Abstract: Three new acylphloroglucinols, myrtucommulone-D (Compound 1), myrtucommulone-E (Compound 2), myrtucommulone-C (Compound 3), and a known acyphloroglucinol myrtucommulone B (Compound 4) were isolated from a methanolic extract of Myrtus communis L. The structures of compounds 1, 2 and 4 were also unambiguously determined by single X-ray diffraction analysis. The compounds 1-4 were found to be more potent ?-glucosidase inhibitors than the clinically used standards, acarbose and deoxynojirimycin. The compound 3 exhibited the highest activity among all the acylphloroglucinols, with an IC50=35.4±1.15 ?M. The compounds 1 and 2 also exhibited strong antibacterial activities.