Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMINO SUGARS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed2000

Preparation and structure determination of two sugar amino acids via corresponding hydantoin derivatives.

(4R)-2,3-O-Isopropylidene-methylspiro[4,6-dideoxy-alpha-L-lyxo+ ++-hexopyranosid-4,5'-imidazolidin]-2',4'-dione and (4R)-2,3-O-isopropylidene-methylspiro[4,6-dideoxy-beta-D-ribo-h exopyranosid-4,5'-imidazolidin]-2',4'-dione were prepared under various reaction conditions starting from methyl 6-deoxy-2,3-O-isopropylidene-alpha-L-lyxo-hexopyranosid-4-++ +ulose. Corresponding alpha-amino acids methyl (4R)-4-amino-4-C-carboxy-4,6-dideoxy-alpha-L-lyxo-hexopyranosid e and methyl (4R)-4-amino-4-C-carboxy-4,6-dideoxy-beta-D-ribo-hexopyranoside were obtained from the above hydantoins by selective acid hydrolysis of the isopropylidene group, followed by basic hydrolysis of the hydantoin ring. The crystal structures of both hydantoin derivatives are also presented.

Amino Acids↗
PubMed1976

An approach to the synthesis of branched-chain amino sugars from C-methylene sugars.

The reaction of 1,2:5,6-di-O-isopropylidene-3-C-methylene-alpha-D-ribo-hexofuranose (4) with mercuric azide in hot 50% aqueous tetrahydrofuran yielded, after reductive demercuration, 3-azido-3-deoxy-1,2:5,6-di-O-isopropylidene-3-C-methyl-alpha-D-glucofuranose (5). Partial, acid hydrolysis of 5 afforded the diol 7, which gave 3-azido-3-deoxy-1,2-O-isopropylidene-5,6-di-O-methanesulphonyl-3-C-methyl-alpha-D-glucofuranose (8) on sulphonylation. On hydrogenation over a platinum catalyst and N-acetylation, the dimethanesulphonate 8 furnished 3,6-acetyleprimino-3,6-dideoxy-1,2-O-isopropylidene-5-O-methanesulphonyl-3-C-methyl-alpha-D-glucofuranose (9), which was also prepared by an analogous sequence of reactions on 3-azido-3-deoxy-1,2-O-isopropylidene-5-O-methanesulphonyl-3-C-methyl-6-O-toluene-p-sulphonyl-alpha-D-glucofuranose (13). The formation of the N-acetylepimine 9 establishes the D-gluco configuration for 5. 1,2-O-Isopropylidene-3-C-methylene-alpha-D-ribo-hexofuranose (20) reacted with mercuric azide in aqueous tetrahydrofuran at approximately 85 degrees to give 3,6-anhydro-1,2-O-isopropylidene-3-C-methyl-alpha-D-glucofuranose (22) as a result of intramolecular participation by the C-6 hydroxyl group in the initial intermediate.

Chemical Phenomena↗
PubMed1996

Stereoselective Synthesis of Differentially Protected Derivatives of the Higher Amino Sugars Destomic Acid and Lincosamine from Serine and Threonine.

The aminoheptose destomic acid (3.5) and the aminooctose lincosamine (6.8) were synthesized in protected form by parallel sequences starting from the oxazolidine derivatives 2.4 and 5.1 of N-CBz serinal and N-BOC threoninal. The parallel sequences feature BF(3)-promoted addition of the (R)-gamma-OTBS allylic stannane 2.8 to the homologated enals 2.7 and 5.4, respectively, followed by stereoselective bis-dihydroxylation of the derived bis-OTBS ethers 2.10 and 5.6. Regioselective oxidative cleavage of the less hindered vicinal diol moieties of these intermediates led to the gamma-lactols 3.2 and 5.8, respectively. In the former case, treatment with TBAF and subsequent hydrolysis removed the OTBS and acetonide protecting groups affording the destomic acid precursor, pyranose 3.4. Lactol 5.8 was converted to the pyranoside 6.3 by silyl ether cleavage, acidic hydrolysis, and bis-acetonide formation. Inversion of the C7 hydroxyl grouping was effected by the Mitsunobu methodology with p-NO(2)C(6)H(4)CO(2)H. Subsequent hydrolysis, cleavage of the BOC grouping, and N-acetylation afforded the lincosamine derivative 6.7.

Journal Article↗
PubMed1995

Tritium labelling of amino sugars at C-2 by alkaline epimerization in tritiated water.

N-Acetyl-D-[2-3H]glucosamine was synthesized from N-acetyl-D-mannosamine by alkaline 2-epimerization in pyridine containing 3H2O and nickelous acetate. The reaction involves reversible formation of an enol intermediate and therefore also resulted in incorporation of tritium into N-acetylmannosamine. After completed reaction, the two N-acetylhexosamines were separated from other radioactive products and Morgan-Elson chromogens by chromatography on a column of Sephadex G-10, which was eluted with 10% ethanol, and were then separated from each other by chromatography on Sephadex G-15 in 0.27 M sodium borate (pH 7.8). The location of the incorporated tritium was established by treatment of the N-acetylhexosamines with borate under the conditions of the Morgan-Elson reaction, which converts the sugars to Kuhn's chromogen I with concomitant loss of the C-2 hydrogen. As expected, this treatment resulted in the formation of 3H2O, indicating that the tritium was located at C-2. [2-3H]Glucosamine was prepared by acid hydrolysis of the labelled N-acetylglucosamine and was converted to [2-3H]glucosamine 6-phosphate by incubation with hexokinase and ATP. The sugar phosphate was used as a substrate for glucosamine 6-phosphate deaminase (isomerase, EC 5.3.1.10) in a simple 3H2O release assay.

Acetylglucosamine↗
PubMed1980

Amino-sugar transport systems of Escherichia coli K12.

Glucosamine, mannose and 2-deoxyglucose enter Escherichia coli by the phosphotransferase system coded for by the gene ptsM. The glucosamine- and mannose-negative, deoxyglucose-resistant phenotype of ptsM mutants can be suppressed by a mutation mapping near ptsG that allows constitutive expression of the glucose phosphotransferase coded for by the gene ptsG. N-Acetylglucosamine enters E. coli by two distinct phosphotransferase systems (White, 1970). One of these is the PtsM system, the other is coded for by a gene which maps near the nagA,B genes at about min 15 on the E. coli chromosome. We propose that this gene be designated ptsN. Strains with either of these components of the phosphotransferase system will utilize N-acetylglucosamine as sole carbon source.

Acetylglucosamine↗