Bioactive compounds from the leaves of Eugenia uniflora

From the MeOH extract of the leaves of Eugenia uniflora eight compounds were isolated, including one sterol, β-sitosterol (1); two triterpenes, betulinic acid (2) and centelloside C (8); three flavonoids, myricetrin (3), myricetin 3-O-(4’’-O-galloyl)-αL-rhamnopyranoside (4), and myricetin 3-O-β-D-glucopyranoside (5); and two megastigmanes, actinidioionoside (6), and (6S,9R)-roseoside (7). All the isolated compounds were obtained for the first time from this plant. The structures of isolated compounds were determined through a combination of spectroscopic and chemical analyses. All of the isolated compounds were evaluated for their antifungal, antibacterial, anti-leishmania, DPPH radical-scavenging and cytotoxic activities by means of MTT assay. Compounds 3 and 4 had antibacterial activity against S. aureus. Compounds 3‒5 showed potent IC50 in the DPPH radical scavenging activity. Compounds 4 and 5 exhibited moderate growth inhibitory activity toward A549.