A New Approach to 3′-Amino-3′-deoxynucleosides. Synthesis of 9-(3-Amino-3-deoxy-α-L-ribofuranosyl)adenine

1971 ◽  
Vol 49 (4) ◽  
pp. 568-573 ◽  
Author(s):  
Hans H. Baer ◽  
Monika Bayer
Keyword(s):  
Catalytic Hydrogenation ◽  
Title Compound ◽  
Condensation Product ◽  
Periodate Oxidation ◽  
Borohydride Reduction ◽  
New Approach

Methyl 2,3,4-tri-O-acetyl-6-deoxy-6-nitro-α-D-glucopyranoside (1) was acetolyzed to give 1,2,3,4-tetra-O-acetyl-6-deoxy-6-nitro-α-D-glucopyranose (2). Compound 2 (or alternatively, 6-deoxy-1,2-O-isopropylidene-6-nitro-α-D-glucofuranose 4) was converted into 2,3,4-tri-O-acetyl-6-deoxy-6-nitro-α- D-glucopyranosyl bromide (3) which was condensed with chloromercuri 6-benzamidopurine. De-O-acetylation of the condensation product 5 afforded 6-benzamido-9-(6-deoxy-6-nitro-β-D-glucopyranosyl)purine (6) which could be hydrogenated to the corresponding 6′-amino nucleoside 7. Periodate oxidation of 6 followed by internal Henry cyclization and borohydride reduction gave 6-benzamido-9-(3-deoxy-3-nitro-α-L-ribofuranosyl)purine (10) which upon catalytic hydrogenation and subsequent de-N-benzoylation produced the title compound, 12. The sensitivity of certain nitro intermediates towards alkali is commented upon.

Syothesis of 3-Deoxy-3-nitro-D-xylose

1971 ◽  
Vol 49 (19) ◽  
pp. 3238-3239 ◽  
Author(s):  
Jan Kovář ◽  
Hans H. Baer
Keyword(s):  
Acid Hydrolysis ◽  
Title Compound ◽  
Periodate Oxidation ◽  
Borohydride Reduction ◽  
Hydrolysis Of

Crystalline 3-deoxy-3-nitro-α-D-xylose (5) was obtained in 40% over-all yield by periodate oxidation of 3-deoxy-1,2-O-isopropylidene-3-nitro-α-D-glucofuranose (2) followed by borohydride reduction and acid hydrolysis. In addition to the intermediate 3-deoxy-1,2-O-isopropylidene-3-nitro-α-D-xylofuranose (4), a small amount of an isomer probably having the D-ribo configuration was isolated. The title compound (5) was also obtained by hydrolysis of its methyl β-pyranoside (1).

Synthesis of (15E)-17β-hydroxy-5α-androstane-3,15-dione 15-[O-(Carboxymethyl)]oxime, New Hapten for Dihydrotestosterone (17β-hydroxy-5α-androstan-3-one)

1997 ◽  
Vol 62 (10) ◽  
pp. 1642-1649 ◽  
Author(s):  
Ivan Černý ◽  
Tereza Slavíková ◽  
Vladimír Pouzar
Keyword(s):  
Hydroxy Group ◽  
Carboxy Group ◽  
Title Compound ◽  
Oxidative Cleavage ◽  
Hydroxy Derivative ◽  
Borohydride Reduction ◽  
Protecting Group ◽  
Free Hydroxy Group

Addition of 4-methoxybenzyl alcohol to 3β-hydroxy-5α-androst-15-en-17-one gave the mixture of isomeric 15-(4-methoxyphenyl)methoxy derivatives from which, after acetylation and chromatography, the major 15β isomer was separated. Borohydride reduction gave 17β-hydroxy derivative which was protected as methoxymethyl ether. Oxidative cleavage of protecting group at position 15 and the subsequent Jones oxidation afforded corresponding 15-ketone. Its oximation with O-(carboxymethyl)hydroxylamine, deacetylation and methylation with diazomethane gave protected O-(carboxymethyl)oxime derivative with free hydroxy group at position 3. Its oxidation afforded dihydrotestosterone derivative and successive deprotection of position 17 and of carboxy group led to final (15E)-17β-hydroxy-5α-androstane-3,15-dione 15-[O-(carboxymethyl)]oxime. The title compound was designed as dihydrotestosterone hapten for heterologous radioimmunoassays.

