I= STUDIES ON THE CHEMICAL CONSTITUENTS OF TINOSPORA MALABARICA, BUXUS PAPILLOSA AND FUMARIA INDICA; SYNTHETIC DEVELOPMENT OF NEW PROTECTING GROUPS OF ARGININE
Pakistan Research Repository Home
 

Title of Thesis
STUDIES ON THE CHEMICAL CONSTITUENTS OF TINOSPORA MALABARICA, BUXUS PAPILLOSA AND FUMARIA INDICA; SYNTHETIC DEVELOPMENT OF NEW PROTECTING GROUPS OF ARGININE

Author(s)
Syed Safdar Ali
Institute/University/Department Details
H.E.J Research Institute of Chemistry/ University of Karachi
Session
1994
Subject
Chemistry
Number of Pages
203
Keywords (Extracted from title, table of contents and abstract of thesis)
tinospora malabarica, buxus papillosa, fumaria indica; arginine, terpenoids, triterpenes

Abstract
This thesis describes phytochemical investigations on the medicinally important plants namely i) Buxus papillosa ii) Tinospora malabarica and iii) Fumaria, which have resulted in the isolation and characterization of six new constituents. In addition, five previously known constituents from other plant sources have also been isolated for the first time from these plant. Modern spectroscopic techniques including mass spectroscopy (EI, CI, HERIMS, FDMS etc.). Ultraviolet spectroscopy (UV), Infrared spectroscopy (IR), and one- and two-dimensional NMR experiments (1H, 13C, COSY-45ยบ, HOHAHA, 2D-J-resolved, HeteroCOSY, including inverse experiments HMQC and HMBC) were employed to elucidate their structure. The stereochemistry of the various asymmetric centres were established by NOE difference and X-ray diffraction studies

In addition to the isolation of natural products, syntheses of effective protecting groups for the gunaidino function of arginine were also under taken. Fmoc-based solid phase peptide synthesis is an ever growing interest in peptide synthesis but the side chain protection of arginine is still causing problems. Chapter five deals with the synthetic development of five new ary1 sulfony1-type guanidine protecting groups of arginine to study the factors influencing the acid liability of these groups. Three alkyl substituted synthons Tip (2,4,6-triisoprophylbenzenesulfony1), Mtbs (4-Methoxy-3,5-di-tert-butylbenzenesulfonyl) and Tbs (4-Methoxy-3-tert-butylbenzenesulfonyl) were synthesized. Furthermore, to observed the extended aromaticity over alkyl substituents, on the acid liability bicyclic Bip (Biphenyl-4-sulfonyl) and tricyclic Phen (Phenanthrene-3-sulfonyl) residues were synthesized. Kinetic investigations of these synthons were made with the conventionally used Mtr (4-methoxy-2,3,6-trimethylbenzenesulfonyl). The results obtained will provide fruitful help for the rational designing of new arylsulfonyl NG protecting groups cleavable under milder acidolytic condition and with less side effects.

Download Full Thesis
1460.81 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
133.47 KB
2 1 General Introduction 1
62.82 KB
3 2 Biosynthesis 8
235.54 KB
  2.1 Introduction 8
  2.2 Biosynthesis Of Terpenoids 11
  2.3 Biosynthesis Of Buxus Alkaloids 33
4 3 Results And Discussion 39
685.98 KB
  3.1 Introduction 39
  3.2 Triterpenes From The Roots Of Buxus Papillosa 40
  3.3 A New Alkaloid From The Roots Of Buxus Papillosa 67
  3.4 Know Constituents Unreported From Buxus Papillosa 77
  3.5 Terpenes From The Stems Of Tinospora Malabarica 86
  3.6 Known Constituents Isolated For The First Time From Tinospora Malabarica 113
  3.7 Constituents Of Fumaria Indica 118
5 4 Experimental 124
186.27 KB
  4.1 General Experimental Conditions 124
  4.2 Buxus Papillosa 128
  4.3 Tinospora Malabarica 140
6 5 Synthetic Development Of New Protecting Groups Of Arginine 151
290.9 KB
  5.1 Introduction 151
  5.2 Results And Discussion 155
  5.3 Experimental 170
  5.4 Kinetic Investigation 190
7 6 References 191
119.68 KB