Filiferol, a chalconoid analogue from Washingtonia filifera possibly involved in the defence against the Red Palm Weevil Rhynchophorus ferrugineus Olivier

Abstract A chalconoid analogue, 1,3,5-benzentriol 2-[(2S,3R)-3-(3,4-dihydroxylphenyl)-2,3-dihydroxylpropyl], named filiferol ( 1 ), has been isolated and purified for the first time from the leaf basal tissues of the palm species Washingtonia filifera . The chemical structure of the isolated compound has been elucidated unambiguously by spectroscopic and chemical methods. Filiferol has been based on a flavonol structure with the reduction of the common flavonoid keto group to give an unprecedented methylene carbon on the three carbon chain. An analogous compound with S stereochemistry at C3 has been obtained as synthetic intermediate for developing an enantioselective synthesis of (2R,3S)-(+)-catechin. Even though 1 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. 1 has been isolated from leaf tissues of W. filifera , a species resistant to this pest, but this molecule seems instead undetectable in tissues of other palm species susceptible to the parasite. The presence of 1 could therefore account for W. filifera natural resistance to the attacks of the Red Palm Weevil ( R. ferrugineus ).