| Nowadays, a large number of compounds derived from plants are used in modern medicine and a majority of them are inspired by traditional applications. About 60% of anticancer drugs and 75% of compounds for infectious diseases are either natural products or their derivatives. However, it is estimated that only bioactive molecules of 5 to 15% of more than 250'000 plants species on earth have been investigated. Particularly, few scientific studies have been conducted on bioactive compounds from the medicinal plants of the boreal forest, wide-spread in Quebec and Canada. In recent years, LASEVE laboratory has evaluated the potential pharmacology of many plants and it was apparent that the buds of Populus tremuloides would represent an interesting subject of study in chemistry and pharmacology. In North America, leaf-buds of P. tremuloides were used in traditional medicine to treat numerous diseases. The aim of this research project was to isolate and characterize the polyphenolic constituents in buds of P. tremuloides and to evaluate the biological activities of the purified fractions and pure compounds. Phytochemical investigations of the EtOH extract of P. tremuloides leaf-buds led to the isolation of 24 phenolic compounds. Among them, one compound is a new molecule and was not reported in literature before two compounds were not reported before for Salicaceae family two compounds were not reported before for Populus genus and ten compounds were identified for the first time in P. tremuloides . Three of the identified compounds have exhibited a moderate to strong cytotoxicity (5-20 muM) towards some of cellular tested lines (WS1, DLD-1, A-549). Anti-inflammatory activity of five phenolic compounds having a glycerol section has been evaluated using LPS-stimulated RAW 264.7 macrophages. Only one of the tested compounds significantly inhibited nitric oxide production (IC50: 6.5 +/- 0.4 muM), without cytotoxicity. Finally, none of the phenolic compounds isolated in the present work have exhibited a significant activity against Staphylococcus aureus and Escherichia coli. |
