Filiferol, a chalconoid analog from Washingtonia filifera possibly involved in the defense against the red palm weevil Rhynchophorus ferrugineus Olivier

A chalconoid analog, 1,3,5-benzentriol 2-[(2S,3R)-3-(3,4-dihydroxylphenyl)-2,3-dihydroxylpropyl], named filiferol (I), has been isolated and purified for the first time from the leaf basal tissues of the palm species Washingtonia filifera. The chem. structure of I has been elucidated unambiguously by spectroscopic and chem. methods. I has been based on a flavonol structure with the redn. of the common flavonoid keto group to give an unprecedented methylene carbon on the three carbon chain. An analogous compd. with S stereochem. at C3 has been obtained as synthetic intermediate for developing an enantioselective synthesis of (2R,3S)-(+)-catechin. Even though I proved to be deprived of antifungal properties, it displays a very effective larvicidal activity against red palm weevil, Rhynchophorus ferrugineus, an important pest affecting cultivated and ornamental palms. I has been isolated from leaf tissues of W. filifera, a species resistant to this pest, but this mol. seems instead undetectable in tissues of other palm species susceptible to the parasite. The presence of I could, therefore, account for W. filifera natural resistance to the attacks of the red palm weevil. [on SciFinder(R)]