Synthesis and cytotoxic activity of the N-acetylglucosamine-bearing triterpenoid saponins
摘要:
Fourteen ursolic acid and oleanolic acid saponins with N-acetyl-beta-D-glucosamine, and (1 -> 4)-linked and (1 6)-linked N-acetyl-beta-D-glucosamine oligosaccharide residues were synthesized in a convergent manner. The structures of all compounds were confirmed by (1)H NMR and (13)C NMR spectroscopy and by mass spectrometry, and their cytotoxic activities were assayed in three cancer cell lines. Only oleanolic acid-3-yl beta-D-GluNAc showed significant cytotoxicity against HL-60 and BGC-823. (C) 2010 Published by Elsevier Ltd.
Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzylethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH(3)OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.