Scopoletin from the flower buds of Magnolia fargesii inhibits protein glycation, aldose reductase, and cataractogenesis Ex Vivo

Abstract

Five compounds previously known structures, scopoletin (1), northalifoline (2), stigmast-4-en-3-one (3), tiliroside (4), and oplopanone (5) were obtained from the flower buds of Magnolia fargesii using chromatographic separation methods. The structures of 1-5 were identified by the interpretation of their spectroscopic data including 1D- and 2D-NMR as well as by comparison with reported values. Three compounds 1-3 were found from M. fargesii for the first time in this study. All the isolates (1-5) were subjected to in vitro bioassays to evaluate the inhibitory activity on advanced glycation end products formation and rat lens aldose reductase (RLAR). Compound 1 showed a remarkable inhibitory activity on advanced glycation end products formation with IC50 value of 2.93 μM (aminoguanidine: 961 μM), and showed a significant RLAR inhibitory activity with IC50 value of 22.5 μM (3.3-tetramethyleneglutaric acid: 28.7 μM). Compound 4 exhibited potent inhibitory activity against RLAR (IC50 = 14.9 μM). In the further experiment ex vivo, cataractogenesis of rat lenses induced with xylose was significantly inhibited by compound 1 treatment. © 2010 The Pharmaceutical Society of Korea and Springer Netherlands.