scholarly journals Structural studies of a mannitol teichoic acid from the cell wall of bacterium N.C.T.C. 9742

1985 ◽  
Vol 226 (2) ◽  
pp. 587-599 ◽  
Author(s):  
W J Anderton ◽  
S G Wilkinson
Keyword(s):  
Cell Wall ◽  
Hydroxy Group ◽  
Alkaline Hydrolysis ◽  
Teichoic Acid ◽  
Paper Electrophoresis ◽  
Spectroscopic Studies ◽  
Exchange Chromatography ◽  
Brevibacterium Linens ◽  
Brevibacterium Epidermis ◽  
Hydrolysis Of

Degradative and n.m.r.-spectroscopic studies have been carried out on a novel mannitol teichoic acid extracted from the cell wall of bacterium N.C.T.C. 9742, for which the name Brevibacterium iodinum has been proposed. The backbone of the polymer is a poly(D-mannitol phosphate) containing 1--6 phosphodiester linkages. In most residues, pyruvic acid is acetal-linked to positions 4 and 5 of the mannitol. About half of the mannitol residues carry a beta-D-glucopyranosyl substituent at position 2. The glucosylmannitol was isolated and thoroughly characterized. At least 24 products were detected by ion-exchange chromatography and paper electrophoresis after alkaline hydrolysis of the polymer. Not all of these products could be identified. The main mechanistic pathways for depolymerization by the cleavage of phosphodiester linkages during alkaline hydrolysis involved (a) participation by the 2-hydroxy group and a cyclic phosphodiester intermediate (leading to a series of mannitol-based products) and (b) participation by the 3-hydroxy group in the cyclization of mannitol (leading to a series of products based on 1,4-anhydromannitol). The presence of glycerol phosphates in hydrolysates could be ascribed either to a linkage unit or to a separate glycerol teichoic acid. The mannitol teichoic acid was absent from the cell walls of Brevibacterium linens and Brevibacterium epidermis (one strain of each was examined).

scholarly journals Ion-exchange chromatography of a dinucleotide preparation from controlled alkaline hydrolysis of ribonucleic acids

1969 ◽  
Vol 114 (2) ◽  
pp. 271-277 ◽  
Author(s):  
Kimihiko Satoh ◽  
Yasuo Inoue
Keyword(s):  
Alkaline Hydrolysis ◽  
Exchange Chromatography ◽  
Reaction Conditions ◽  
Time Saving ◽  
Ribonucleic Acids ◽  
Alkaline Hydrolysate ◽  
Chromatographic Procedure ◽  
Acidic Conditions ◽  
Hydrolysis Of ◽  
Dowex 1

With the aim of preparing the 16 possible ribodinucleotides derived from the four principal ribonucleotides, we made a kinetic study to determine the optimum conditions for a partial alkaline hydrolysis of RNA. Satisfactory results were obtained when the hydrolysis of RNA (1g.) in 0·2m-sodium hydroxide (100ml.) at 37° was ceased approx. 10min. after the start of the reaction. The relative yields of the monomer, dimer and trimer fractions were approx. 41:30:15 in E260 units, indicating that the reaction conditions were reasonably close to those required from kinetic considerations. The partial alkaline hydrolysate was chromatographed on a column of DEAE-Sephadex A-25 in the presence of 7m-urea. The dinucleotide fraction thus obtained was subjected to a subsequent chromatography on Dowex 1 (X2) under acidic conditions to separate the mixture according to base composition and base sequence. The results were satisfactory, and most of the 32 dinucleotides [i.e. 16 XpYp(3′) plus 16 XpYp(2′)] were fractionated by this single chromatographic procedure. The present method should be useful for further study of oligonucleotides as a time-saving method for the simultaneous preparation of a variety of dinucleotides. Further, examination of the present chromatographic pattern has provided several empirical criteria useful for the identification of oligonucleotides other than dimers appearing in the elution profile of Dowex 1 (X2) column chromatography under similar conditions.

