scholarly journals Chemical synthesis of all-trans-β-retinoyl phosphate

1976 ◽  
Vol 159 (3) ◽  
pp. 799-801 ◽  
Author(s):  
J P Frot-Coutaz ◽  
L M de Luca
Keyword(s):  
Retinoic Acid ◽  
Chemical Synthesis ◽  
Cellulose Acetate ◽  
Silica Gel ◽  
Absorption Maximum ◽  
Ammonium Acetate ◽  
Deae Cellulose ◽  
Thin Layers ◽  
Molar Ratio ◽  
Chloroform Methanol

all-trans-β-Retinoic acid is phosphorylated to retinoyl phosphate by bis(triethylamine) phosphate with yields of 10-15%. The product is soluble in methanol and is eluted from DEAE-cellulose acetate at a concentration of 0.1M-ammonium acetate in 99% (v/v) methanol. Its phosphate/retinoic acid molar ratio is 1. Retinoyl phosphate has an absorption maximum at 360nm in methanol, whereas retinoic acid has a maximum at 350 nm. The compound is hydrolysed at pH2 and pH13 for 20 min at 37 degrees C, but is relatively stable under the same conditions at pH4, 6, 8 and 10. Retinoyl phosphate (RF 0.1) can be separated from retinyl phosphate (RF 0.2) by chromatography on thin layers of silica gel in chloroform/methanol/water (60:25:4, by vol.).

scholarly journals The formation of lipid-linked sugars as intermediates in glycoprotein synthesis in rabbit mammary gland

1978 ◽  
Vol 170 (2) ◽  
pp. 273-283 ◽  
Author(s):  
Brian K. Speake ◽  
David A. White
Keyword(s):  
Ammonium Acetate ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Total Radioactivity ◽  
Glycoprotein Synthesis ◽  
Molecular Weights ◽  
Oligosaccharide Moiety ◽  
Chloroform Methanol ◽  
Mild Acid

1. The incorporation of d-[1-14C]mannose, d-[2-3H]mannose and N-acetyl-d-[1-14C]-glucosamine into glycoproteins and lipid-linked intermediates of mammary explants obtained from lactating rabbits was studied. The amount of radioactivity incorporated into lipid-linked intermediates was very low compared with the incorporation into protein. Most of the radioactivity incorporated into the chloroform/methanol-soluble fraction was present as neutral lipid. Radioactivity from d-[2-3H]mannose was incorporated mainly into the fatty acid moiety, whereas radioactivity from d-[1-14C]mannose and N-acetyl-d-[1-14C]glucosamine was present in the glycerol moiety of triacylglycerol. 2. The labelled lipid-linked intermediate that was soluble in chloroform/methanol/water (10:10:3, by vol.) was partially characterized and was found to exhibit properties characteristic of an oligosaccharide linked to lipid via a pyrophosphate bridge. It migrated largely as a single zone of radioactivity on t.l.c. and was eluted from a column of DEAE-cellulose acetate as a single peak by 50mm-ammonium acetate. 3. The oligosaccharide moiety was released from the lipid by mild acid hydrolysis. The size of the oligosaccharide was estimated by paper chromatography to be 10 or 11 monosaccharide units. 4. d-[1-14C]Mannose was incorporated largely into glycopeptides with molecular weights in the range 40000–80000, as determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. Label from N-acetyl-d-[1-14C]glucosamine was incorporated into a glycopeptide with an electrophoretic mobility identical with that of rabbit casein (mol.wt. 32000) as well as into glycopeptides of higher molecular weight. 5. Approx. 50% of the total radioactivity in the protein labelled from N-acetyl-d-[1-14C]glucosamine was present as galactosamine, a component of the carbohydrate portion of rabbit casein. No labelled galactosamine was present in the lipid-linked oligosaccharide labelled from N-acetyl-d-[1-14C]glucosamine. It thus appears that the lipid-linked oligosaccharide is not involved in the glycosylation of casein.

