title: Alpha-amylase inhibitory activity and sterol composition of the marine algae, Sargassum glaucescens.
abstract: BACKGROUND
  Sargassum species (phaeophyceae) are economically important brown algae in southern parts of Iran. Sargassum is mainly harvested as a row material in alginate production industries and is a source of plant foods or plant bio-stimulants even a component of animal foods.
  
  
  OBJECTIVE
  In this study, Sargassum glaucescens, collected from the seashore of Chabahar, was employed for phytochemical and biological evaluations.
  
  
  METHODS
  For that purpose, the dried algae was extracted by methanol and subjected to different chromatographic separation methods.
  
  
  RESULTS
  Six sterols, fucosterol (1), 24(S)-hydroxy-24-vinylcholesterol (2), 24(R)-hydroxy-24-vinylcholesterol (3), stigmasterol (4), β-sitosterol (5) and cholesterol (6) were identified by spectroscopic methods including (1)H-NMR, (13)C-NMR and mass spectroscopy. In vitro alpha-amylase inhibitory test was performed on the methanolic extract and the results revealed a potent inhibition (IC50 = 8.9 ± 2.4 mg/mL) of the enzyme compared to acarbose as a positive control.
  
  
  CONCLUSIONS
  Various biological activities and distribution of sterols in Sargassum genus have been critically reviewed here. The results concluded that these algae are a good candidate for further anti-diabetic investigations in animals and human.
authors.affiliation: Department of Marine Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Payghami
authors.affiliation: Department of Marine Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Shahla
authors.initials: S
authors.lastname: Jamili
authors.affiliation: Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Abdolhossein
authors.initials: A
authors.lastname: Rustaiyan
authors.affiliation: Medicinal Plants Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Soodabeh
authors.initials: S
authors.lastname: Saeidnia
authors.affiliation: Medicinal Plants Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Nikan
authors.affiliation: Medicinal Plants Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Gohari
keywords: Alpha-amylase inhibitor; Brown algae; Sargassum glaucescens; Sterol