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Title of Thesis

Fehmida Tasnim Baqai
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)
cestrum species, family solanaceae, c. diurnum, c. nocturnum, c. parqui, c. diurnum, c. nocturnum, c. aurunatiacum, c. parqui, nocturnoside a, nocturnoside b, diurnoside 1, parquisoside a, parquisoside b, saponins, sapogenin

The Cestrum species (Solanaceac) are ornamental plants with sporadic reports of their medicinal uses, C. diurnum, C. nocturnum and C. parqui, C. diurnum and C. nocturnum are cultivated in the gardens in Pakistan whereas C. aurunatiacum and C. parqui are naturalized in the Abottabad region only.

The present thesis describes the isolation and structure elucidation of five new saponins namely nocturnoside A, nocturnoside B, diurnoside 1, parquisoside A and parquisoside B, as well as a known saponin karatavioside A. A known sapogenin, yuccagenin was isolated in its native form.

The aglycone of the two saponins parquisoside A and parquisoside B is also a new sapogenin. It is a 24 B-hydroxy diosgenin and we have named it parquigenin.

Nocturnoside, A nocturnoside B, karatavioside A and yuccagenin were isolated from the leaves and stems of C. nocturnum. Diurnoside I was isolated from the leaves and stems of C. diurnum. Parquisoside A and parquisoside B were isolated from the aerial parts of C. parqui.

The plant parts of each of the species were extracted in methanol and evaporated to semi-dryness. These were partitioned between water and ethyl acetate, and then water and butanol.

The ethyl acetate extract of C. nocturnum yielded yuccagenin. Butanolic extracts contained the saponins. The saponins were purified by vacuum liquid chromatography, column chromatography and finally by high pressure liquid chromatography through semi-preparative RP-18 column or preparative thin-layer chromatography using procated silica gel, glass plates.

The structures of the compounds were elucidated with the help of chemical as well as spectroscopical analysis of each compound. The latter included extensive studies of various ID and 2D NMR spectral data.

Diverse pharmacological properties of the crude extracts or pure saponins were also investigated. The chemical names and structures of the six saponins and the sapogenin are given below:.

Download Full Thesis
2638.44 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
169.72 KB
2 1 Introduction 2
415.7 KB
  1.1 General Introduction 2
  1.2 Steroidal Saponins 6
  1.3 General Properties 12
  1.4 Biological and Pharmacological Activities of Steroidal Saponins 15
  1.5 Uses of Saponins in General 20
  1.6 Determination of molecular structure of steroidal saponins 24
3 2 Biosynthesis 44
337.85 KB
  2.1 Introduction 44
  2.2 Biosynthetic Classification of Natural Products 44
  2.3 Biosynthesis of triterpenes and steroids 48
  2.4 Biosynthesis of cholesterol 12 58
  2.5 Biosynthesis of C27 sapogenins 65
  2.6 Biosynthesis of saponins 72
4 3 Literature Survey 79
235.82 KB
  3.1 Introduction and background 79
  3.2 Pharmacological activity of cestrum specles A Oiterature Survey 83
  3.3 Mother nature at play 86
5 4 Results and Discussions 89
1291.14 KB
  4.0 Present Work 89
  4.1 Structure Elucidation of nocturnoside A 62 92
  4.2 Structure Elucidation of nocturnoside B 63 109
  4.3 Structure Elucidation of Saponin 64 128
  4.4 Structure Elucidation of Sapogenin 65 139
  4.5 Structure Elucidation of dicurnoside 66 153
  4.6 Structure Elucidation of Parquisoside A 67 170
  4.7 Structure Elucidation of Parquisoside B 68 187
6 5 Pharmacological Studies 209
88.37 KB
  5.1 Effect of the crude Extract of cestrum pargui 209
  5.2 N-Butonolic extract of C. nocturnum 214
  5.3 Brine Sharimp Lathality tests 216
7 6 Experimental 217
221.9 KB
  6.0 General Introduction 217
  6.1 Characterization of nocturnoside A 62 226
  6.2 Characterization of Compound 62 228
  6.3 Characterization of Karatovioside A 64 230
  6.4 Characterization of Yuccagenin 65 232
  6.5 Characterization of Diurnoside I 66 233
  6.6 Characterization of Parquisoside A 67 235
  6.7 Characterization of Parquisoside B 68 237
8 7 References 239
204.42 KB
  7.1 References 239
  7.2 List of Publications 257