Electrospun nanofibrous membranes of cellulose acetate containing hydroxyapatite co-doped with Ag/Fe: morphological features, antibacterial and degradation of methylene blue from aqueous solutions

2021 ◽  
Author(s):  
Ahmed Esmail Shalan ◽  
M. Afifi ◽  
M.M. El-Desoky ◽  
M.k Ahmed
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Cellulose Acetate ◽  
Morphological Features ◽  
Molar Ratio ◽  
Electrospinning Technique ◽  
Nanofiber Membranes ◽  
Nanofibrous Membranes ◽  
Co Doped

Cellulose acetate nanofiber membranes containing hydroxyapatite co-doped with Ag/Fe were efficaciously attained through the electrospinning technique. Different molar ratio compositions of hydroxyapatite co-doped with Ag/Fe in the structure of the...

scholarly journals Polysaccharide Derived from Nelumbo nucifera Lotus Plumule Shows Potential Prebiotic Activity and Ameliorates Insulin Resistance in HepG2 Cells

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1780
Author(s):  
Bao Le ◽  
Pham-Thi-Ngoc Anh ◽  
Seung-Hwan Yang
Keyword(s):  
Insulin Resistance ◽  
Hepg2 Cells ◽  
Structural Characteristics ◽  
Physicochemical Characterization ◽  
Deae Cellulose ◽  
Hot Water ◽  
Nelumbo Nucifera ◽  
Molar Ratio ◽  
Prebiotic Activity ◽  
Insulin Resistant

Polysaccharides are key bioactive compounds in lotus plumule tea, but their anti-diabetes activities remain unclear. The purpose of this study was to investigate the prebiotic activities of a novel polysaccharide fraction from the Nelumbo nucifera lotus plumule, and to examine its regulation of glucose metabolism in insulin-resistant HepG2 cells. The N. nucifera polysaccharide (NNP) was purified after discoloration, hot water extraction, ethanol precipitation, and DEAE-cellulose chromatography to obtain purified polysaccharide fractions (NNP-2). Fourier transform infrared spectroscopy was used to analyze the main structural characteristics and functional group of NNP-2. Physicochemical characterization indicated that NNP-2 had a molecular weight of 110.47 kDa and consisted of xylose, glucose, fructose, galactose, and fucose in a molar ratio of 33.4:25.7:22.0:10.5:8.1. The prebiotic activity of NNP-2 was demonstrated in vitro using Lactobacillus and Bifidobacterium. Furthermore, NNP-2 showed bioactivity against α-glucosidase (IC50 = 97.32 µg/mL). High glucose-induced insulin-resistant HepG2 cells were used to study the effect of NNP-2 on glucose consumption, and the molecular mechanism of the insulin transduction pathway was studied using RT-qPCR. NNP-2 could improve insulin resistance by modulating the IRS1/PI3K/Akt pathway in insulin-resistant HepG2 cells. Our data demonstrated that the Nelumbo nucifera polysaccharides are potential sources for nutraceuticals, and we propose functional food developments from the bioactive polysaccharides of N. nucifera for the management of diabetes.

scholarly journals Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Hang Xu ◽  
Tianlong Yu ◽  
Mei Li
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Vinyl Acetate ◽  
Silica Gel ◽  
Catalyst Activity ◽  
Catalyst Layer ◽  
Space Velocity ◽  
Molar Ratio ◽  
Vinyl Acetate Monomer ◽  
Adsorption Desorption

Ionic liquid containing active ingredient Zn(CH3COO)2was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC) which was used to synthesize vinyl acetate monomer (VAM). SILC was characterized by1HNMR, FT-IR, TGA, BET, and N2adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc) conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc) selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV). The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

Biosynthesis of glucosyl monophosphoryl undecaprenol and its role in lipoteichoic acid biosynthesis

1982 ◽  
Vol 152 (2) ◽  
pp. 616-625
Author(s):  
D J Mancuso ◽  
T H Chiu
Keyword(s):  
Thin Layer ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Lipoteichoic Acid ◽  
Molar Ratio ◽  
Streptococcus Sanguis ◽  
Chromatographic Profile ◽  
Hydrolysis Of ◽  
Cellulose Column

