α-Amylase and α-glucosidase inhibitory activities of the herbs of Artemisia dracunculus L. and its active constituents

A new phenylpropanoid named 4-(1′,1′,2′,2′-tetramethylpropyl)-1,2-benzenediol ( 1 ) with a known phenylpropanoid: 3-( p -methoxyphenyl)-1,2-propanediol ( 2 ), a coumarin: herniarin ( 3 ), and a flavonol glycoside: rutin ( 4 ) were isolated from the aerial parts of Artemisia dracunculus L. Their structures were elucidated by detailed analyses of 1D and 2D nuclear magnetic resonance, IR, ESI–MS and HR–ESI–MS data. Methanol extract of aerial parts of the plant, different polarity fractions of methanol extract and the isolated compounds from these fractions were evaluated for their alpha amylase and alpha glucosidase inhibitory effects. Phenylpropanoids containing fraction had a significantly higher α-glucosidase inhibitory activity (90.4%) when compared with the standart compound acarbose (26.0%) at 1 mg/mL. However none of the tested extracts or compounds were found to be active on α-amylase inhibition.