Studies in the Field of Natural Products

Morrison, George A (1958) Studies in the Field of Natural Products. PhD thesis, University of Glasgow.

Abstract

The inter-relationship of the three mould metabolites atrovenetin, herqueinone, and norherqueinone has been elucidated by the discovery that deoxynorherqueinone (obtained by reduction of norherqueinone with zinc and acetic acid) is identical with atrovenetin. A study of the spectral properties of the three mould metabolites and their degradation products has been undertaken, from which it appeared that atrovenetin, deoxyherqueinone, xanthoherguein, and norxanthoherquein (the last two being obtained by acid hydrolysis of herqueinone and norhergueinone respectively) are all derivatives of 9-hydroxyperinaphthenone. This has been confirmed by suitable degradations, among which may be mentioned the nitric acid oxidation of xanthoherquein, norxanthoherquein, and atrovenetin to nitrococussic acid; and the oxidation of atrovenetin with alkaline hydrogen peroxide to a derivative of 2:7-dihydroxynaphthalic anhydride. The available data have all been correlated in terms of unique structures for atrovenetin, and many of its derivatives and degradation products, and for xanthoherguein. In particular, the compound, C15H14N2O9.H2O, obtained by previous workers by oxidising atrovenetin with concentrated nitric acid, has been reinvestigated, and assigned a phthalide type of structure consistent with all its chemical and physical properties (including its nuclear magnetic resonance spectrum). During the course of the work on atrovenetin, 2:7-dihydroxynaphthalic anhydride has been synthesised, and the spectra of this and seven other naphthalic anhydrides have been measured. A relationship between the amount of hydrogen-bonding in these compounds, and the positions of their infrared absorption bands in the carbonyl region has emerged. The molecular skeletons of norherqueinone and herqueinone follow from the work on atrovenetin. The possible positions of the methoxyl group in herqueinone have been reduced to two, as a result of suitable degradations. Possible structures for herqueinone and its derivatives and degradation products have been discussed. The structure of the interesting plant product, anisoxide, has been confirmed by the synthesis of anisoxide itself, and of several of its degradation products. The biogenesis of C5 isoprenoid side-chains attached to aromatic nuclei has been discussed, with special reference to atrovenetin and anisoxide.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1958
• Depositing User: Enlighten Team
• Unique ID: glathesis:1958-79289
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Mar 2020 11:04
• Last Modified: 05 Mar 2020 11:04
• URI: https://theses.gla.ac.uk/id/eprint/79289