Liverwort Frullania franciscana Howe was found high on the allergic test scale by J. Mitchell of the Medical School of the University of British Columbia and co-workers. Frullanolide was isolated from Frullania tamarisci by J.D. Connoly and by G. Oisson and his co-workers.
The plant sample, collected in Oregon, was hand separated, confirmed, air dried and milled before the extractions were done. A Soxhlet extraction with ether and cold extractions with n-hexane and with ether were carried out. Ether is a better extraction solvent than n-hexane for cold extraction.
Column chromatography was used for the separation of the extract based on gradient elution from silica gel or aluminum oxide. Non-polar hydro-carbon sesquiterpenes and other hydrocarbons usually were eluted first. Frullanolide then was eluted.
Studies by thin layer chromatography on silica gel showed that none of the fractions was a pure component; therefore, further separations were done by thin layer chromatography and small-scale column chromatography. However, no satisfactory separation systems were found, except that frullanolide was isolated from the silica gel plate with cyclohexanel/ethyl acetate 80/20, Rf' = 25.8, which was very close to the reported value. An infrared spectrum of this was taken and used as supporting evidence.
An infrared spectrum of the first fraction from an aluminum oxide column showed that this was a reasonably pure fraction of hydrocarbons. By gas chromatography, eleven components were found in this fraction, and the percentage of the major component was calculated to be 97% by weight. Nuclear magnetic resonance and infrared spectra showed an exo-double bond with a 6-membered ring or larger. (I.R. : 3080 cm-1 ,1643 cm-1 ,888 cm-1, NMR δ 4.73) This fraction was then studied by means of a gas chr0matography-mass spectrometer, and the molecular weight of the main component of this fraction was 204. Kovats’ indices of the main component were taken by co-injection with 0-cedrene and ᵝ-bourbonene; these data, however, did not match any of the compounds listed.
Infrared analysis of the other fractions from the columns and from thin layer chromatography showed the presence of carbonyl groups. One of the carbonyl groups absorbed at about 1770 cm-1, characteristic of a y -lactone.
| Identifer | oai:union.ndltd.org:pdx.edu/oai:pdxscholar.library.pdx.edu:open_access_etds-3033 |
| Date | 01 January 1974 |
| Creators | Huang, Timothy Ta-E |
| Publisher | PDXScholar |
| Source Sets | Portland State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Dissertations and Theses |
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