I= ISOLATION AND STRUCTURAL STUDIES ON THE CHEMICAL CONSTITUENTS OF RHAZYA STRICTA, ALSTONIA MACROPHYLLA AND RELATED MEDICINAL PLANTS
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Title of Thesis
ISOLATION AND STRUCTURAL STUDIES ON THE CHEMICAL CONSTITUENTS OF RHAZYA STRICTA, ALSTONIA MACROPHYLLA AND RELATED MEDICINAL PLANTS

Author(s)
Mhammad Munawar Qureshi
Institute/University/Department Details
University of Karachi/H.E.J. Research Institute of Chemistry
Session
1991
Subject
Chemistry
Number of Pages
238
Keywords (Extracted from title, table of contents and abstract of thesis)
rhazya stricta, alstonia macrophylla, medicinal plants, alkaloids, neisosperma oppositifiolia, swertia cordata, primula denticulata

Abstract
This thesis is divided into two parts. Part A describes the isolation and structural studies on the alkaloids from Rhazya stricta, Alstonia macrophylla and Neisosperma oppositifolia.

Phytochemical investigations on the alkaloidal contents of Rhazya stricta have resulted in the isolation of a new alkaloid along with two known bases, one of which is reported for the first time from this species:

N-Methylleuconolam (92) Heterocycles, (submitted for publication) 20 (R)-19,20-Dihydrocondylocarpine (101) Heterocycles, (submitted for publication). Rhazidigenine (102)

Work on the alkaloidal extracts of leaves of Alstonia macrophylla have led to the isolation of a new oxindole alkaloid along with five known alkaloids, two of which are reported for the first time from this species:

i.16-Hydroxy-Nb-demethylalstopylline oxindole (103) Heterocycles, 27(3), 725 (1988). N-Methyl-1,2-dihydrostrictamine (107) Heterocycles, 27(3), 725 (1988). iii.Alstonisine (106 Fitoterapia, 1, 91 (1990). Quebrachidine (109) Fitoterapia, 1,91 (1990) Nb-Demethlalstophylline oxindole (110) Vincorine (111)

Alkaloidal extracts of Neisosperma oppositifolia upon investigation have produced a new oxindole alkaloid along with an oxindole previously known from other sources. Three other known compounds were also isolated:

Neisosposinine (112) Heterocycles, 28(2), 999 (1989). Isocarapanaubine (117) Heterocycles, 28(2), 999 (1989). Isoreserplline (118) Heterocycles, 28(2), 999(1989). Reserpiline (119) Heterocycles, 28(2), 999(1989). Ochroposinine (120) Heterocycles, 28(2), 999(1989).

Part B of this thesis deals with the chemical constituents isolated from Rhazya stricta, Swertia cordata and Primula species:

Lupeol (121) Lupeol-3-O-acetate (122) Β-Sitosterol glucoside (123)

The following two new xanthones have been isolated from Swertia cordiata along with two previously known xanthones:

1-Hydroxy-3,5,7,8-tetramethoxyxanthone (124) J. Nat. Prod. (accepted for publication). ii.1,7-Dihydroxy-3,5,8-trimethoxyxanthone (125() J. Nat. Prod. (accepted for publication). iii.1,5,8-Trihdroxy-3 methoxyxanthone (126) 1,5-Dihydroxy-3-methoxy-8-O-glcosylxanthone (127)

Phytochemical investigation on Primula denticulate have resulted in the isolation of the new flavone:

5,6-Dihydroxyflavone (128) J. Nat. Prod. (accepted for publication).

Extensive spectroscopic techniques such as EIMS, FDMS, FABMS, HRMS, UV, IR, FTIR, 1H and 13C-NMR (BB, DEPT, COSY-45°, J-resolved, NOE difference, hetero-COSY, HMBC and HMQC) were employed to elucidate the structures of the above compounds.

Download Full Thesis
1960.27 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
77.68 KB
2 1 General Introduction 1
249.51 KB
3 2 Rhazya Stricta 34
329.46 KB
  2.1 Introduction 35
  2.2 Results And Discussion 44
4 3 Alstonia Macrophylla 71
495.66 KB
  3.1 Introduction 72
  3.2 Results And Discussion 89
5 4 Neisosperma Oppositifiolia 125
238.12 KB
  4.1 Introduction 126
  4.2 Results And Discussion 128
6 5 Non-Alkaloidal Constituents From Rhazya Stricta, Swertia Cordata And Primula Denticulata 152
282.14 KB
  5.1 Rhazya Stricta 53
  5.2 Swertia Cordata 159
  5.3 Primula Deticulata 178
7 6 Experimental 182
271.93 KB
  6.1 General Experimental Conditions 183
  6.2 Rhazya Stricta 184
  6.3 Alstonia Macrophylla 187
  6.4 Neisosperma Oppositifolia 194
  6.5 Rhazya Stricta (Fruits) 200
  6.6 Swertia Cordata 203
  6.7 Primula Denticulata 208
8 7 References 209
283.81 KB
9 8 List Of Publications 237
17.67 KB