scholarly journals A glucan from active dry baker’s yeast (Saccharomyces cerevisiae): A chemical and enzymatic investigation of the structure

2003 ◽  
Vol 68 (11) ◽  
pp. 805-809 ◽  
Author(s):  
Dragan Zlatkovic ◽  
Dragica Jakovljevic ◽  
Djordje Zekovic ◽  
Miroslav Vrvic
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Optical Rotation ◽  
Linear Chain ◽  
Periodate Oxidation ◽  
Methylation Analysis ◽  
Yeast Saccharomyces Cerevisiae ◽  
New Approach ◽  
Main Structural Feature ◽  
Or Groups

The structure of a polysaccharide consisting of D-glucose isolated from the cell-wall of active dry baker?s yeast (Saccharomyces cerevisiae) was investigated by using methylation analysis, periodate oxidation, mass spectrometry, NMR spectroscopy, and enzymic hydrolysis, as a new approach in determination of structures. The main structural feature of the polysaccharide deduced on the basis of the obtained results is a linear chain of (1?3)-linked ?-D-glucopyranoses, a part of which is substituted through the positions O-6. The side units or groups are either a single D-glucopyranose or (1?3)-?-oligoglucosides, linked to the main chaing through (1?6)-glucosidic linkages. The low optical rotation as well as the 13C-NMR and FTIR spectra suggest that the glycosidic linkages are in the ?-D-configuration.

Colorimetric assay of glycoprotein glycation free of interference from glycosylation residues

1993 ◽  
Vol 39 (11) ◽  
pp. 2309-2311 ◽  
Author(s):  
D M Kennedy ◽  
A W Skillen ◽  
C H Self
Keyword(s):  
Sodium Borohydride ◽  
Serum Proteins ◽  
Colorimetric Assay ◽  
Periodate Oxidation ◽  
Borohydride Reduction ◽  
Glycan Chain

Abstract We have developed a colorimetric assay for determining the degree of glycation of serum proteins that is unaffected by glycosylation residues. This was accomplished by reducing the proteins with sodium borohydride prior to periodate oxidation. Previous periodate-based methods, which offer several advantages over other glycation assays, cannot determine glycoprotein glycation because interference from sialic residues in the glycan chain can lead to overestimation of the amount of glycation products. Without reduction, glycation of fetuin was double that of asialofetuin glycated under identical conditions. We found that borohydride reduction before periodate oxidation increases the amount of formaldehyde released in proportion to the extent of glycation, irrespective of the degree of glycosylation. Using two glycoproteins and an unglycosylated protein, we showed how measurement of the formaldehyde increase enables the extent of glycoprotein glycation to be determined without removal of interfering sugars.

scholarly journals The chemistry of the collagen cross-links. The characterization of Fraction C, a possible artifact produced during the reduction of collagen fibres with borohydride

1973 ◽  
Vol 135 (4) ◽  
pp. 657-665 ◽  
Author(s):  
Simon P. Robins ◽  
Allen J. Bailey
Keyword(s):  
Aldol Condensation ◽  
Condensation Product ◽  
Reduced Form ◽  
Borohydride Reduction ◽  
Cross Link ◽  
Collagen Fibres ◽  
Isolation And Identification ◽  
Cross Links

The present paper describes the isolation and identification of a major radioactive component of borotritide-reduced collagen, previously designated Fraction C. The derived structure for the compound confirms that it is identical with the ‘post-histidine’ component described by Tanzer et al. (1973) and given the trivial name histidino-hydroxymerodesmosine. Detailed studies of the effects of acid pH on the formation of Fraction C after borohydride reduction demonstrated the apparent lability of the non-reduced form, thus confirming our previous findings (Bailey & Lister, 1968). Inhibition of the formation of this component by the acid treatment appears to be due to protonation of the histidine imidazole group. Since the only new component formed on reduction of the acid-treated fibres was the reduced aldol condensation product, these results indicate that neither the histidine nor the hydroxylysine residues can be involved in covalent linkage with the aldol condensation product in the native fibre. It is suggested therefore that the proposed non-reduced aldimine form of Fraction C does not exist as an intermolecular cross-link in vivo. Thus the presence of histidino-hydroxymerodesmosine as a tetrafunctional cross-link in reduced collagen fibres is a result of a base-catalysed reaction promoted by the borohydride-reduction procedure and this component must therefore be considered as an artifact.

