NMR assignments of unusual flavonoids from the kino of Eucalyptus citriodora

Abstract Two unusual flavonoids, 3,5,4′,5″‐tetrahydroxy‐7‐methoxy‐6‐[1‐( p ‐hydroxy‐phenyl)ethyl]flavanone (1) and 3,5,7,4′,5″‐pentahydroxy‐6‐[1‐( p ‐hydroxy‐phenyl)ethyl] flavanone (2), were isolated from the kino of Eucalyptus citriodora . Structural elucidation of the new compounds were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift‐correlated NMR pulse sequences ( 1 H, 1 H‐COSY, HMQC, HMBC). Copyright © 2007 John Wiley & Sons, Ltd.