De Novo Approach to 2-Deoxy-β-glycosides: Asymmetric Syntheses of Digoxose and Digitoxin<sup>1</sup>
作者:Maoquan Zhou、George A. O'Doherty
DOI:10.1021/jo062534+
日期:2007.3.1
straightforward route to trisaccharide natural products digoxose and digitoxin has been developed. Key to this approach is the iterative application of the palladium-catalyzed glycosylation reaction, reductive 1,3-transposition, diastereoselective dihydroxylation, and regioselective protection. The first total synthesis of natural product digoxose was accomplished in 19 total steps from achiral 2-acylfuran
A Direct Comparison of the Anticancer Activities of Digitoxin MeON-Neoglycosides and <i>O</i>-Glycosides
作者:Anand Krishnan V. Iyer、Maoquan Zhou、Neelam Azad、Hosam Elbaz、Leo Wang、Derek K. Rogalsky、Yon Rojanasakul、George A. O'Doherty、Joseph M. Langenhan
DOI:10.1021/ml1000933
日期:2010.10.14
Digitoxin is a cardiac glycoside currently being investigated for potential use in oncology; however, an investigation of anticancer activity as a function, of oligosaccharide chain length has not yet been performed. We generated mono-, di-, and tri-O-digitoxoside derivatives, of digitoxin and compared their activities to the corresponding MeON-neoglycosides. Both classes of cardenolide derivatives display comparable oligosaccharide chain length-dependent cytotoxicity toward human cancer cell lines. Further investigation revealed that both classes of compounds induce caspase-9-mediated apoptosis in non-small cell lung cancer cells (NCI-H460). Because O-glycosides and MeON-neoglycosides share a similar mode of action, the convenience of MeON-neoglycosylation could be exploited in future SAR work to rapidly survey large numbers of carbohydrates to prioritize selected O-glycoside candidates for traditional synthesis.