The Structure of Hildecarpin, an Insect Antifeedant 6a-Hydroxypterocarpan from the Roots of Tephrosia Hildebrandtii Vatke

Abstract

The structure of hildecarpin, an insect antifeedant 6a-hydroxypterocarpan isolated from the roots of Tephrosia hildebrandtii has been confirmed by a combination of degradation reactions, NMR and mass spectra. Hildecarpin has been dehydrated to the corresponding pterocarpene 3-hydroxy-2-methoxy-8,9-methylenedioxypterocarpene. Hydrogenation and hydrogenolysis of the pterocarpene has afforded the isoflavan 2′, 7-dihydroxy-6-methoxy-4′,5′-methylenedioxyisoflavan, acetylation of which has led to 2′,7-diacetoxy-6-methoxy-4′,5′-methylenedioxyisoflavan. The NMR and mass spectra of the degradation products confirm the structure previously assigned to hildecarpin.

Résumé

La structure de hildecarpin, un insecte antiparasitaire 6a-hydroxypterocarpan isolé des racines de Tephrosia hildebrandtii a été confirmer par une combinaison de réactions de dégradations, NMR et le masse spectre. Hildecarpin a été déshydrater au correspondant pterocarpene 3-hydroxy-2-methoxy-8,9-methylenedioxypterocarpene. L’hydrogénation et l’hydrogenolysis de le pterocarpene a fourni l’isoflavan 2′,7-dihydroxy-6-methoxy-4′,5′-methylenedioxyisoflavan, l’acetylation de laquelle a conduit à 2′,7-dia-cetoxy-6-methoxy-4′,5′-methylenedioxyisoflavan. Le NMR et le masse spectra des produits de dégradation confirme la structure qui était preá lablement assigner à hildecarpin.