Allopregnanolone Derivatives: Synthesis of 3α-Hydroxy-7a-homo-5α-pregnan-20-one

2000 ◽  
Vol 65 (7) ◽  
pp. 1156-1162 ◽  
Author(s):  
Hana Chodounská ◽  
Alexander Kasal
Keyword(s):  
Hydroxy Group ◽  
Alkaline Hydrolysis ◽  
Protecting Group ◽  
Hydrolysis Of

3α-Hydroxy-7a-homo-5α-pregnan-20-one and 3α-hydroxy-7a-homo-5α-pregnane-7,20-dione were prepared from (20R)-3α-(methoxymethoxy)-7-oxo-5α-pregnan-20-yl benzoate. Homo- logation of the B ring was carried out by the Demyanov rearrangement of the corresponding cyanohydrin. Alkaline hydrolysis of the protecting group and oxidation of the formed 20-hydroxy group and deprotection of the 3-hydroxy group were performed either with (20R)-3α-(methoxymethoxy)-7-oxo-7a-homo-5α-pregnan-20-ol derivative or with the product of the Huang Minlon deoxygenation at carbon 7.

QUALITATIVE ANALYSES OF VEGETATIVE CELL WALLS AND SPORE WALLS OF SOME REPRESENTATIVE SPECIES OF STREPTOMYCES

1966 ◽  
Vol 12 (5) ◽  
pp. 985-994 ◽  
Author(s):  
Peter J. DeJong ◽  
Elizabeth McCoy
Keyword(s):  
Cell Wall ◽  
Aspartic Acid ◽  
Vegetative Cell ◽  
Cell Walls ◽  
Teichoic Acid ◽  
Minor Component ◽  
Paper Electrophoresis ◽  
Diaminopimelic Acid ◽  
Streptomyces Species ◽  
Spore Walls

Vegetative cell walls and spore walls of seven Streptomyces species representing four types of spore morphology were qualitatively analysed for their components. Amino acid and carbohydrate components (glucose, glucosamine, muramic acid, diaminopimelic acid, glutamic acid, glycine, alanine, arginine, threonine, valine, leucine, and aspartic acid) in both types of walls were identical in all species. Aspartic acid was a major component in spore walls, but a minor component in vegetative cell walls. Although organic phosphate was present in both vegetative- and spore-wall hydrolysates, the other components of teichoic acid were not found nor was teichoic acid extracted from the isolated walls by cold trichloroacetic acid. A portion of the vegetative cell wall was rendered soluble with lysozyme and separated by paper electrophoresis into two fractions detected with ninhydrin. The lysozyme-resistant portion of the vegetative cell wall showed the same major and minor components as the spore walls, which are also lysozyme resistant.

Influence of medium on alkaline hydrolysis of succinic acid monomethyl and monopropyl esters

1980 ◽  
Vol 45 (11) ◽  
pp. 2873-2882
Author(s):  
Vladislav Holba ◽  
Ján Benko
Keyword(s):  
Succinic Acid ◽  
Kinetic Parameters ◽  
Alkaline Hydrolysis ◽  
Specific Interactions ◽  
Nonaqueous Media ◽  
The Media ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.

Synthesis of Normuramic Acid Carba Analog and Its Glycopeptide Derivative Resistant to β-Elimination Splitting of the Side Chain

2000 ◽  
Vol 65 (11) ◽  
pp. 1726-1736 ◽  
Author(s):  
Miroslav Ledvina ◽  
Radka Pavelová ◽  
Anna Rohlenová ◽  
Jan Ježek ◽  
David Šaman
Keyword(s):  
Ethyl Ester ◽  
Alkaline Hydrolysis ◽  
Benzyl Ester ◽  
Side Chain ◽  
Propanoic Acid ◽  
Hydrolysis Of

