Structure determination of bioactive galloyl derivatives by NMR spectroscopy.
The investigation of the chemical constituents of Symplocos racemosa Roxb led to the isolation of two new glycosides, symcomoside A (1) and symcomoside B (2), together with one known glycoside, tortoside C (3), which is reported for the first time from this plant. The structures of the new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy, from chemical evidence and by comparison with published data for closely related compounds. Symcomoside B (2) showed potent inhibitory activity against alpha-glucosidase in a concentration-dependent fashion with an IC50 value of 0.733 +/- 0.033 mM whereas symcomoside A (1) showed very weak inhibitory activity against alpha-glucosidase (9.90% in 0.70 mM).
Ahmad
Viqar Uddin
VU
H.E.J. Research Institute of Chemistry, International Center for Chemical Sciences, University of Karachi, Karachi-75270, Pakistan. vuahmad@cyber.net.pk
Zubair
Muhammad
M
Athar Abbasi
Muhammad
M
Abid Rashid
Muhammad
M
Rasool
Nasir
N
Nahar Khan
Shamsun
S
Iqbal Choudhary
M
M
Kousar
Farzana
F
D002247:Carbon Isotopes; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000302:isolation & purification; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards*; D019684:Magnoliopsida / Q000737:chemistry*; D008968:Molecular Conformation; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011522:Protons; D012015:Reference Standards
D002247:Carbon Isotopes; D005960:Glucosides; D006027:Glycosides; D010936:Plant Extracts; D011522:Protons; C502054:symcomoside A; C502055:symcomoside B; D005707:Gallic Acid