ISOLATION AND STRUCTURAL STUDIES ON PHYTOCHEMICALS ACTIVE IN VARIOUS BIOLOGICAL ASSAYS

This dissertation is divided into three parts. Part A describes the results of phytochemical and bioassay studies on Lindelofia Stylosa (Kar. & Kir.), while the Part B deals with the isolation and characterization of compounds isolated from Bergenia Ciliate (How.) Sternb., and Part C illustrates the chemical constituents of Trigonellafoenum-Graecum L. </p><p>PART A :This part of the thesis describes the isolation and structure elucidation of seven new 1-7 and thirteen known glycosides and phenyl polypropanoides 8-20 from Lindelofia stylosa (Kar. & Kir.). The compounds 1-20 were found to posse's immunomoduladatory activity, while compounds 9-19 exhibited a potent anti-oxidant activity (IC50 values between 0.04 to 0.27 µM). The new constituents were identified as 3-O-feruloyl-6'-O-coumaroyl sucrose (1), 3- O-feruloyl-6'-O-caffeoyl sucrose (2), 3,6-O-diferuloyl-l-kestose (3), 3-O-feruloyl-6'-O-coumaroyl-l-kestose (4), 3,6- O-diferuloyl nystose (5), 3-0-feruloyl-6'- O- coumaroyl nystose (6), and ethyllithospermate (7).</p><p>---------------------------------------------------------------Snaps-----------------------------------------------------------</p><p>The structures of new compounds 1-7 were deduced on the basis of different spectroscopic techniques, including 1H- and 13C-NMR spectroscopy (HMQC, HMBC, ID-TOCSY, COSY 45°, etc). The known compounds 8-20 were isolated for the first time from Lindelofia stylosa and identified as 3,6'-O-diferuloylsucrose (8), 3-0-feruloyl fructofuranosyl sucrose (9), dimethyllithospermate (10), dimethyllithospermate B (11), rosmarinic acid (12), methyl rosmarinate (13), ethyl rosmarinate (14), butyl rosmarinate (15), p-coumaric acid (16), ferulic acid (17), 8-O-,B-D-glucopyranosyl torachrysone (18), naphthalene glycoside (8-O-,B-D-glucopyranoside) (19), and 4'-hydroxy-5-methoxy-6,7- methylenedioxyisoflavone (20).</p><p>---------------------------------------------------------------Snaps-----------------------------------------------------------</p><p>PART B :Part B of the thesis describes the phytochemical investigation on Bergenia ciliate (How.) Stemb., which has resulted in the isolation of three known compounds, identified as bergenin (21), p-hydroxybenzoyl bergenin (22), and 11- O-galloyl bergenin (23).---------------------------------------------------------------Snaps-----------------------------------------------------------PARTC : Part C of the thesis describes the isolation of secondary metabolites from Trigonella foenum-gracecum L. This has resulted in the isolation of two known constituents, identified as kaempferol-7 -O-α-rhamnoside (24) and kaempferol-3-O- α -L- rhamnopyranoside-7 -O- α -L-rhamnopyranoside (25