Assignment Through Chiroptical Methods of The Absolute Configuration of Fungal Dihydropyranpyran-4-5-Diones Phytotoxins, Potential Herbicides for Buffelgrass (<i>Cenchrus ciliaris</i>) Biocontrol
Ernesto Santoro,
Giuseppe Mazzeo,
Giulia Marsico,
Marco Masi,
Giovanna Longhi,
Stefano Superchi,
Antonio Evidente,
Sergio Abbate
Affiliations
Ernesto Santoro
Department Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
Giuseppe Mazzeo
Department Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
Giulia Marsico
Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
Marco Masi
Department of Chemical Sciences, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy
Giovanna Longhi
Department Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
Stefano Superchi
Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
Antonio Evidente
Department of Chemical Sciences, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy
Sergio Abbate
Department Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
Radicinin and cochliotoxin (1 and 2) two phytotoxic pyranpyran-4,5-diones were isolated together with their close metabolites 3-epi-radicinin, radicinol, and its 3-epimer (3−5), from the culture filtrates of Cochliobolus australiensis, a fungus proposed as mycoherbcide for biocontrol of buffelgrass, a very noxious and dangerous weed. The absolute configuration of cochliotoxin was determined by chiroptical Optical Rotatory Dispersion (ORD), Electronic Circular Dichroism (ECD), and Vibrational Circular Dichroism (VCD)) and computational methods. The same methods were used to confirm that of radicinin, radicinol and their 3-epimers, previously determined with chemical, spectroscopic and ECD methods.
