Gastradefurphenol,a minor 9,9'-neolignan with a new carbon skeleton substituted by two p-hydroxybenzyls from an aqueous extract of “tian ma”

Gastradefurphenol (1), a minor 9,9'-neolignan with a novel carbon skeleton substituted by two p-hydroxybenzyls was isolated from an aqueous extract of the Gastrodia elata rhizomes (tian ma). Its structure was determined by extensive spectroscopic data analysis. Solvent-dependent free rotational restriction of bonds and equilibrium of two molecular states are discussed by comparison of the NMR spectroscopic data of 1 in acetone-d₆ with those in CD₃OD. A biogenetic pathway of 1 is postulated to be associated with metabolic processes of L-tyrosine.