New α‐Glucosidase Inhibitors and Antibacterial Compounds fromMyrtus communis L.

Three new acylphloroglucinols – myrtucommulone D (1), myrtucommulone E (2), and myrtucommulone C (3) – and a new usnic acid derivative usnone A (4) have been isolated from Myrtus communis L., along with the known acylphloroglucinol myrtucommulone B (5), one sterol 8 and six triterpenes 10–15, two flavonoids 6 and 9, and 2,5‐dihydroxy‐4‐methoxybenzophenone (cearoin; 7). The structures of compounds 1, 2, 4, and 5 were also unambiguously determined by single‐crystal X‐ray diffraction analysis. The compounds 1–3 and 5 were found to be more potent α‐glucosidase inhibitors than the clinically used standard acarbose. Compound 3 exhibited the highest activity among all the acylphloroglucinols, with an IC50 (inhibition concentration) = 35.4 ± 1.15 μM. Compounds 1, 2, 4, 7, and 11–15 also exhibited antibacterial activities.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)