Perkin communications. Cationic water-soluble calixarenes: new host molecules which catalyse basic hydrolysis of a phosphate ester

1. The hydrolysis of added 32P-labelled phospholipids by whole ram and bull semen and the separated spermatozoal and plasma components was examined. 2. The ethanolamine phosphoglycerides were rapidly attacked by washed spermatozoa, forming predominantly glycerylphosphorylethanolamine, but with whole semen and seminal plasma a lysophosphatidylethanolamine was also detected. 3. The hydrolysis of lecithin by spermatozoa and plasma was very slow, and glycerylphosphorylcholine was the sole product detected. 4. Ram testicular spermatozoa were comparatively inactive in metabolizing both phospholipids, but ampulla contents showed the same activity as ejaculated semen. 5. Phosphatidylinositol was metabolized by spermatozoa obtained from any portion of the ram reproductive tract and also by seminal plasma. With testicular components, ampulla contents and washed ejaculated spermatozoa, inositol monophosphate, an unidentified phosphate ester and inorganic phosphate were the main products. In contrast, with whole semen and seminal plasma, glycerylphosphorylinositol was the predominant water-soluble phosphate ester. 6. Accessory-gland secretion obtained from vasectomized rams showed a pronounced phospholipase A activity towards ethanolamine phosphoglyceride. 7. On aerobic incubation of whole ram semen there was a decrease in the concentration of all phospholipid classes, although cardiolipin showed the greatest percentage decrease. In the choline phosphoglyceride fraction, this loss was confined to the plasmalogen component. This breakdown of phospholipids was decreased considerably when the spermatozoa were washed, and was not observed when whole bull semen was incubated under similar conditions.

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The structure of a glycerylphosphoryldiglucosyl diglyceride from the lipids of Acholeplasma laidlawii strain B

Biochemical Journal ◽

10.1042/bj1290167 ◽

1972 ◽

Vol 129 (1) ◽

pp. 167-173 ◽

Cited By ~ 28

Author(s):

N. Shaw ◽

P. F. Smith ◽

H. M. Verheij

Keyword(s):

Periodate Oxidation ◽

Water Soluble ◽

Hydroxyl Group ◽

Phosphate Ester ◽

Soluble Phosphate ◽

Acholeplasma Laidlawii ◽

New Type ◽

Bacterial Lipid ◽

Hydrolysis Of ◽

Phospholipases A

1. The phosphatidylglucose structure proposed previously (Smith & Henrikson, 1965) for the glucose-containing phospholipid from Acholeplasma laidlawii is incorrect. 2. The structure now proposed is 3-(sn-glycerol-3-phosphoryl-6′-[O-α-d-glucopyranosyl-(1&2)-O-α-d-glucopyranosyl])- sn-1,2-diglyceride, a new type of bacterial lipid. 3. Deacylation of the lipid gave a single water-soluble phosphate ester which could be distinguished on chromatography from synthetic samples of glucosylphosphorylglycerols. 4. Hydrolysis of the lipid with alkali gave a mixture of fatty acids, glycerol 2-phosphate, sn-glycerol 3-phosphate and O-α-d-glucopyranosyl-(1&2)-O-α- d-glucopyranosyl-(1&1)-d-glycerol. 5. The lipid was unaffected on incubation with phospholipases A, C and D. 6. Diglucosyl diglyceride was isolated after treatment of the lipid with 60% HF, establishing the location of the fatty acid residues. 7. Periodate oxidation studies showed that the sn-glycerol 3-phosphate was esterified to the 6-hydroxyl group of one of the glucose residues in diglucosyl diglyceride.

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Basic hydrolysis of carbamate to amine in aqueous ethanol

ChemSpider Synthetic Pages ◽

10.1039/sp734 ◽

2014 ◽

Author(s):

John MacMillan

Keyword(s):

Aqueous Ethanol ◽

Basic Hydrolysis ◽

Hydrolysis Of

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A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i1.845 ◽

2015 ◽

Vol 12 (1) ◽

pp. 3910-3918 ◽

Cited By ~ 1

Author(s):

Dr Remon M Zaki ◽

Prof Adel M. Kamal El-Dean ◽

Dr Nermin A Marzouk ◽

Prof Jehan A Micky ◽

Mrs Rasha H Ahmed

Keyword(s):

Biological Activity ◽

Carbonyl Compounds ◽

Mass Spectra ◽

The Other ◽

Pyridine Derivatives ◽

Facile Synthesis ◽

High Biological Activity ◽

Basic Hydrolysis ◽

Pyridine Carboxylate ◽

Hydrolysis Of

Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

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Kinetics and Mechanistic Study of Hydrolysis of Adenosine Monophosphate Disodium Salt (AMPNa2) in Acidic and Alkaline Media

Open Chemistry ◽

10.1515/chem-2019-0044 ◽

2019 ◽

Vol 17 (1) ◽

pp. 544-556

Author(s):

Yoke-Leng Sim ◽

Beljit Kaur

Keyword(s):

Rate Constant ◽

Adenosine Monophosphate ◽

Disodium Salt ◽

Second Order ◽

Information Storage ◽

Alkaline Media ◽

Basic Medium ◽

Mechanistic Study ◽

Phosphate Ester ◽

Hydrolysis Of

AbstractPhosphate ester hydrolysis is essential in signal transduction, energy storage and production, information storage and DNA repair. In this investigation, hydrolysis of adenosine monophosphate disodium salt (AMPNa2) was carried out in acidic, neutral and alkaline conditions of pH ranging between 0.30-12.71 at 60°C. The reaction was monitored spectrophotometrically. The rate ranged between (1.20 ± 0.10) × 10-7 s-1 to (4.44 ± 0.05) × 10-6 s-1 at [NaOH] from 0.0008 M to 1.00M recorded a second-order base-catalyzed rate constant, kOH as 4.32 × 10-6 M-1 s-1. In acidic conditions, the rate ranged between (1.32 ± 0.06) × 10-7 s-1 to (1.67 ± 0.10) × 10-6 s-1 at [HCl] from 0.01 M to 1.00 M. Second-order acid-catalyzed rate constant, kH obtained was 1.62 × 10-6 M-1 s-1. Rate of reaction for neutral region, k0 was obtained from graphical method to be 10-7 s-1. Mechanisms were proposed to involve P-O bond cleavage in basic medium while competition between P-O bond and N-glycosidic cleavage was observed in acidic medium. In conclusion, this study has provided comprehensive information on the kinetic parameters and mechanism of cleavage of AMPNa2 which mimicked natural AMP cleavage and the action of enzymes that facilitate its cleavage.

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Optimizing Chitin Depolymerization by Lysozyme to Long-Chain Oligosaccharides

Marine Drugs ◽

10.3390/md19060320 ◽

2021 ◽

Vol 19 (6) ◽

pp. 320

Author(s):

Arnaud Masselin ◽

Antoine Rousseau ◽

Stéphanie Pradeau ◽

Laure Fort ◽

Rodolphe Gueret ◽

...

Keyword(s):

Time Course ◽

Water Soluble ◽

Organic Fertilizers ◽

Symbiotic Associations ◽

Egg White Lysozyme ◽

Hen Egg White ◽

Ecological Transition ◽

Optimized Conditions ◽

Hydrolysis Of ◽

Long Chain

Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.

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