Studies in Natural Products

Dagli, Selma (2002) Studies in Natural Products. PhD thesis, University of Glasgow.

Abstract

This thesis consists of eleven chapters and deals with phytochemical investigations of several liverwort species together with Piper chaba and Inula klengii. The first chapter gives a general introduction dealing with the nature of secondary metabolites and the skeletal types found in the Hepaticae. This is followed by an examination of the chemical constituents found in the liverwort Scapania undulata. Three known compounds were isolated from this liverwort and these are: (-)-ent-longipinanol, (-)-longiborneol, and an amorphane/muurolane(cadinane) type sesquiterpenoid, which probably came from the liverwort Marsupella aquatica mixed with S. undulata in their growing habitat. The third chapter consists of an investigation of the extract of a flowering plant called Piper chaba, sent to us by a Chinese colleague. Four known compounds, pipeline, pipernonaline, guineensine and the isobutylamide of 13-(3,4-methylenedioxyphenyl)undeca-2,4,12-trienoic acid were isolated. The following chapter examines the chemical constituents of the Scottish liverwort Conocephalum conicum, which gave 3,4'-dihydroxybibenzyl and 3,4-dimethoxystyrene. The metabolites of Nardia scalaris form the subject matter of Chapter 5. Three known ent-kaurane diterpenoids, (15S)-ent-kaur-16-en-15-y1 hydrogen malonate, (15R)-ent-kaur-16-en-15-ol and ent-kaur-16-en-15alpha,3beta-diol have been found in this liverwort. The chemical constituents of the liverwort Trichocolea tomentella are revealed in the next chapter. Four known compounds, deoxytomentellin, trichocolein, tomentellin, isotomentellin and two new compounds Methyl 4[7-hydroxy-3,7-dimethy1-2,5-octadienyloxy]-3-methoxybenzoate, and Methyl 4[5-hydroxy-3,7-dimethy1-2,6-octadienyloxy1-3-methoxybenzoate were isolated. Chapter 7 deals with the constituents of the Taiwanese liverwort Scapania robusta, which afforded ent-spathulenol, found in many liverworts. The following chapter examines the metabolites of the extract of the flowering plant Inula klengii. Two new sesquiterpene lactones, 8beta-angeloyloxy-14-acety1-1(10),4,11(13)-germacratrien-12,6alpha-olide, and 8beta-angeloyloxy-14-hydroxy-1(10),4,11(13)-germacratrien-12,6alpha-olide as well as the known lactones melampolide and ovatifolin were isolated. Chapter 9 deals with the constituents of Marsupella aquatica, which gave the known sesquiterpenoids marsupellone, acetoxymarsupellone, 9,11alpha,14-triacetoxymarsupellone, 9,11beta,14 triacetoxymarsupellone, and marsupellol. Chapter 10 examines the metabolites of Scottish liverworts Herbertus dicramus and H. stramineus. Two sesquiterpenoids, alpha- and beta-herbertenols, were present in both liverworts, however a new herbertane-type sesquiterpenoid has been isolated from Herbertus stramineus. The next chapter considers the chemical constituents of Scottish Porella platyphylla, which afforded pinguisanin and perrottetianal A, and two French Porella species, one of which afforded a new sesquiterpenoid, a derivative of pinguisanin. The structures were determined mainly using one and two dimensional NMR experiments. The final chapter consists of an investigation of the extract of Miliusa velutina from the Annonaceae family. Four acetogenin-related compounds, three of which are new, have been identified in the extract of this plant by spectroscopic and GCMS analysis.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: Joseph D Connolly
• Keywords: Organic chemistry
• Date of Award: 2002
• Depositing User: Enlighten Team
• Unique ID: glathesis:2002-76054
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Dec 2019 09:15
• Last Modified: 19 Dec 2019 09:15
• URI: https://theses.gla.ac.uk/id/eprint/76054