I= ISOLATION, STRUCTURE BLUCIDATION AND BIOTRANSFORMATION STUDIES ON SECONDARY METABOLITES FROM WITHANIA SOMNIFERA AND RELATED PLANTS
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Title of Thesis
ISOLATION, STRUCTURE BLUCIDATION AND BIOTRANSFORMATION STUDIES ON SECONDARY METABOLITES FROM WITHANIA SOMNIFERA AND RELATED PLANTS

Author(s)
Sammer Yousaf
Institute/University/Department Details
University of Karachi, Pakistan
Session
2006
Subject
Chemistry
Number of Pages
183
Keywords (Extracted from title, table of contents and abstract of thesis)
structure blucidation, withania somnifera, secondary metabolites, antilesihmanial activity , physalis minima, bioactive plant metabolite

Abstract
This Ph.D thesis comprises of three parts. Part A deals with the phytochemical studies of Withania somnifera (L. Dunal), part B describes the phytochemical investigation on physalis minima Linn., while part C focuses on the biotransformation of physalin H, a bioactive plant metabolite.

Part A the phytochemical studies on the chloroform extract of withania somnifera (L. Dunal), have afforded two new and three known withanolides. The cholinesterase inhibiting activity of these compounds was evaluated by one of our colleagues, Dr. Sarfraz Ahmad Nawaz, in the enzyme inhibition laboratory of the H.E. J. Research institute of Chemistry, and all compounds were found to possess varying degree of cholinesterase inhibitory potential in a concentration €“ dependent manner.

New withanolides isolated from withania somnifera

Chem, pharm. Bull., 52 (11), 1358 (2004).

Known withanolides Isolated from withania somnifera

Part B of the thesis contains details of the isolation of six new and three known antieishmanial physalins from the chloroform extracts of physalins minima Linn. (var. indica). The antileishmanial activity of these compounds were evaluated by Ms. Samreen in the Bioassay section of the H.E. J. Research Institute.

New Compound Isolated from Physalis minima

Chemistry and Biodiversity, 2, 1164 (2005).

Natural Product Research, 2006 (Accepted).

Known Compounds Isolated from Physalis minima

All compounds were founds to possess significant antileishmanial activities with the IC50 values between 0.92 to 38.9 ug / ml, by using amphotericin as the standered drug (IC50=0.12 ug / ml ).

Part C focuses on the biotransformation of physalin H (isolated during the phytochemical investigation on physalis minima) by inculbation with Rhizopus stolonifer and cunninghamella elegans, results in two new (95 and 96) and one known metabolite 84. These metabolites were screened for their antileishmanial activities.

Chem. Pharm. Bull., 52 (11), 1358 (2006).

The structures of compounds, isolated from the withania somnifera and physalis minima together with transformed metabolites, were elucidated through spectroscopic methods such as UV, IR, 1H €“ and 13C-NMR and 2D-NMR techniques (COSY, NOESY, NOE, HMBC, HMQC).

Download Full Thesis
11219.24 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 1 General Introduction 1
192.77 KB
2 2 Study On The Secondary Metabolites Of Withania Somnifera (L.Dunal) 5
3124.33 KB
  2.1 Introduction 5
  2.2 Results And Discussion 31
3 3 Studies On The Secondary Metabolites Of Physalis Minima Linn. (Var.Indica) 59
3343.74 KB
  3.1 Introduction 59
  3.2 Results And Discussion 69
  3.3 Antilesihmanial Activity Of Compounds Isolated From Physalis Minima 110
4 4 Biotransformation Of Physalin H (83), Isolated From Physalis Minima Linn. (Var. Indica) 118
827.36 KB
  4.1 Introduction Of Biotransformation 118
  4.2 Microbial Transformation Of Physalins 119
  4.3 Results And Discussion 121
  4.4 Antileishmanial Activity Of Transformed Phsalins 132
5 5 Experimental 134
2114.36 KB
  5.1 General Experimental Conditions 134
  5.2 Withania Somnifera 135
  5.3 Physalis Minima 143
  5.4 Biotransformation Of Physalin 157
  5.5 Methods Of Biological Assays 161
6 6 References 167
1011.62 KB
  6.1 Glossary 178
7 7 List Of Publications
46.08 KB