Synthesis and characterisation of N -glycosyl amines from the reaction between 4,6-O -benzylidene-D-glucopyranose and substituted aromatic amines and also between 2-(o -aminophenyl)benzimidazole and pentoses or hexoses T. Mohan Das, a Chebrolu P. Rao, a, * Erkki Kolehmainen b a Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India b Department of Chemistry, Uniersity of Jyaskyla, Jyaskyla Fin 40351, Finland Abstract Twelve N -glycosyl amines were synthesised using 4,6-O -benzylidene-D-glucopyranose and different substituted aromatic amines, including some diamines that resulted in bis-glycosyl amines. Another set of six N -glycosyl amines was synthesised using different hexoses and pentoses and 2-(o -aminophenyl)benzimidazole. All compounds were isolated as solid products and purified, their elemental compositions were established, and these were characterised by NMR ( 1 H and 13 C), UV – Vis, and FTIR spectroscopy, by FAB mass spectrometry (molecular-ion peaks gave molecular weights), and by their optical rotations. While the protected saccharide, 4,6-O -benzylidene-D-glucopyran- ose, exists as a mixture of  and  anomers in solution, the corresponding N -glycosyl amines were of only the  anomeric form as determined by NMR and FTIR spectroscopy. On the other hand, N -glycosyl amines synthesised from 2-(o -aminophenyl)benzimidazole prefer the  anomeric form, and in two cases a mixture of both the  and the  anomers were observed. The trends observed in the chemical shifts were compared among different products. Keywords: N-Glycosyl amines;  and  anomers; Optical rotation; 4,6-O-Benzylidene-D-glucopyranose; 4,6-O-Butylidene-D- glucopyranose; 2-(o -Aminophenyl)benzimidazole; Hydrogen-bonding interaction 1. Introduction The finding of insulin-like activity associ- ated with various alkyl and aryl glycosyl amines 1 and their generally wide range of biological activities 2 prompted our study of N -glycosyl amines. Glycosyl amines 3 are im- portant because these occur as junctures in glycoproteins. 4 The chemical and structural nature of the derivatives formed from the reaction of a monosaccharide and different nitrogen bases depends upon the reaction con- ditions and the base used. Thus glycosyl amines exist either in cyclic or acyclic form. 5 Benzimidazole-based non-glycosyl amine derivatives exhibit a range of biological activi- ties. 6 N -Glycosyl amines have better advan- tage in binding to metal ions over their sac-