scholarly journals Change in specificity of glycosidase inhibition by N-alkylation of amino sugars

1989 ◽  
Vol 258 (2) ◽  
pp. 613-615 ◽  
Author(s):  
S al Daher ◽  
G Fleet ◽  
S K Namgoong ◽  
B Winchester
Keyword(s):  
Inhibitory Activity ◽  
Human Liver ◽  
Amino Sugar ◽  
Amino Sugars ◽  
Weak Inhibitor ◽  
First Report ◽  
Glycosidase Inhibitor ◽  
Ring Nitrogen ◽  
Glycosidase Inhibition

The synthetic amino sugar 1,4-dideoxy-1,4-imino-L-allitol (DIA) is a moderately good inhibitor of human liver alpha-D-mannosidases and a weak inhibitor of alpha-L-fucosidase, N-acetyl-beta-D-hexosaminidase and beta-D-mannosidase. Methylation of the ring nitrogen of DIA markedly decreases the inhibition of all the glycosidases except N-acetyl-beta-D-hexosaminidase. N-Benzylation of DIA essentially abolishes all inhibitory activity, except towards alpha-L-fucosidase, which is more strongly inhibited than by either DIA or N-methyl-DIA. This is the first report of a change of specificity of inhibition of a glycosidase inhibitor by substitution of the ring nitrogen.

scholarly journals Divergent Accumulation of Microbial Residues and Amino Sugars in Loess Soil after Six Years of Different Inorganic Nitrogen Enrichment Scenarios

2021 ◽  
Vol 11 (13) ◽  
pp. 5788
Author(s):  
Dominic Kwadwo Anning ◽  
Zhilong Li ◽  
Huizhen Qiu ◽  
Delei Deng ◽  
Chunhong Zhang ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Inorganic Nitrogen ◽  
Amino Sugar ◽  
N Fertilization ◽  
Biochemical Properties ◽  
Sugar Accumulation ◽  
Amino Sugars ◽  
N Enrichment ◽  
Over Time ◽  
Microbial Residues

Amino sugars are key microbial biomarkers for determining the contribution of microbial residues in soil organic matter (SOM). However, it remains largely unclear as to what extent inorganic nitrogen (N) fertilization can lead to the significant degradation of SOM in alkaline agricultural soils. A six-year field experiment was conducted from 2013 to 2018 to evaluate the effects of chronic N enrichment on microbial residues, amino sugars, and soil biochemical properties under four nitrogen (urea, 46% N) fertilization scenarios: 0 (no-N, control), 75 (low-N), 225 (medium-N), and 375 (high-N) kg N ha−1. The results showed that chronic N enrichment stimulated microbial residues and amino sugar accumulation over time. The medium-N treatment increased the concentration of muramic acid (15.77%), glucosamine (13.55%), galactosamine (18.84%), bacterial residues (16.88%), fungal residues (11.31%), and total microbial residues (12.57%) compared to the control in 2018; however, these concentrations were comparable to the high-N treatment concentrations. The ratio of glucosamine to galactosamine and of glucosamine to muramic acid decreased over time due to a larger increase in bacterial residues as compared to fungal residues. Microbial biomass, soil organic carbon, and aboveground plant biomass positively correlated with microbial residues and amino sugar components. Chronic N enrichment improved the soil biochemical properties and aboveground plant biomass, which stimulated microbial residues and amino sugar accumulation over time.

scholarly journals Flavonoids from Anoectochilus annamensis and their Anti-inflammatory Activity

2016 ◽  
Vol 11 (5) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Tran Minh Hoi ◽  
Tran Van Thai ◽  
Chu Thi Thu Ha ◽  
Ha Thi Van Anh ◽  
Phan Xuan Binh Minh ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Biological Activity ◽  
Chemical Composition ◽  
Inhibitory Activity ◽  
Inflammatory Mediator ◽  
Methanol Extract ◽  
Inflammatory Activity ◽  
Raw264.7 Cells ◽  
First Report ◽  
Aerial Parts

One new flavonol diglycoside, 4′,5-dihydroxy-3,3′,7-trimethoxyflavone 4′- O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (1), and two known compounds (2–3) were isolated from the methanol extract of Anoectochilus annamensis Aver. aerial parts. The effects were evaluated of all isolated compounds (1–3) on LPS-induced production of the inflammatory mediator nitric oxide (NO) by RAW264.7 cells. 4′,5-Dihydroxy-3,3′,7-trimethoxyflavone (2) was the most active while the addition of a rutinoside at C-4′ (compound 1) decreased the inhibitory activity. This is the first report on the chemical composition and biological activity of A annamensis.

