Characterization of phenolic compounds from Rhododendron alutaceum.

A new phenolic glycoside, 3'-keto rhododendrin and a new sesquilignan, alutaceuol, together with twelve known phenolic compounds, were isolated from the leaves of Rhododendron alutaceum. Their structures were elucidated by extensive spectroscopic data analysis and comparison with literature values. In addition, the detailed analysis of 2D NMR data led us to conclude that the chemical shifts of dihydrobuddlenol B need to be revised.