Synthesis and cytostatic evaluation of 4-N-alkanoyl and 4-N-alkyl gemcitabine analogues
The coupling of gemcitabine with functionalized carboxylic acids (C9-C13) or reactions of 4-N-tosylgemcitabine with the corresponding alkyl amines afforded 4-N-alkanoyl and 4-N-alkyl gemcitabine derivatives. The analogues with a terminal hydroxyl group on the alkyl chain were efficiently fluorinated under conditions that are compatible with protocols for 18F labeling. The 4-N-alkanoylgemcitabines showed potent cytostatic activities in the low nanomolar range against a panel of tumor cell lines, whereas cytotoxicity of the 4-N-alkylgemcitabines were in the low micromolar range. The cytotoxicity for the 4-N-alkanoylgemcitabine analogues was reduced approximately by 2 orders of magnitude in the 2′-deoxycytidine kinase (dCK)-deficient CEM/dCK - cell line, whereas cytotoxicity of the 4-N-alkylgemcitabines was only 2-5 times lower. None of the compounds acted as efficient substrates for cytosolic dCK; therefore, the 4-N-alkanoyl analogues need to be converted first to gemcitabine to display a significant cytostatic potential, whereas 4-N-alkyl derivatives attain modest activity without measurable conversion to gemcitabine.
Pulido, Jesse,Sobczak, Adam J.,Balzarini, Jan,Wnuk, Stanislaw F.
supporting information
p. 191 - 203
(2014/02/14)
INTERPRETING SUBSTITUENT EFFECTS ON THE CRYSTAL PACKING OF LONG-CHAIN DIACYL PEROXXIDES. THE CRYSTAL STRUCTURES OF DI(11-BROMOUNDECANOYL) PEROXIDE AND DI(UNDECANOYL) PEROXIDE
Although crystals of di(11-bromoundecanoyl) peroxide and di(undecanoyl) peroxide have different space groups (P43212 and C2221), the molecules pack in almost identical layers.They differ only in the nature of stacking across interfaces involving the terminal groups.Because the 90 deg twist about the O-O bond locks neighboring molecules together within the layer, each peroxide shows a single solid phase from 5K to the melting point.Analysis of the stacking pattern in terms of the six possible orientational relationships suggests special stability for an L-shaped motif of C-Br...Br-C.Other substituents create different stackings of the same layer structure to give three crystal classes and five space groups among 14 compounds.Unsymmetrical peroxides are useful both for forcing a variety of substituted chains (particularly odd-even homologues) to pack with identical layer structures, and for controlling the stacking pattern.Because structural differences are localized in the vicinity of the substituents, this series of "substitutional polytypes" will allow systematic investigation of substituent effects on the physical and chemical properties of solids.
McBride, J. Michael,Bertman, Steven B.,Cioffi, Donna Z.,Segmuller, Brigitte E.,Weber, Bruce A.