Comprehensive assessment of precursors, diagenesis, and reactivity to water treatment of dissolved and colloidal organic matter

2004 ◽  
Vol 4 (4) ◽  
pp. 1-9 ◽  
Author(s):  
J.A. Leenheer
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Condensed Tannins ◽  
Drinking Water Treatment ◽  
Amino Sugar ◽  
Amino Sugars ◽  
Research Approach ◽  
Soil Aquifer Treatment ◽  
Treatment Processes ◽  
High Yields

A comprehensive isolation, fractionation, and characterization research approach was developed for dissolved and colloidal organic matter (DOM) in water, and it was applied to various surface- and groundwaters to assess DOM precursors, DOM diagenesis, and DOM reactivity to water treatment processes. Major precursors for natural DOM are amino sugars, condensed tannins, and terpenoids. Amino sugar colloids derived from bacterial cell walls are incompletely removed by drinking water treatment and foul reverse osmosis membranes, but are nearly quantitatively removed by soil/aquifer treatment. When chlorinated, amino sugars produce low yields of regulated disinfection by-products (DBPs) but they produce significant chlorine demand that is likely caused by chlorination of free amino groups. Condensed tannins are major precursors for ,blackwater- DOM such as that found in the Suwannee River. This DOM produces high yields of DBPs upon chorination, and is efficiently removed by coagulation/flocculation treatment. Terpenoid-derived DOM appears to be biologically refractory, infiltrates readily into groundwater with little removal by soil/aquifer treatment, gives low DBP-yields upon chlorination and is poorly removed by coagulation/flocculation treatments. Peptides derived from proteins are major components of the base DOM fraction (10% or less of the mass of DOM), and this fraction produces large yields of haloacetonitriles upon chorination.

scholarly journals Correlation between anthracycline structure and human DNA ligase inhibition

1991 ◽  
Vol 279 (1) ◽  
pp. 141-146 ◽  
Author(s):  
G Ciarrocchi ◽  
M Lestingi ◽  
M Fontana ◽  
S Spadari ◽  
A Montecucco
Keyword(s):  
Inhibitory Activity ◽  
Amino Sugar ◽  
Dna Ligase ◽  
Amino Groups ◽  
Maximal Inhibition ◽  
General Finding ◽  
Human Dna ◽  
Anti Tumour Activity ◽  
Tumour Activity

A total of 19 anthracycline derivatives were tested for their ability to interfere in vitro with the action of the human replicative DNA ligase. Only those with the sugar devoid of unmodified amino groups or with large configurational modifications were found to be inactive. Maximal inhibition of DNA-joining activity was found to require a 4′-deoxy-3′-amino sugar. Self-adenylation of DNA ligase was largely insensitive to these drugs. An important general finding is that slight modifications of the anthracycline structure have pronounced effects on DNA-ligase-inhibitory activity and might be related to the specificity of anthracycline anti-tumour activity.

scholarly journals Determining the IC50 Values for Vorozole and Letrozole, on a Series of Human Liver Cytochrome P450s, to Help Determine the Binding Site of Vorozole in the Liver

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Lendelle Raymond ◽  
Nikita Rayani ◽  
Grace Polson ◽  
Kylie Sikorski ◽  
Ailin Lian ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
High Throughput Screening ◽  
Human Liver ◽  
Potent Inhibitor ◽  
Cytochrome P450s ◽  
Third Generation ◽  
Weak Inhibitor ◽  
Liver Cytochrome ◽  
Ic50 Values ◽  
Screening Assays

