I= ISOLATION AND CHARACTERIZATION OF BIOACTIVE NATURAL PRODUCTS FROM STOCKSIA BRAUHICA
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Title of Thesis
ISOLATION AND CHARACTERIZATION OF BIOACTIVE NATURAL PRODUCTS FROM STOCKSIA BRAUHICA

Author(s)
Sadia Bader
Institute/University/Department Details
H.E.J Research Institute of Chemistry/ University of Karachi
Session
2006
Subject
Chemistry
Number of Pages
124
Keywords (Extracted from title, table of contents and abstract of thesis)
stocksia brauhica, sapindaceae, oleanane glycoside, flavonoid glycoside, brauenesaponin a, brauhenefloroside c, brauhenefloroside 0, brauhenefloroside e, brauhenefloroside f

Abstract
The work embodied in this dissertation is mainly concerned with the isolation and characterization of chemical constituents from a terrestrial plant. The isolated compounds whether new or previously reported in the literature, were characterized by using various sophisticated spectroscopic techniques available at this institute.

The dissertation is divided in two parts dealing with the chemistry of Stocksia brauhica. In Part A the chemical analysis of fruits of Stocksia brauhica is described. Part B deals with the chemical analysis of petals of Stocksia brauhica (Sapindaceae).

Chemical analysis of fruits of Stocksia brauhica The studies on fruits resulted in the isolation and characterization of five new constituents, out of these, one compound contain oleanane glycoside skeleton and four have flavonoid glycoside skeleton. In addition to these new constituents, four known compounds have also been isolated and identified from this species. The new constituents isolated from fruits include: brauenesaponin A (54), brauhenefloroside C (55), brauhenefloroside 0 (56), brauhenefloroside E (57) and brauhenefloroside F (58).

The known compounds isolated from the fruits are oleanolic acid (50), lupeol (51), β-sitosterol (52) and β-sitosterolglycoside (53).

Compounds 57 and 58 were subjected to radical scavenging assay to evaluate the antioxidant potential using two complimentary assays, DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) scavenging assay and NO (Nitric oxide radical) scavenging assay. Both of these compounds were inactive against DPPH and having moderate activity against NO.

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Chemical analysis of petals of Stocksia brauhica Part-B deals with the chemical studies on S. brauhica. The present work has resulted in the isolation of three known compounds. These compounds include, 3-0-glucose-3',4',S,7-tetrahydroxyflavone (59), 3-0-rutinosyl-4',S,7,trihydroxy flavone (60), 3-0-rutinosyl-3',4',S,7-tetrahydroxy flavone (61). Compound 60 and 61 were subjected to radical scavenging assay to evaluate the antioxidant potential of test samples using two complimentary in vitro bioassays, DPPH (l,1-Diphenyl-2-picrylhydrazyl radical) scavenging assay and NO (Nitric oxide radical) scavenging assay. Both these compounds are active against DPPH and NO.

Download Full Thesis
2797.64 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
293.8 KB
2 1 Introduction 1
490.14 KB
  1.1 Sapindaceae 2
  1.2 Saponins 3
  1.3 Flavonoids 11
  1.4 Antioxidant 16
3 2 Biosynthesis 19
363.81 KB
  2.1 Biosynthesis Of Triterpenoid 19
  2.2 Biosynthesis Of Flavonoids 26
  2.3 Individual Steps Of Flavonoid Classes 29
4 3 Literature Review On S. Brauhica 35
56.07 KB
5 4 Present Work 38
1180.83 KB
  4.1 Present Work 38
  4.2 Chemical Constituents From Fruits Of Stocksia Brauhica 38
  4.3 Chemical Constituents From Petals Of S. Brauhica 82
6 5 Experimental 95
375.5 KB
  5.1 Experimental 95
  5.2 General Note 95
  5.3 Chromatography 96
  5.4 Stocksia Brauhica 96
  5.5 Material For Antioxidant Activity 113
7 6 References 117
210.61 KB