Selective Extraction of Bioactive Phenylethanoids from Digitalis obscura
MetadataShow full item record
AuthorQuílez Del Moral, José Francisco; Pérez Rodríguez, Álvaro Adrián; Segura Navarro, María José; Galisteo Pretel, Alberto; Fernández Barrero, Alejandro
Selective extractionNatural productsPesticidesAntifeedantNematicidal
Quílez del Moral, J.F.; Pérez, Á.; Navarro, M.J.S.; Galisteo, A.; Gonzalez-Coloma, A.; Andrés, M.F.; Barrero, A.F. Selective Extraction of Bioactive Phenylethanoids from Digitalis obscura. Plants 2021, 10, 959. https:// doi.org/10.3390/plants10050959
SponsorshipMINISTERIO DE ECONOMÍA Y COMPETITIVIDAD; PID2019-106222RB-C32/SRA (State Research Agency, 10.13039/501100011033); PID2019- 106222RB-C31/SRA (State Research Agency, 10.13039/501100011033); ERASMUS + N◦2018-1-FR01- KA202-047892 Biocontrol E Training (BET); Unidad Asociada UGR-CSIC Bioplaguicidas: Biotecnología, síntesis y diversidad química
Cardenolide-free extracts from Digitalis obscura showed significant antifeedant effects against the aphid Myzus persicae and this activity correlated with their phenylethanoid content. The content in phenylethanoids of Digitalis obscura has been studied. Maceration of the aerial parts of D. obscura was used for the selective extraction of the natural compound rengyolone (1) and the aglycone of cornoside (compound 3). Pure rengyolone (1) can be obtained from D. obscura in approximately 90% purity from fresh plant from the CHCl3 soluble fraction of the ethanolic extract (0.8% yield). The ethanol extraction of freshly collected D. obscura showed the presence of compound 3 as the only phenylethanoid. Compound 3 was proven to easily evolve to rengyolone. Due to this instability, and although its presence in plants has been previously reported, the spectroscopical data of 3 are reported herein for the first time. Selective mono-acetylation of compound of 3 led to the active natural compound hallerone (5). The aphid antifeedant (against Myzus persicae) and nematicidal (against root-knot nematode Meloidogyne javanica) activities of these compounds have been evaluated. Here we report for the first time on the aphid antifeedant effects of 1, 3, and 5. Additionally, the nematicidal activity of hallerone (5) is described here for the first time.