C-(2-Deoxy-d-arabino-hex-1-enopyranosyl)-oxadiazoles: synthesis of possible isomers and their evaluation as glycogen phosphorylase inhibitors
摘要:
Synthetic methods were elaborated for D-glucals attached to oxadiazoles by a C-C bond. Introduction of the double bond was effected by either DBU induced elimination of PhCOOH from the O-perbenzoylated glucopyranosyl precursors or Zn/N-methylimidazole mediated reductive elimination from the 1-bromoglucopyranosyl starting compounds. Alternatively, heterocyclizations of 2-deoxy-D-arabino-hex-1-enopyranosyl cyanide were also carried out. Test compounds were obtained by Zemplen debenzoylation, however, none of them showed significant inhibition of rabbit muscle glycogen phosphorylase b. (C) 2015 Elsevier Ltd. All rights reserved.
Synthesis and structure–activity relationships of C-glycosylated oxadiazoles as inhibitors of glycogen phosphorylase
摘要:
A series of per-O-benzoylated 5-beta-D-glucopyranosyl-2-substituted-1,3,4-oxadiazoles was prepared by acylation of the corresponding 5-(beta-D-glucopyranosyl) tetrazole. As an alternative, oxidation of 2,6-anhydro-aldose benzoylhydrazones by iodobenzene I, I-diacetate afforded the same oxadiazoles. 1,3-Dipolar cycloaddition of nitrile oxides to per-O-benzoylated beta-D-glucopyranosyl cyanide gave the corresponding 5-beta-D-glucopyranosyl-3-substituted-1,2,4-oxadiazoles. The O-benzoyl protecting groups were removed by base-catalyzed transesterification. The 1,3,4-oxadiazoles were practically inefficient as inhibitors of rabbit muscle glycogen phosphorylase b while the 1,2,4-oxadiazoles displayed inhibitory activities in the micromolar range. The best inhibitors were the 5-beta-D-glucopyranosyl-3-(4-methylphenyl-and -2-naphthyl)- 1,2,4-oxadiazoles (K-i = 8.8 and 11.6 mu M, respectively). A detailed analysis of the structure-activity relationships is presented. (C) 2009 Elsevier Ltd. All rights reserved.
A series of per-O-benzoylated 5-beta-D-glucopyranosyl-2-substituted-1,3,4-oxadiazoles was prepared by acylation of the corresponding 5-(beta-D-glucopyranosyl) tetrazole. As an alternative, oxidation of 2,6-anhydro-aldose benzoylhydrazones by iodobenzene I, I-diacetate afforded the same oxadiazoles. 1,3-Dipolar cycloaddition of nitrile oxides to per-O-benzoylated beta-D-glucopyranosyl cyanide gave the corresponding 5-beta-D-glucopyranosyl-3-substituted-1,2,4-oxadiazoles. The O-benzoyl protecting groups were removed by base-catalyzed transesterification. The 1,3,4-oxadiazoles were practically inefficient as inhibitors of rabbit muscle glycogen phosphorylase b while the 1,2,4-oxadiazoles displayed inhibitory activities in the micromolar range. The best inhibitors were the 5-beta-D-glucopyranosyl-3-(4-methylphenyl-and -2-naphthyl)- 1,2,4-oxadiazoles (K-i = 8.8 and 11.6 mu M, respectively). A detailed analysis of the structure-activity relationships is presented. (C) 2009 Elsevier Ltd. All rights reserved.
C-(2-Deoxy-d-arabino-hex-1-enopyranosyl)-oxadiazoles: synthesis of possible isomers and their evaluation as glycogen phosphorylase inhibitors
Synthetic methods were elaborated for D-glucals attached to oxadiazoles by a C-C bond. Introduction of the double bond was effected by either DBU induced elimination of PhCOOH from the O-perbenzoylated glucopyranosyl precursors or Zn/N-methylimidazole mediated reductive elimination from the 1-bromoglucopyranosyl starting compounds. Alternatively, heterocyclizations of 2-deoxy-D-arabino-hex-1-enopyranosyl cyanide were also carried out. Test compounds were obtained by Zemplen debenzoylation, however, none of them showed significant inhibition of rabbit muscle glycogen phosphorylase b. (C) 2015 Elsevier Ltd. All rights reserved.