Glycosidic linkage comparisons

Fig. 6 Experimental ensemble corresponding to neomycin-B in the free state (a) in comparison with a theoretical ensemble corresponding to the antibiotic in complex with RNA (b) obtained from the MD simulations (starting from both X-Ray and NMR coordinates). Distribution of (solid) and iff (dotted) rotamers in both states are shown for the three glycosidic linkages (from top to bottom, I/II, III/II and IV/II)...

Fig. 10 a MD-tar ensembles of conformers for 2-4. The experimental ensemble corresponding to 1 in the free state (reft) is shown for comparison, b Structures representative of the main conformational families present in solution for neomycin-B derivatives 2 (left) and 3 (right) superimposed on the X-Ray structure of paromomycin in the complex with ribosomal RNA, according to X-Ray data. The maximum 4>/ U deviations (for each glycosidic linkage) is shown. Unit IV is omitted for simplicity... 

The amylolytic activity of A. oryzae o-atnylase is determined by comparison of the amount of glycosidic linkages broken in die standi to die amount released by a reference amylase under (he same experimental conditions. It is expressed in terms of micromoles of glycosidic linkages broken per minute. 

H-1 resonated at 8 4.69 as a d (J=7.9 Hz) and this large coupling constant indicated 1, 2-diaxial relationship with H-2 and proved the 3-glycosidic linkage. Furthermore, application of the Insight and Discover program (Biosym ) with bond-energy minimizations on the proposed structure supported this conclusion. Since a careful comparison of the... 

Table 4. Comparison of the NMR-Derived Raffinose Angles across the Glycosidic Linkages with Those Derived from the Crystal Structure. There are clear deviations for both linkages, the Glc-Fru being more pronounced.

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