| Autor: |
Sadgrove NJ; Jodrell Science Laboratory, Royal Botanic Gardens Kew, Richmond TW9 3DS, UK., Padilla-González GF; Jodrell Science Laboratory, Royal Botanic Gardens Kew, Richmond TW9 3DS, UK., Green A; Jodrell Science Laboratory, Royal Botanic Gardens Kew, Richmond TW9 3DS, UK., Langat MK; Jodrell Science Laboratory, Royal Botanic Gardens Kew, Richmond TW9 3DS, UK., Mas-Claret E; Jodrell Science Laboratory, Royal Botanic Gardens Kew, Richmond TW9 3DS, UK., Lyddiard D; School of Science and Technology and School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia., Klepp J; School of Science and Technology and School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia., Legendre SVA; School of Science and Technology and School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia., Greatrex BW; School of Science and Technology and School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia., Jones GL; School of Science and Technology and School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia., Ramli IM; School of Science and Technology and School of Rural Medicine, University of New England, Armidale, NSW 2351, Australia., Leuner O; Department of Crop Sciences and Agroforestry, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic., Fernandez-Cusimamani E; Department of Crop Sciences and Agroforestry, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic. |
| Abstrakt: |
Australia's endemic desert shrubs are commonly aromatic, with chemically diverse terpenes and phenylpropanoids in their headspace profiles. Species from the genus Eremophila (Scrophulariaceae ex. Myoporaceae) are the most common, with 215 recognised taxa and many more that have not yet been described, widely spread across the arid parts of the Australian continent. Over the years, our research team has collected multiple specimens as part of a survey to investigate the chemical diversity of the genus and create leads for further scientific enquiry. In the current study, the diversity of volatile compounds is studied using hydrodistilled essential oils and leaf solvent extracts from 30 taxa. Several rare terpenes and iridoids were detected in chemical profiles widely across the genus, and three previously undescribed sesquiterpenes were isolated and are assigned by 2D NMR- E -11(12)-dehydroisodendrolasin, Z -11-hydroxyisodendrolasin and 10-hydroxydihydro-α-humulene acetate. Multiple sampling from Eremophila longifolia , Eremophila arbuscular , Eremophila latrobei , Eremophila deserti , Eremophila sturtii , Eremophila oppositifolia and Eremophila alternifolia coneys that species in Eremophila are highly chemovariable. However, taxa are generally grouped according to the expression of (1) furanosesquiterpenes, (2) iridoids or oxides, (3) mixtures of 1 and 2, (4) phenylpropanoids, (5) non-furanoid terpenes, (6) mixtures of 4 and 5, and less commonly (7) mixtures of 1 and 5. Furthermore, GC-MS analysis of solvent-extracted leaves taken from cultivated specimens conveys that many heavier 'volatiles' with lower vapour pressure are not detected in hydrodistilled essential oils and have therefore been neglected in past chemical studies. Hence, our data reiterate that chemical studies of the genus Eremophila will continue to describe new metabolites and that taxon determination has limited predictive value for the chemical composition. |
