Phytochemical investigations of the EtOH extract of Populus tremuloides leaf buds led to the isolation of 19 phenolic compounds. Among them, (1S,2S)-1-[4-O-E-coumaroyl-β-d-glucopyranosyloxy]cyclohexanediol was reported for the first time, and its structure was determined by spectroscopic (NMR and MS) and chemical methods. Seventeen of the isolated compounds were tested for their cytotoxicity against lung carcinoma (A549) and colorectal adenocarcinoma (DLD-1) human cell lines. Antibacterial activity was also evaluated against Escherichia coli and Staphylococcus aureus .