Eight glycosyl benzoxazole derivatives are synthesized by nucleophilic addition reactions of glycosyl isothiocyanate with o-aminophenol in tetrahydrofuran. The reaction conditions are optimized, and good yields (86%–94%) were obtained. The structures of all new products are confirmed by infrared, 1H nuclear magnetic resonance, and high-resolution mass spectrometry (electrospray ionization). In addition, the in vitro cholinesterase inhibitory activities of these new compounds are tested by Ellman’s method.

A series of glycosyl-substituted 1,3,4-oxadiazoles were synthesized by cyclization of glycosyl-acylthiosemicarbazides via a base-catalyzed reaction. The starting glycosyl-acylthiosemicarbazide derivatives were obtained by the reaction of glycosyl isothiocyanate with various hydrazides. The acetylcholinesterase (AChE) inhibitory activities of the products were tested by Ellman’s method. The most active compounds were subsequently evaluated for the 50% inhibitory concentration (IC50) values. N-(1,3,4,6-tetra-O-benzyl-2-deoxy-β-D-glucopyranosyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole-2-amine (6i) possesses the best AChE -inhibition activity with an IC50 of 1.61±0.34 μm.

No abstract

A new series of C2-glycosyl benzofuranylthiazole derivatives was synthesised by the further cyclization of glycosyl thiourea and 2-(bromoacetyl)-benzofuran via Hantzsch’s method. The corresponding 2-(bromoacetyl)-benzofuran derivatives were obtained by the reaction from various salicylaldehydes, and the glycosyl thiourea was prepared through a series of steps from D-Glucosamine. The acetylcholinesterase-inhibitory activities of the products were tested by Ellman’s method. The most active compounds were subsequently evaluated for the 50% inhibitory concentration values. N-(1,3,4,6-tetra-O-benzyl-2-deoxy-β-D-glucopyranosyl)-4-(5-methoxy-benzofuran-2-yl)-1,3-thiazole-2-amine possessed the best acetylcholinesterase-inhibition activity with a 50% inhibitory concentration of 2.03 ± 0.26 μM.

No abstract