Chemical comparison of liverworts using NMR spectroscopy

摘要

The lipophilic constituents of liverworts have been studied using ~1H NMR spectroscopy by extracting small samples of the liverworts with the NMR solvent CDCl_3. One application of the technique has been to compare samples of Adelanthus decipiens of different origin, including herbarium specimens; of particular interest is a re-investigation, using a voucher specimen, of material that was the subject of a GC-MS study in 1981. The strength of the technique is demonstrated by the finding that compounds previously thought to be eudesmanolides are actually wettsteins A and B, two of the ten highly oxygenated naphthalenes and acetophenones identified in Adelanthus decipiens. The ~1H NMR spectrum of the extract of one sample of Cryptothallus mirabilis showed that one compound was predominant in the extract; this compound is 15-acetoxypinguisone, a simple derivative of the sesquiterpene ketone first isolated from Aneura pinguis, a fellow member of the Aneuraceae.