UBC Theses and Dissertations
Thiarubrine production in roots and root cultures of Ambrosia chamissonis Ellis, Shona Margaret
Ambrosia chamissonis (Asteraceae) provides antibiotic sulphur heterocyclic polyynes known as thiarubrines and thiophenes. They occur in all parts of the plant, especially in the roots and can be visualized in hand sections. Methods were developed for their isolation, purification and quantification. Plants were collected from various locations in B.C. and found to have different thiarubrine profiles. A new thiarubrine (3-(1-propyny1)-6-(6-hydroxyhex-3-yn-1yny1)-1,2-dithiacyclohexadiene) and thiophene (2-(1-propyny1)-6-(6-hydroxyhex-3-yn-1yny1)-thiophene) were identified from roots and root cultures. Transgenic and non-transgenic root cultures were generated and shown to produce the same compounds as occur in natural roots. Quantitative chemical profiles of the cultured roots matched those of roots which had little secondary growth. Elicitation, with fungal preparations, did not enhance the over-all thiarubrine concentration, but the content of a more fungicidal thiarubrine was enhanced at the expense of a less active, but predominant thiarubrine. Administration of biosynthetic precursors did not have any effect on thiarubrine production. Antibiotic testing indicated that the thiarubrines are toxic against a number of fungi and, to a lesser degree, bacteria.
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