作者:Benjamin G. Davis、Robert J. Nash、Alison A. Watson、Colin Smith、George W.J. Fleet
DOI:10.1016/s0040-4020(99)00138-6
日期:1999.4
The synthesis of [3.3.0] bicyclic tetrazoles derived from D-manno and D-rhamnofuranose starting from D-mannose, and of L-rhamnofuranose starting from L-rhamnose is described. The key step in the formation of all three examples of this novel class of sugar mimics is an intramolecular [1,3]-dipolar cycloaddition of azide and nitrile moieties.
Synthesis and biological evaluation of enantiomeric rhamnose analogues of the antitumour agent spicamycin—is the mode of action by modification of N-linked glycoproteins?
作者:Angeles Martı́n、Terry D Butters、George W.J Fleet
DOI:10.1016/s0957-4166(99)00240-2
日期:1999.6
The synthesis of both enantiomers of dodecyl rhamnospicamycin 2a and 2b, a rhamnose analogue of the naturally occurring combinatorial library spicamycin 1, are derived from L-rhamnose and methyl alpha-D-mannopyranoside, respectively. The L-(+)-enantiomer 2a containing an L-rhamnose fragment is shown to be highly cytotoxic towards human myeloma cells with an IC50=120 nM, whereas the D-(-)-enantiomer 2b, based on a D-mannose structure, shows no significant cytotoxicity. The analogue 16, in which the nucleotide base fragment has been replaced by a simple methoxy group, has no cytotoxicity. Initial studies towards clarifying the mechanism of anti-cancer action of spicamycin analogues are reported. (C) 1999 Elsevier Science Ltd. All rights reserved.