Abstract

Propolis is a natural product produced by bees, and it is a mixture of resins and other bee excretions. The chemical composition of each type of propolis and its associated bioactivities also depend on the geographical regions, its food and the bee species. In Vietnam, propolis has been used in traditional medicine as the remedy to improve health and prevent diseases. From the ethanolic extract of the stingless bee propolis Trigona minor (Meliponini, Apidae), four lignan compounds were isolated. Their chemical structures were determined as (+)-isolariciresinol (1), 5-methoxy-(+)- isolariciresinol (2), (+)-lyoniresinol (3), and 6-(4- hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3.3.0] octan-2-one (4) by spectroscopic methods as well as comparing with data in the literature. Among them, compound 4 was the first isolated from natural sources, while others were isolated for the first time from this stingless bee propolis.