Carba analogs of normuramic acid, i.e., 3-(benzyl 2-acetamido-2,3-dideoxy-4,6-O-isopropylidene-α-D-glucopyranosid-3-yl)propanoic acid derivatives (nitrile or esters) 3a-3c were prepared by addition of radicals generated from benzyl 2-acetamido-2-deoxy-4,6-O-isopropylidene-3-O-[(methylsulfanyl)thiocarbonyl]- (2a) or -3-O-(phenoxythiocarbonyl)-α-D-glucopyranoside (2b) with Bu3SnH to acrylonitrile or acryl esters. Alkaline hydrolysis of ethyl ester 3c afforded 3-(benzyl 2-acetamido-2,3-dideoxy-4,6-O-isopropylidene-α-D-glucopyranosid-3-yl)propanoic acid (5). Coupling of acid 5 with L-2-aminobutanoyl-D-isoglutamine benzyl ester trifluoroacetate and subsequent deprotection of the intermediate 6 furnished N-[3-(2-acetamido-2,3-dideoxy-α-D-glucopyranosid-3-yl)propanoyl]-L-2-aminobutanoyl-D-isoglutamine (7).

Kinetic study of hydrolysis of benzoates. part xxvii. ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous Bu4NBr

2009 ◽  
Vol 74 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Signe Vahur ◽  
Oksana Travnikova ◽  
Ilmar A. Koppel
Keyword(s):  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Pure Water ◽  
Substituent Effects ◽  
Benzoic Acids ◽  
Resonance Effects ◽  
The Media ◽  
Substituted Benzoic Acids ◽  
Hydrolysis Of ◽  
Ortho Substituent

The second-order rate constants k (in dm3 mol–1 s–1) for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, have been measured spectrophotometrically in aqueous 0.5 and 2.25 M Bu4NBr at 25 °C. The substituent effects for para and meta derivatives were described using the Hammett relationship. For the ortho derivatives the Charton equation was used. For ortho-substituted esters two steric scales were involved: the EsB and the Charton steric (υ) constants. When going from pure water to aqueous 0.5 and 2.25 M Bu4NBr, the meta and para polar effects, the ortho inductive and resonance effects in alkaline hydrolysis of phenyl esters of substituted benzoic acids, became stronger nearly to the same extent as found for alkaline hydrolysis of C6H5CO2C6H4-X. The steric term of ortho-substituted esters was almost independent of the media considered. The rate constants of alkaline hydrolysis of ortho-, meta- and para-substituted phenyl benzoates (X-C6H4CO2C6H5, C6H5CO2C6H4-X) and alkyl benzoates, C6H5CO2R, in water, 0.5 and 2.25 M Bu4NBr were correlated with the corresponding IR stretching frequencies of carbonyl group, (ΔνCO)X.

Kinetic Study of Hydrolysis of Benzoates. Part XXVI. Variation of the Substituent Effect with Solvent in Alkaline Hydrolysis of Substituted Alkyl Benzoates

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1557-1570 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Ilmar A. Koppel
Keyword(s):  
Kinetic Study ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Substituent Effect ◽  
Substituent Effects ◽  
Alkyl Substituent ◽  
Solvent Parameters ◽  
Substituent Constants ◽  
Hydrolysis Of ◽  
Main Factor

The second-order rate constants k2 (dm3 mol-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates C6H5CO2R have been measured spectrophotometrically in aqueous 0.5 M Bu4NBr at 50 and 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3, CH2CH3) and in aqueous 5.3 M NaClO4 at 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH). The dependence of the alkyl substituent effects on different solvent parameters was studied using the following equations:      ∆ log k = c0 + c1σI + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆EσI + c7∆YσI + c8∆PσI     ∆ log k = c0 + c1σ* + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆Eσ* + c7∆Yσ* + c8∆Pσ* .  ∆ log k = log kR - log kCH3. σI and σ* are the Taft inductive and polar substituent constants. E, Y and P are the solvent electrophilicity, polarity and polarizability parameters, respectively. In the data treatment ∆E = ES - EH2O , ∆Y = YS - YH2O , ∆P = PS - PH2O were used. The solvent electrophilicity, E, was found to be the main factor responsible for changes in alkyl substituent effects with medium. When σI constants were used, variation of the polar term of alkyl substituents with the solvent electrophilicity E was found to be similar to that observed earlier for meta and para substituents, but twice less when σ* constants were used. The steric term for alkyl substituents was approximately independent of the solvent parameters.

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