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Title of Thesis

Wazir Shaikh
Institute/University/Department Details
University of Karachi/ Department of Botany
Number of Pages
Keywords (Extracted from title, table of contents and abstract of thesis)
brown algae, colpomenia sinuosa (mertens ex roth) derbes et solier, dictyoperis austalis (sonder)askenasy, dictyota dichotoma (hudson) lamouroux, d. dumosa borgesen, d. hauckiana nizamuddin, d. indica sonder, d. maxima zanardini, hincksia mitchelliae (harvey) silva, jolyna laminarioides guimaraes in guimeraes et al., padina tetrastromatica hauck, sargassum tenerrimum j. agardh, spatoglossum variabile figari et de notaris, stoechospennum marginatum (c. agardh) kutzing, stokeyia indica thivy et doshi

Fourteen commonly occurring species of marine benthic algae i.e. Colpomenia sinuosa (Mertens ex Roth) Derbes et Solier, Dictyoperis austalis (Sonder)Askenasy, Dictyota dichotoma (Hudson) Lamouroux, D. dumosa Borgesen, D. hauckiana Nizamuddin, D. indica Sonder, D. maxima Zanardini, Hincksia mitchelliae (Harvey) Silva, Jolyna laminarioides Guimaraes in Guimeraes et al., Padina tetrastromatica Hauck, Sargassum tenerrimum J. Agardh, Spatoglossum variabile Figari et De Notaris, Stoechospennum marginatum (C. Agardh) Kutzing and Stokeyia indica Thivy et Doshi, belonging to all the three classes of Phaeophyta, have been collected from the coastal areas near Karachi (Pakistan) and investivated taxonomically as well as phycochemically. Although, all of them are taxonomically known species, but Dictyota dichotoma, D. dumosa, D. hauckiana, D. indica, D. maxima, Jolyna laminarioides. Padina tetrastromatica, Sargassum tenerrimum and Stokeyia indica have been described taxonomically for the first time from the coast of Pakistan

A variety of saturated and unsaturated fatty acids were detected in the extracts of these algal species and analysed as methyl esters qualitatively as well as quantitatively through GLC and GC-MS techniques. Several sterols, terpenes, polyols and certain metabolites have been isolated from those seaweeds, purified and their structures elucidated chemically through standard spectroscopic methods e.g. El-FAB-, FD-, GC- & HR-MS and IR, 1H- & 13C-NMR. Certain new and novel compounds have been isolated from them: e.g. dicdichane from Dictyota dichotoma; hauckiosterol from Dictyota hauckiana and Spatoglossum variabile; dictinol, dictindiol, dictintriol, amijiol and sargasterol from dictyota indica; Padinolide from Colpomernia sinuosa and Padina tetrastromatica; 19-acetoxy-5 ®, 15, 18, (R & S)- trihydroxy-spata-13, 16 (E)-diene from spatoglossum variabile and Stoechospermum marginatum; 5 ® 15, 18, (R & S), 19-tetrahydroxy-spata-13, 16 (E)-diene, 5 ®, 18-dihydroxy-spata-13, 16 (E)-diene and 5 ® 16-dihydroxy-spata-13, 17-diene from Stoechospermum marginatum; stigasta-5, 23-diene-3β-ol from Jolyna laminarioides; and loliolide and stokerine from Stockeyia indica

The hauckiosterol among sterols, dictinol, dictindiol and dictintriol among diterpenes and Padinolide, dicdichane and stokerine among metabolites were the new compounds isolated for the first time from a natural source. All the natural products described, have been reported for the first time from the corresponding algal species. The four tricyclic diterpenoids isolated from Stochospermum marginatum have also been tested against three gram positive and six gram negative bacteria as well as six pathogenic fungi, and were found to exhibit strong antimicrobial activity

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents/ Abstract 0
279.08 KB
2 1 Introduction 27
94.62 KB
3 2 Materials And Methods 34
85.96 KB
  2.1 Algal Material 34
  2.2 Taxonomic Studies 34
  2.3 Isolated Of Fatty Acids 35
  2.4 Extaction Of Sterols 35
  2.5 Separation Of Terpenes 36
  2.6 Detection Of Polyols 36
  2.7 Isolation Of Halogenated Compounds 37
  2.8 Extraction Of Metabolites 37
  2.9 Instrumentation 37
4 3 Results And Discussion 41
1804.62 KB
  3.1 Hincksia Mitchelliar (Harvey 1852) Harvey 1987 43
  3.2 Dictyopteris Austrialis ( Sonder 1853) Askenasy 1888 56
  3.3 Dictyota Dichotoma (Hudson 1762) Lamouroux 1809 66
  3.4 Dictyota Dumosa Borgesen 1935 85
  3.5 Dictyota Hauckiana Nizamuddin 1975 92
  3.6 Dictyota Indica Sonder 1859 102
  3.7 Dictyota Maxima Zanardini 1872 119
  3.8 Padina Tetrastromatica Hauck 1887 132
  3.9 Spatoglossum Variabile Figari Et De Notaries 1853 147
  3.10 Stoechospermum Marginatum (C. Agardh 1824) 158
  3.11 Colpomenia Sinuosa ( Mertens Ex Roth 1806) 174
  3.12 Jolyna Laminarioides Guimaraes In Guimaraes Et Al. 1986 189
  3.13 Sargassum Tenerrimum J. Agardh 1848 207
  3.14 Stokeyia Indica Thivy Et Doshi 1966 218
5 4 Concluding Remarks 234
137.11 KB
  4.1 Taxonomic Studies 234
  4.2 Phycochemical Investigation 237
6 5 Acknowledgements 248
24.22 KB
7 6 Literature Cited 250
697.4 KB