title: A New Sucrase Enzyme Inhibitor from Azadirachta indica.
abstract: BACKGROUND
  Sucrase enzyme inhibitor considered as an oral anti-diabetic therapy that delays the absorption of eaten carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycemia.
  
  
  METHODS
  Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica growing in KSA, followed by in-vitro assay of sucrase enzyme inhibition activity.
  
  
  RESULTS
  This investigation led to the isolation of a new remarkable sucrase enzyme inhibitor; 4'-methyl Quercetin-7-O-β-D-glucuronopyranoside (1) alongside with four known compounds; 2,3-hexahydroxydiphenoyl-(α/β)-D-(4)C1-glucopyranose (2), Avicularin (3), Castalagin (4) and Quercetin-3-O-glucoside (5). The structure of the new compound (1) was elucidated on the basis of its spectral data, including ESI-MS, UV, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, HSQC, NOESY and HMBC.
  
  
  CONCLUSIONS
  Under the assay conditions, hydroalcoholic extract of A. indica and compounds 1-5 exhibited significant sucrase enzyme inhibitory activity.
  
  
  CONCLUSIONS
  Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica, led to the Isolation of a new flavonoid glycoside named 4'-methyl Quercetin-7-O-β-D-glucuronopyranoside, alongside to other 4 known polyphenols. The hydroalcoholic extract as well as the isolated compounds exhibited significant sucrase enzyme inhibitory activity. Abbreviations used: ESI-MS; electrospray ionization-mass spectrometry, UV; ultraviolet, NMR; nuclear magnetic resonance, 1H-1H COSY; 1H-1H correlation spectroscopy, NOESY; nuclear overhauser effect spectroscopy, and HSQC; heteronuclear multiple bond correlation. A. indica; Azadirachta indica.
authors: Department of Pharmacognosy, Faculty of Pharmacy, Umm Al-Qura University, Makkah 21955, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Helwan University, Cairo 11795, Egypt.
authors: Mohamed I S
authors: MI
authors: Abdelhady
authors: Department of Pharmacognosy, Faculty of Pharmacy, Umm Al-Qura University, Makkah 21955, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt.
authors: Usama
authors: U
authors: Shaheen
authors: Department of Pharmacognosy, Faculty of Pharmacy, Umm Al-Qura University, Makkah 21955, Saudi Arabia.
authors: Ammar
authors: A
authors: Bader
authors: Department of Biochemistry, Faculty of Pharmacy, Helwan University, Cairo 11795, Egypt; Division of Functional Genome Analysis, German Cancer Research Center, Heidelberg, Germany.
authors: Mahmoud A
authors: MA
authors: Youns
keywords: Azadirachta indica; polyphenols; sucrase inhibitor