D-Mannose and deriv

The inhibition of precipitin formation by 1-thio-D-mannose and derivatives is shown in the results recorded in Plates C, D, E, and F of Fig. 13. The sulfur derivatives, p-nitrophenyl 1-thio-D-mannopyranoside (well Ii) and ethyl 1-thio-D-mannopyranoside (well I3), caused a marked decrease in the amount of precipitin formation, in comparison to that obtained with the native antibodies (Well A,). However, mannose did not decrease the amount of precipitin formation (well I2). This compound did not bind to the combining site of the antibody. Apparently, the thio group at position 1 of the mannose is required for the binding to occur. 

The incorporation and metabolism of 2-deoxy-2-fluoro-D-[ H]glucose and -D-[ H]mannose in yeast and chick-embryo cells has been studied. 2-Deoxy-2-fluoro-D-glucose, 2-deoxy-2-fluoro-D-mannose, and their GDP and UDP derivatives were found to interfere with protein (involving that of... 

Gurin164 has tabulated data from an examination of gonadotropic substances derived from several sources. The luteinizing hormone and the F. S. H. from the pituitary are stated to contain D-mannose and... 

The molecular weight (94,000) was smaller than that of other microbial P-mannosidases such as Aspergillus o/jCTe( 120,000-135,000) and Tremella fuciformis (160,000-200,000). The final product from the oligosaccharides with the enzyme was mainly D-mannose and the enzymatic activity was not inhibited by D-mannose or mannose-derivatives such as D-mannosamine, D-mannonic acid and D-mannitol. 

Yoshida and coworkers387 have compared the retention times of 41 furanosides and pyranosides of D-glucose, D-galactose, D-mannose, and D-glucuronic acid as their O-trimethylsilyl, O-acetyl, and O-tri-fluoroacetyl derivatives. 

As a consequence, 4,6-O-isopropylidene derivatives are obtained from D-aldohex-oses this has now been demonstrated not only for D-allose, D-galactose, D-glucose, D-mannose, and D-talose, but also for D-gulose (J. Gelas and D. Horton, unpublished results see also, Ref. 15) it may reasonably be assumed that it will also be found for D-altrose and D-idose. 

The major mechanistic and structural aspect of the acetalation process is its orientation toward derivatives obtained either under thermodynamically controlled conditions or under kinetically controlled conditions. We will not discuss here all structural factors concerning the relative stabilities of acyclic and cyclic acetals of polyols and monosaccharides, because such a discussion has been extensively reviewed and adequately commented on [8,10,12 -14]. However, it is important to focus here on the main consequences of these relative stabilities in relation to the various experimental conditions to orientate the choice of specific conditions, particularly for the most important monosaccharides (D-glucose, D-mannose, and D-galactose). 

Monomethyl-D-mannoses and Some of Their Characteristic Derivatives... 

Table III records appropriate data and references relating to the trimethyl-D-mannoses and their more important derivatives.

M. Cerny, J. Stanek, Jr., and J. Pacak, Syntheses with anhydro sugars. 7. Preparation of 4-deoxy-D-rifto-hexose (4-deoxy-D-allose), 4-deoxy-D-(yvo-hexose (4-deoxy-D-mannose) and of their 1,6-anhydro derivatives, Collect. Czech. Chem. Commun., 34 (1969) 1750-1765. 

To obtain this type of D-glucosamine donor in a stereocontrolled manner, another glycal derivative, namely 3-0-benzyl-2-deoxy-5,6-O-isopropyli-dene-D-araW o-l,4-anhydro-hex-l-enitol (151), was chosen as starting material because it is easily prepared from D-mannose and because the j8-face of the double bond is very hindered.79 As anticipated, azido-phenylselenyla-tion of 151 afforded an a//3 mixture of phenyl 2-azido-2-deoxy-l-seleno-D-glucofuranosides 152 in high yield. In order to obtain the glucosamine equivalent in pyranose form, compound 152 was treated under acidic conditions in the presence of mercury acetate to effect simultaneous cleavage of... 

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