title: Edible seaweed as future functional food: Identification of α-glucosidase inhibitors by combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR.
abstract: Crude chloroform, ethanol and acetone extracts of nineteen seaweed species were screened for their antioxidant and α-glucosidase inhibitory activity. Samples showing more than 60% α-glucosidase inhibitory activity, at a concentration of 1 mg/ml, were furthermore investigated using high-resolution α-glucosidase inhibition profiling combined with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HR-bioassay/HPLC-HRMS-SPE-NMR). The results showed Ascophyllum nodosum and Fucus vesicolosus to be rich in antioxidants, equaling a Trolox equivalent antioxidant capacity of 135 and 108 mM Troloxmg(-1) extract, respectively. HR-bioassay/HPLC-HRMS-SPE-NMR showed the α-glucosidase inhibitory activity of A. nodosum, F. vesoculosus, Laminaria digitata, Laminaria japonica and Undaria pinnatifida to be caused by phlorotannins as well as fatty acids - with oleic acid, linoleic acid and eicosapentaenoic acid being the most potent with IC50 values of 0.069, 0.075 and 0.10 mM, respectively, and showing a mixed-type inhibition mode.
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Bingrui
authors.initials: B
authors.lastname: Liu
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Kenneth T
authors.initials: KT
authors.lastname: Kongstad
authors.affiliation: Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wiese
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Jäger
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark. Electronic address: ds@sund.ku.dk.
authors.forename: Dan
authors.initials: D
authors.lastname: Staerk
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification*; D052160:Benzothiazoles / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D055951:Functional Food; D065089:Glycoside Hydrolase Inhibitors / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000737:chemistry; D012624:Seaweed / Q000737:chemistry* / Q000145:classification; D052616:Solid Phase Extraction / Q000379:methods; D013379:Substrate Specificity; D013451:Sulfonic Acids / Q000737:chemistry; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D000520:alpha-Glucosidases
keywords: Antioxidant capacity; Edible seaweed; Functional food; HPLC–HRMS–SPE–NMR; High-resolution inhibition profile; α-Glucosidase inhibition