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Title of Thesis

Muhammad Ali Versiani
Institute/University/Department Details
University of Karachi/ H.E.J Research Institute of Chemistry
Number of Pages
Keywords (Extracted from title, table of contents and abstract of thesis)
bombax ceiba, cuscuta reflexa, terpeniods, steroids, cardiotonic glycosides, aromatic compounds, falvonoids

The PhD work presented in this thesis consists of two parts. The part A describes the studies in the chemical constituents of Bombax ceiba and part B represents the bioassay directed isolation and structure elucidation studies in the chemical constituents of Cuscuta reflexa. A brief review on the biosynthesis of terpeniods, steroids, cardiotonic glycosides, aromatic compounds and falvonoids is also included

Part-A: This part describes the review of earlier researches in the constituents of B. Ceiba and a brief discussion of the present work. Dried leave extracts of the plant was subjected to chemical investigation which led to the isolation of three new (I-III) and one known compound mangiferin (IV) which was obtained in high yield. These compounds are listed below

New constituents from B. Ceiba: 4-C-B-D-Glucopyranosyl-1,3,6,8-tetrahydroxy-7-o-(4”-hydroxybenzoyl)-9H-xanthen-9-one (I) 2-C-B-D-Glucopyranosyl-1,6,7-trihydroxy-3-o(4”-hydroxybenzoyl)-9H-xanthen-9-one (II) 4-C-B-D-Glucopyranosyl-1,6,8-trihydroxy-3,7-di-o-(4”-hydroxybenzoyl)-9H-xanthen-9-one (III)

Constituents isolated for the first time from B. Ceiba: 4, 2-C-B-D-Glucopyranosyl-1,3,6,7-tetrahydroxy-9H-xanthen-9-one, Mangiferin (IV) In conformity to the structure IV, mangiferin afforded octa (V), hepta (VI), penta (VII) and tetra (VIII) acetylated derivatives, on reaction with acetic anhydride and pyridine. Antimicrobial studies showed that IV, V and VI are active against a few Gram positive and Gram negative bacteria and some fungi. Mangiferin (IV) has significant potency as hypotensive agent and exhibited hypoglycaemic activity and possessed on toxicity. Moreover, a known compound lupeol (IX) has been isolated from the petroleum ether extract of the stem bark of B. ceiba in very large amount

Compounds IV and V were found to be inactive in cytotoxic (cancer cell panel of 60 lines) and anti-HIV tests carried out in NCI, (NIH), Bethesda, USA.

Extensive spectral .studies UN, IR, EIMS, NMR (H and C) and 2D-NMR (COSY-45, NOESY, HMQC/Hetro COSY, HMBC/COLOC and J-resolved experiments as well as chemical transformation were employed to elucidate the structures of all the isolated compounds.

Part-B.4This part provides a review of the earlier contributions made in the chemistry and pharmacology of parasitic plant Cuscuta reflexa and a brief discussion of the present work, with reference to the bioassay directed isolation of anti-cancer and other compounds from the ethanolic extract of C. reflexa. This work led to the isolation of twenty six compounds which were characterized through the spectral studies and chemical transformations. One (II) of them is a new constituent and the remaining twenty five (I, III-XXVI) are known compounds of which twelve are new from the plant C. reflexa. They are listed below.

New constituent from C. reflexa, 1. 21-Hydroxy odoroside H (II) Constituents isolated for the first time from C. reflexa

2. Odoroside H (I)

3. Neritaloside (III)

4. Strospeside (IV)

5. Gitoxigenin (V)

6. N-trans feruloyl tyramine (VI)

7. N-cis Feruloyl tyramine (VII)

8. 7-Hydroxy-6,8-dimethoxy coumarin (X)

9. Ursolic acid (XI)

10. B-Sitosterol glucoside (XII)

11. 4-O-p-Coumaroyl-O-glycoside (XIII) (A+B)

12. Methyl cinnamate (XXII)

13. Dihydroajugapitin (XXVI)

Known constituents from C. reflexa

14. Ethyl 3-(3,4-dihydroxy phenyl)-2-propenoate (VIII)

15. 6,7,8-Trimethoxy coumarin (IX)

16. Nonacosane (XIV)

17. Octacosane (XV)

18. Heptacosane (XVI)

19. Hexacosane (XVII)

20. Pentacosane (XVIII)

21. Tetracosane (XIX)

22. Triacosane (XX)

23. Ferulic acid (XXI)

24. 3,5-Dicaffeoyl quinic acid (XXIII)

25. 4,5-Dicaffeoyl quinic acid (XXIV)

26. B-Sitosterol (XXVI)

Isolation and fractionation on the active of the plant, employing anti-cancer assay against a panel of 60 cell lines, led to the isolation of compounds I, III and IV which were found to be very potent anti-cancer agent. Compound I showed positive hollow fiber test and has been selected for in vivo xenograft testing. The evaluation of anticancer activity of extract, fractions and pure compounds have been done in NCI (NIH), Bethesda USA. The work is unpublished and after more experiments, it will be patented. During the course of this chemical and biological endeavor host plant effect on the constituents of C. reflexa was also observed and discussed in the end.

Download Full Thesis
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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
131.53 KB
2 1 General Introduction 6-13
130.47 KB
3 2 Biosynthesis 14-72
717.56 KB
4 3 Part-A-Studies In The Chemical Constituents Of Bombax Ceiba Linn 73-89
303.08 KB
  5.1 Introduction 73-89
5 4 Results And Discussions 90-127
675.5 KB
6 5 Experimental 128-142
295.32 KB
7 6 References 143-153
212.33 KB
8 7 Part-B Bioassay Directed Isolation And Structural Studies In The Chemical Constitutents Of Cuscuta Reflexa Roxb 156-187
599.78 KB
  7.1 Introduction 156-187
9 8 Results And Discussions 188-271
1291.25 KB
10 9 Experimental 272-290
217.48 KB
11 10 References 291-305
149.2 KB
12 11 Appendix 291-305
147.41 KB
  11.1 List Of Tables 307-311
  11.2 List Of Schemes 312-313
  11.3 List Of Compounds 314-316
  11.4 List Of Publications 317-318