AN NMR SPECTROSCOPIC AND CONFORMATIONAL STUDY OF 12 PSEUDO-DISACCHARIDES (D-GLUCOPYRANOSYL-5A-CARBA-D- AND -L-GLUCOPYRANOSES)

NMR spectroscopic data for 12 pseudo-disaccharides of the general stru cture: (alpha or beta)-D-glucopyranosyl-(1 --> x)-5a-carba-(D or L)-gl ucopyranose, representing analogues of laminaribiose (beta-D-Glcp, x = 3), cellobiose (beta-D-Glcp, x = 4), and maltose (alpha-D-Glcp, x = 4 ) are presented. The assigned NMR chemical shifts together with NOE di fference measurements in association with calculations applying the HS EA force field combined with Monte Carlo simulations have been used to assess the conformational preferences of the investigated compounds. The results are correlated with general structural features involved i n the interactions between monosaccharide units of oligosaccharides.