Vorozole and letrozole are third-generation aromatase (cytochrome P450 19A1) inhibitors. [11C]-Vorozole can be used as a radiotracer for aromatase in living animals but when administered by IV, it collects in the liver. Pretreatment with letrozole does not affect the binding of vorozole in the liver. In search of finding the protein responsible for the accumulation of vorozole in the liver, fluorometric high-throughput screening assays were used to test the inhibitory capability of vorozole and letrozole on a series of liver cytochrome P450s (CYP1A1, CYP1A2, CYP2A6, and CYP3A4). It was determined that vorozole is a potent inhibitor of CYP1A1 (IC50 = 0.469 μM) and a moderate inhibitor of CYP2A6 and CYP3A4 (IC50 = 24.4 and 98.1 μM, resp.). Letrozole is only a moderate inhibitor of CYP1A1 and CYP2A6 (IC50 = 69.8 and 106 μM) and a very weak inhibitor of CYP3A4 (<10% inhibition at 1 mM). Since CYP3A4 makes up the majority of the CYP content found in the human liver, and vorozole inhibits it moderately well but letrozole does not, CYP3A4 is a good candidate for the protein that [11C]-vorozole is binding to in the liver.

scholarly journals Structural and functional analysis of the solute-binding protein UspC from Mycobacterium tuberculosis that is specific for amino sugars

Open Biology ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 160105 ◽  
Author(s):  
Elizabeth Fullam ◽  
Ivan Prokes ◽  
Klaus Fütterer ◽  
Gurdyal S. Besra
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Abc Transporters ◽  
Binding Protein ◽  
Functional Characterization ◽  
Amino Sugar ◽  
Amino Sugars ◽  
Environmental Niche ◽  
Intracellular Infection ◽  
Shift Analysis ◽  
Binding Cleft

Mycobacterium tuberculosis ( Mtb ), the aetiological agent of tuberculosis, has evolved to scavenge nutrients from the confined environment of host macrophages with mycobacterial ATP-binding cassette (ABC) transporters playing a key role in nutrient acquisition. Mtb -UspC (Rv2318) is the solute-binding protein of the essential transporter UspABC, one of four Mtb ABC transporters implicated by homology in sugar acquisition. Herein, we report the structural and functional characterization of Mtb -UspC. The 1.5 Å resolution structure of UspC reveals a two subdomain architecture that forms a highly acidic carbohydrate-substrate binding cleft. This has allowed a distinct preference of Mtb -UspC for amino sugars as determined by thermal shift analysis and solution saturation transfer difference-NMR. Taken together our data support the functional assignment of UspABC as an amino-sugar transporter. Given the limited availability of carbohydrates within the phagosomal environmental niche during Mtb intracellular infection, our studies suggest that UspABC enables Mtb to optimize the use of scarce nutrients during intracellular infection, linking essentiality of this protein to a potential role in recycling components of cell-wall peptidoglycan.

Preparation of bisulphite addition compounds of 5-Amino-5-deoxy-D-xylose

1966 ◽  
Vol 19 (4) ◽  
pp. 667 ◽  
Author(s):  
DL Ingles
Keyword(s):  
Amino Acid ◽  
Free Amino ◽  
Amino Sugar ◽  
Barium Hydroxide ◽  
Free Sugar ◽  
Amino Sugars ◽  
Addition Compound ◽  
Derivatives Of

Sulphurous acid alone and in admixture with other stronger acids has been used to hydrolyse 5-amino, 5-N-cyclohexylamino, and 5-N-piperidino derivatives of 5-deoxy-l,2-O-isopropylidene-D-xylose. The bisulphite addition compounds of the corresponding amino sugars were thus isolated. Similarly, methyl 5-amino-5-deoxy- 2,3-O-isopropylidene-D-riboside was hydrolysed to yield the bisulphite addition compound of 5-amino-5-deoxy-D-ribose. Treatment of the bisulphite addition compound of 5-amino-5-deoxy-D-xylose with barium hydroxide gave the free amino sugar as a syrup in 96% yield. Removal of bisulphite from the addition compound of 5-X-cyclohexylamino-5-deoxy-D-xylose gave the free sugar in 30% yield together with an amino acid (XVI).

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