title: Inhibitors of α-glucosidase and α-amylase from Cyperus rotundus.
abstract: BACKGROUND
  A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion.
  
  
  OBJECTIVE
  Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase.
  
  
  METHODS
  Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays.
  
  
  RESULTS
  A new (2RS,3SR)-3,4',5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity.
  
  
  CONCLUSIONS
  The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents.
  
  
  CONCLUSIONS
  The isolated compounds may contribute to the antidiabetic property of C. rotundus.
authors.affiliation: Institute of Marine Biochemistry, Vietnam Academy of Science and Technology , 18-Hoang Quoc Viet, Cau Giay, Hanoi , Vietnam and.
authors.forename: Hong Hanh Thi
authors.initials: HH
authors.lastname: Tran
authors.forename: Minh Chau
authors.initials: MC
authors.lastname: Nguyen
authors.forename: Hoang Tram
authors.initials: HT
authors.lastname: Le
authors.forename: Thi Luyen
authors.initials: TL
authors.lastname: Nguyen
authors.forename: Thanh Binh
authors.initials: TB
authors.lastname: Pham
authors.forename: Van Minh
authors.initials: VM
authors.lastname: Chau
authors.forename: Hoai Nam
authors.initials: HN
authors.lastname: Nguyen
authors.forename: Tien Dat
authors.initials: TD
authors.lastname: Nguyen
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D029786:Cyperus / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D027343:Rhizome; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
chemical_list: D001713:Biphenyl Compounds; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl; D000516:alpha-Amylases