Isolation and Chemotaxonomic Implications of Tenelloside, a Novel Unusual C-Glycosyl Flavanone from Phyllanthus tenellus Roxb. in Tenerife Island

Phyllanthus is a large genus of the Euphorbiaceae family, which has been widely used in traditional medicine. The current study reports the isolation of an unusual C-glycosyl flavonoid, named tenelloside, from Phyllanthus tenellus Roxb., a non-endemic plant present in Canary Islands. The chemical structure of this secondary metabolite was established employing combined spectrometric and spectroscopic techniques, including 1D and 2D NMR experiments and mass spectrometry. The absolute stereochemical configuration was determined via the comparison of experimental and calculated electronic circular dichroism spectra. In our previous work, another C-glycosylated bioactive product was isolated from another Phyllanthus species, suggesting that this class of compounds can be produced in a genus-specific manner in different geographic regions. This work represents another important report for direct future studies on the biological and chemotaxonomic potential of C-glycosylated products of the Phyllanthus genus.