I= STUDIES IN THE CHEMICAL CONSTITUENTS OF ALSTONIA SPECIES LAURENCIA PINNATIFIDA AND RELATED MARINE ORGANISMS
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Title of Thesis
STUDIES IN THE CHEMICAL CONSTITUENTS OF ALSTONIA SPECIES LAURENCIA PINNATIFIDA AND RELATED MARINE ORGANISMS

Author(s)
Syed Ali Abbas
Institute/University/Department Details
University of Karachi/ H.E.J. Research Institute of Chemistry
Session
May 1990
Subject
Chemistry
Number of Pages
197
Keywords (Extracted from title, table of contents and abstract of thesis)
alstonia species, laurencia pinnatifida, marine organisms, alstonia macrophylla, marine animals, zoanthid , aplysia juliana, angasiol acetate, diterpenoid

Abstract
The thesis is divided into two parts. The first part describes the studies on the chemical constituents of Alstonia macrophylla and alstonia scholaris. The second part deals with the natural products of marine origin namely marine alga, Laurencia pinnatifida and marine animals zoanthid (an unidentified species) and aplysia Juliana.

Investigation of the alkaloidal contents of alstonia macrophylla led to the isolation of two new alkaloids along with two others which had been previously reported from other sources 1. Alstonmide (33) J.Nat. Prod., accepted fro publication. 2. Demethoxyalstonamide (40) Prod., accepted fro publication. 3. Vincorine (41) Planta medica submitted for publication 4. 3,4,5, -Trimethoxybenzoylvincamajine (42) Planta medica submitted for publication

The leaves of Alstonia scholaris were investigated which led to the isolation of a new alkaloid along with a previously reported one: 5. 10,20 –Z-vallesamine (43) Heterfocycles, 26 (2) 413 (1987) 6. 19,20-E-Vallesamine (48) Heterocycles, 26 (2) 413 (1987)

The second part of the thesis comprises studies on the chemistry of flora and fauna of the Arabian sea. Chemical investigation of Laurencia pinnatifida, Aplysia Juliana and an unidentified species of Zoanthid led to the isolation and structure elucidation of the following compounds. 1. Pinnatacane (49) Phytochemistry 27 (12), 3879 (1988) 2. Rearranged chamigrene acetate (56) Phytochemistry, submitted for Publication. 3. Pinnatifene (57) Phytochemistry, submitted for Publication. 4.Angasiol acetate (62) Phytochemistry, Accepted for Publication

Investigation on the sea hare Aplysia Juliana led to the isolation of angasiol acetate. The same compound has been isolated by us from Laurencia pinnatifida: Angasiol acetate (62) J. Nat. Prod. Submitted for Publication.

An unidentified species of the marine animal Zoanthid was investigated which led to the isolation of a new alkaloid along with two previously reported from other sources. These belong to a new class of alkaloids: 1. Zoanthaminone (67) Tetrahedron lett., 30 (49) 6825 (1989) 2. Zoanthamine (68) Teterahedron lett., 30 (49( 6825 (1989) 3. Zoanthamide (69) Tetrahedron lett., 30 (49) 6825 (1989)..

Modern spectroscopic techniques, including two dimensional NMR experiments, (COSY-45, 2D J-resolved, NOESY, hetero-COSY, COLOC) were employed to elucidate the structure of the above mentioned compounds. BB and DEPT experiments were carried out to determine the multiplicities of the carbon atoms. The stereochemistry at various asymmetric centres was established by noe measurements. The absolute configuration of some compounds was determined through X-ray crystallographic techniques.

Download Full Thesis
1379.97 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
77.94 KB
2 1 Part A : General Introduction 1
40.12 KB
3 2 Indole Alkaloids 2
91.5 KB
  2.1 Introduction 2
  2.2 Biosynthesis 7
4 3 Isolation And Structure Elucidation Of Alkloids From Alstonia Macrophylla 19
237.58 KB
  3.1 Introduction 19
  3.2 Results And Discussion 19
5 4 Isolation And Structure Elucidation Of Alkaloids From Alstonia Scholaris 50
105.78 KB
  4.1 Introduction 50
  4.2 Results And Discussion 51
6 5 Experimental Part- A 63
79.86 KB
  5.1 Isolation Of Alkaloids From The Leaves Of Alstonia Macrophylla 63
  5.2 Isolation Of Alkaloids Form The Leaves Of Alstonia Scholaris 68
7 6 Part B: Marine Natural Products 72
20.12 KB
  6.1 Introduction 72
8 7 Isolation And Structure Elucidation Of Metabolites From Laurencia Pinnatifida 74
365.11 KB
  7.1 Introduction 74
  7.2 Results And Discussion 85
9 8 Isolation And Structure Elucidation Of A Diterpenoid From Aplysia Juliana 122
131.49 KB
  8.1 Introduction 122
  8.2 Results And Discussion 122
10 9 Isolation And Structure Elucidation Of Alkaloids From An Unidentified Species Of Zoanthid 139
188.42 KB
  9.1 Introduction 139
  9.2 Results And Discussion 139
11 10 Experimental Part B 161
121.2 KB
  10.1 Isolation Of Metabolites From Laurencia Pinnatifida 161
  10.2 Isolation Of Diterpenoid From Aplysia Juliana 166
  10.3 Isolation Of Alkaloids From Zoanthids 168
12 11 References 174
185.39 KB