Modifying the glycosidic linkage in digitoxin analogs provides selective cytotoxins
摘要:
A chemoselective reaction between oxyamines and unprotected, unactivated reducing sugars was used to construct for the first time a panel of linkage-diversified neoglycosides. This panel of digitoxin analogs included potent and selective tumor cytotoxins; cytotoxicity was dependent on the structure of the glycosidic linkage. These results validate linkage diversification through neoglycosylation as a unique and simple strategy to powerfully complement existing methods for the optimization of glycoconjugates. (c) 2007 Elsevier Ltd. All rights reserved.
Synthesis and biological evaluation of RON-neoglycosides as tumor cytotoxins
作者:Joseph M. Langenhan、Matthew M. Endo、Jeffrey M. Engle、Liane L. Fukumoto、Derek R. Rogalsky、Lauren K. Slevin、Lindsay R. Fay、Ryan W. Lucker、James R. Rohlfing、Kyle R. Smith、Anja E. Tjaden、Halina M. Werner
DOI:10.1016/j.carres.2011.09.019
日期:2011.12
Cardenolides such as digitoxin have been shown to inhibit cancer cell growth, to reduce cancer metastasis, and to induce apoptosis in tumor cells. Among the most potent digitoxin-based cytotoxins identified to date are MeON-neoglycosides generated via oxyamine neoglycosylation. Here, we report our studies of oxyamine neoglycosylation aimed at facilitating the elucidation of linkage-diversified digitoxin neoglycoside structure-activity relationships. We identified conditions suitable for the convenient synthesis of digitoxin neoglycosides and found that sugar structure, rather than RON-glycosidic linkage, exerts the strongest influence on neoglycoside yield and stereochemistry. We synthesized a library of digitoxin neoglycosides and assessed their cytotoxicity against eight human cancer cell lines. Consistent with previous findings, our data show that the structure of RON-neoglycosidic linkages influences both the potency and selectivity of digitoxin neoglycosides. (C) 2011 Elsevier Ltd. All rights reserved.