A glucophospholipid was detected in an incubation mixture containing UDP-glucose, MgCl2, ATP, and a particulate enzyme prepared from Streptococcus sanguis. The synthesis of this lipid was inhibited strongly by UDP and moderately by UMP. The molar ratio of glucose to phosphate in the purified lipid was found to be 1:1. Glucose and glucose 1-phosphate were released by mild alkaline hydrolysis of the glucophospholipid. The lipid produced by mild acid degradation of the purified lipid yielded a thin-layer chromatographic profile similar to that of acid-treated undecaprenol. One of the minor components exhibited the same mobility as untreated undecaprenol. To characterize further the lipid moiety of the glucophospholipid, a polyisoprenol was purified from the neutral lipid of S. sanguis. The polyisoprenol was converted in the presence of ATP, UDP-glucose, and the particulate enzyme into a lipid which exhibited the same thin-layer chromatographic mobility as the glucophospholipid. The structure of the polyisoprenol was determined by nuclear magnetic resonance and mass spectrometry to be an undecaprenol with an internal cis-trans ratio of 7:2. These results indicate that the glucophospholipid is glucosyl monophosphoryl undecaprenol. The glucosyl moiety of the glucophospholipid was shown to be incorporated in the presence of the particulate enzyme into a macromolecule which was characterized as a lipoteichoic acid by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and DEAE-cellulose column chromatography. This result indicates that glucosyl monophosphoryl undecaprenol is the direct glucosyl donor in the synthesis of lipoteichoic acid.

scholarly journals Dinuclear Copper(II) Complexes with Schiff Bases Derived from 2-Hydroxy-5-Methylisophthalaldehyde and Histamine or 2-(2-Aminoethyl)pyridine and Their Application as Magnetic and Fluorescent Materials in Thin Film Deposition

2020 ◽  
Vol 21 (13) ◽  
pp. 4587
Author(s):  
Magdalena Barwiolek ◽  
Anna Kaczmarek-Kędziera ◽  
Tadeusz M. Muziol ◽  
Dominika Jankowska ◽  
Julia Jezierska ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Thin Film Deposition ◽  
Chain Structure ◽  
Film Deposition ◽  
Thin Layers ◽  
Molar Ratio ◽  
Structural Examination ◽  
Thermal Methods ◽  
Dimeric Unit ◽  
Pyramidal Geometry

Two Cu(II) complexes, 1 and 2, with tridentate Schiff bases derived from 2-hydroxy-5-methylisophthalaldehyde and histamine HL1 or 2-(2-aminoethyl)pyridine HL2, respectively, were obtained and characterized by X-ray crystallography, spectroscopic (UV-vis, fluorescence, IR, and EPR), magnetic, and thermal methods. Despite the fact that the chelate formed by the NNO ligand donors (C26-C25H2-C24H2-N23=C23H-C22-C19Ph(O1)-C2(Ph)-C3H=N3-C4H2-C5H2-C6 fragment) are identical, as well as the synthesis of Cu(II) complexes (Cu:L = 2:1 molar ratio) was performed in the same manner, the structures of the complexes differ significantly. The complex 1, {[Cu2(L1)Cl2]2[CuCl4]}·2MeCN·2H2O, consists of [Cu2(L1)Cl2]+ units in which Cu(II) ions are bridged by the HL1 ligand oxygen and each of these Cu(II) ions is connected with Cu(II) ions of the next dimeric unit via two bridging Cl− ions to form a chain structure. In the dinuclear [Cu2(L2)Cl3]⋅0.5MeCN complex 2, each Cu(II) is asymmetrically bridged by the ligand oxygen and chloride anions, whereas the remaining chloride anions are apically bound to Cu(II) cations. In contrast to the complex 1, the square-pyramidal geometry of the both Cu(II) centers is strongly distorted. The magnetic study revealed that antiferromagnetic interactions in the complex 2 are much stronger than in the complex 1, which was corresponded with magneto-structural examination. Thin layers of the studied Cu(II) complexes were deposited on Si(111) by the spin coating method and studied by scanning electron microscopy (SEM/EDS), atomic force microscopy (AFM), and fluorescence spectroscopy. The Cu(II) complexes and their thin layers exhibited fluorescence between 489–509 nm and 460–464 nm for the compounds and the layers, respectively. Additionally, DFT calculations were performed to explain the structures and electronic spectral properties of the ligands.

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