Chemical constituents of Thai propolis

Phytochemical investigation on the constituents of Thai propolis led the isolation of a new phenylallylflavanone, (7″S)-8-[1-(4'-hydroxy-3'-methoxyphenyl)prop-2-en-1-yl]-(2S)-pinocembrin (1) and (E)-cinnamyl-(E)-cinnamylidenate (2) from methanolic extract of Thai propolis. Their structures were determined on the basis of extensive NMR spectroscopic analysis. In addition to this, 19 compounds (3-21) belonging to flavonoids and phenolic esters...