title: Protein tyrosine phosphatase 1B and α-glucosidase inhibitory Phlorotannins from edible brown algae, Ecklonia stolonifera and Eisenia bicyclis.
abstract: The present work investigates protein tyrosine phosphatase 1B (PTP1B) and the α-glucosidase inhibitory activities of two edible brown algae, Ecklonia stolonifera and Eisenia bicyclis, as well as in their isolated phlorotannins. Since the individual extracts and fractions showed significant inhibitory activities, column chromatography was performed to isolate six phlorotannins, phloroglucinol (1), dioxinodehydroeckol (2), eckol (3), phlorofurofucoeckol-A (4), dieckol (5), and 7-phloroeckol (6). Phlorotannins 3-6 were potent and noncompetitive PTP1B inhibitors with IC(50) values ranging from 0.56 to 2.64 µM; 4-6 exhibited the most potent α-glucosidase inhibition with IC(50) values ranging from 1.37 to 6.13 µM. Interestingly, 4 and 6 were noncompetitive, while 5 exhibited competitive inhibition in an α-glucosidase assay. E. stolonifera and E. bicyclis as well as their isolated phlorotannins therefore possessed marked PTP1B and α-glucosidase inhibitory activities; this could lead to opportunities in the development of therapeutic agents to control the postprandial blood glucose level and thereby prevent diabetic complications.
authors.affiliation: Department of Food Science and Nutrition, Pukyong National University, Busan, Republic of Korea.
authors.forename: Hye Eun
authors.initials: HE
authors.lastname: Moon
authors.forename: Nurul
authors.initials: N
authors.lastname: Islam
authors.forename: Bo Ra
authors.initials: BR
authors.lastname: Ahn
authors.forename: Sabiha Sultana
authors.initials: SS
authors.lastname: Chowdhury
authors.forename: Hee Sook
authors.initials: HS
authors.lastname: Sohn
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Jung
authors.forename: Jae Sue
authors.initials: JS
authors.lastname: Choi
mesh_terms: D001572:Benzofurans / Q000737:chemistry / Q000494:pharmacology; D001786:Blood Glucose / Q000032:analysis; D045424:Complex Mixtures / Q000737:chemistry / Q000494:pharmacology; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000201:enzymology* / Q000503:physiopathology; D004147:Dioxins / Q000737:chemistry / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy / Q000201:enzymology* / Q000503:physiopathology; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D000459:Phaeophyceae / Q000737:chemistry*; D010696:Phloroglucinol / Q000737:chemistry / Q000494:pharmacology; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012996:Solutions; D013053:Spectrophotometry; D013634:Tannins / Q000737:chemistry / Q000494:pharmacology*; D015003:Yeasts; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: C558314:7-phloroeckol; D001572:Benzofurans; D001786:Blood Glucose; D045424:Complex Mixtures; D004147:Dioxins; D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D012996:Solutions; D013634:Tannins; C503840:dieckol; C550453:dioxinodehydroeckol; C060311:eckol; D010696:Phloroglucinol; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D000520:alpha-Glucosidases