The synthesis of D-angolosamine

1977 ◽  
Vol 55 (6) ◽  
pp. 1100-1103 ◽  
Author(s):  
Hans H. Baer ◽  
Fawzy F. Z. Georges
Keyword(s):  
Sodium Borohydride ◽  
Catalytic Hydrogenation ◽  
Title Compound ◽  
Amino Glycoside ◽  
Starting Point ◽  
Simplified Procedure

The synthesis of 2,3,6-trideoxy-3-dimethylamino-D-arabino-hexose hydrochloride (10) (D-angolosamine, a constituent of the antibiotic, angolamycin) is described. First, a simplified procedure for the preparation of methyl 6-deoxy-α-D-glucopyranoside from methyl α-D-glucopyranoside is recorded. The deoxy derivative served as the starting point for sequential preparation of methyl 3,6-dideoxy-3-nitro-α-D-glucopyranoside (1), its 2,4-diacetate (2), its 4-monoacetate (3), its 2-O-mesyl-4-acetate (4), its 2-mesylate (5), and methyl 2,3,6-trideoxy-3-nitro-α-D-erythro-hex-2-enopyranoside (6) essentially according to procedures previously established (in part, in the L-series). Treatment of 5 or 6 with sodium borohydride produced methyl 2,3,6-trideoxy-3-nitro-α-D-arabino-hexopyranoside (7). Catalytic hydrogenation of 7 gave the corresponding 3-amino glycoside hydrochloride (8) which was hydrolyzed to furnish 3-amino-2,3,6-trideoxy-D-arabino-hexose hydrochloride (9) (D-acosamine, the enantiomer of a component of the antibiotic, actinoidin). N,N-Dimethylation of 8 followed by hydrolysis afforded the crystalline title compound (10).

A Stereospecific Synthesis of L-Desosamine

1974 ◽  
Vol 52 (1) ◽  
pp. 122-124 ◽  
Author(s):  
Hans H. Baer ◽  
Chung-Wai Chiu
Keyword(s):  
Acid Hydrolysis ◽  
Nitro Group ◽  
Catalytic Hydrogenation ◽  
Glycosidic Bond ◽  
Stereospecific Synthesis ◽  
Borohydride Reduction ◽  
Amino Glycoside ◽  
Hydrolysis Of

L-Desosamine (3,4,6-trideoxy-3-dimethylamino-L-xylo-hexose), the enantiomer of a widely distributed antibiotics component, was synthesized by borohydride reduction of methyl 3,4,6-trideoxy-3-nitro-α-L-erythro-hex-3-enopyranoside followed by catalytic hydrogenation of the nitro group, N,N-dimethylation of the resulting saturated amino glycoside, and acid hydrolysis of the glycosidic bond.

Structural studies of organoboron compounds. LIII. N,N-Diethylhydroxylamine-(O-B)1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5- boratabicyclo[3.3.0]octane

1992 ◽  
Vol 70 (7) ◽  
pp. 2022-2026 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Hydrogen Bond ◽  
Least Squares ◽  
Title Compound ◽  
Condensation Product ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
High Yield ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths

Reaction of the condensation product of N,N′-dimethyl-N,N′-dihydroxymethanediamine and phenylboronic acid with N,N-diethylhydroxylamine gives N,N-diethylhydroxylamine(O-B)1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane [3-(2-ethyl-1-oxa-2-azoniabutyl)-1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3,5-diboratabicyclo[3.3.0]octane, 3] in high yield. Crystals of 3 are orthorhombic, a = 11.8132(11), b = 15.4768(11), c = 11.7325(16) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.039 and Rw = 0.044 for 1729 reflections with I ≥ 2σ(I). The title compound is the second example of this recently characterized class of O-B coordinated hydroxylamine complexes, stabilized by an intramolecular [Formula: see text] hydrogen bond [Formula: see text]. Bond lengths about boron are: B—O(N) = 1.482(4)–1.526(4), B—O(B) = 1.412(4) and 1.420(4), B—N = 1.712(4), B—C = 1.591(5) and 1.602(5) Å.

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