazole (NBD)-tag andrographolide internalization and localization in cancer cells. In chapter third C-14 ester analogues of andrographolide were synthesised through Amano lipase AK (P.fluorescens) catalysed acylation using various acyl donors. These monoesters tested for anti-microbial, hemolytic activity and investigated the mechanism of action by triple staining assay. Sophorolipid was used in order to enhance aqueous solubility and bioavailability of andrographolide and tested the cytotoxicity against MDA-MB-231. Zinc oxide nanoparticles were used as carriers for control pH release of andrographolide. Chapter fourth consists of isolation of lupane triterpenoids from the bark of Glochidion tomentosum on a preparative scale by medium automated pressure chromatographic technique. Self-assembly of glochidonol was investigated in different solvents and systematically studied by using advanced characterization techniques. The fibrillar microstructures of glochidonol have been utilised for the entrapping small molecule. Terpenoids were isolated from W. paludosa and kaurenoic acids derivatised were synthesised, which are evaluated for the glucosidase inhibitor activity. In Chapter four, whole-cell biotransformation of monoterpenoid (menthol), sesquiterpenoids (Z-lanceol) and diterpenoids (andrographolide) were systematically studied by using Mucor piriformis and Cunninghamella echinulata. Metabolites were tested for antimicrobial activity and evaluated the site of action by triple staining assay.