Regiolone and Isosclerone, Two Enantiomeric Phytotoxic Naphthalenone Pentaketides: Computational Assignment of Absolute Configuration and Its Relationship with Phytotoxic Activity

• Published in: European Journal of Organic Chemistry 2011-10, Vol.2011 (28), p.5564-5570
• Main Authors: Evidente, Antonio, Superchi, Stefano, Cimmino, Alessio, Mazzeo, Giuseppe, Mugnai, Laura, Rubiales, Diego, Andolfi, Anna, Villegas-Fernández, Angel M.
• Format: Article
• Language: English
• Subjects: Ab initio calculations; Biological activity; Chemistry; Circular dichroism; Condensed benzenic and aromatic compounds; Configuration determination; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Organic chemistry; Phytotoxicity; Preparations and properties
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201100941

The absolute configurations of regiolone and isosclerone, two enantiomeric bioactive naphthalenone pentaketides produced by fungi and plants, have been unambiguously assigned by ab initio computational prediction of their theoretical optical rotatory powers and electronic circular dichroism spectra. Isosclerone is produced by the plant pathogen Botrytis cinerea, whereas regiolone is produced by B. fabae. The phytotoxic activities of the two compounds were tested for comparison on faba bean (host of both pathogens) and vine plants (host of only B. cinerea); the (R) configuration at C‐4 was found to be a fundamental structural feature for bioactivity. The absolute configurations of regiolone [(–)‐1] and isosclerone [(+)‐1] have been unambiguously assigned by ab initio computational prediction of their theoretical optical rotatory powers and electronic circular dichroism spectra. The phytotoxicities of the two compounds were tested for comparison on the faba bean and vine plants; the (R) configuration at C‐4 was found to be a fundamental structural feature forbioactivity.