scholarly journals Metabolic studies on retinoic acid in the rat

1971 ◽  
Vol 122 (1) ◽  
pp. 1-4 ◽  
Author(s):  
P. R. Sundaresan ◽  
H. N. Bhagavan
Keyword(s):  
Retinoic Acid ◽  
Alkaline Hydrolysis ◽  
Water Soluble ◽  
Major Metabolite ◽  
Metabolic Studies ◽  
Hydrolysis Of ◽  
Soluble Fractions

The nature of metabolites in the urine arising from differentially labelled retinoic acid was investigated after injection of physiological doses into retinol-deficient rats. Distribution of radioactivity after partition of urine into ether-soluble, acidic and water-soluble fractions revealed that there were at least six metabolites in urine. Of these, the major metabolite(s) was one lacking both C-14 and C-15 of retinoic acid. Enzymic or alkaline hydrolysis of acidic and water-soluble fractions did not release any retinoic acid, thus indicating that retinoyl β-glucuronide was not present in urine in significant amounts.

Selectivity Mechanisms for Foliar Applications of Diclofop-methyl. II. Metabolism

Weed Science ◽  
1981 ◽  
Vol 29 (2) ◽  
pp. 237-241 ◽  
Author(s):  
P. F. Boldt ◽  
A. R. Putnam
Keyword(s):  
Glycine Max ◽  
Plant Extracts ◽  
Alkaline Hydrolysis ◽  
Water Soluble ◽  
Plant Residue ◽  
Panicum Miliaceum ◽  
Proso Millet ◽  
Intact Plants ◽  
Leaf Surfaces ◽  
Hydrolysis Of

The fate of foliarly applied14C diclofop-methyl {methyl 2-[4-(2,3-dichlorophenoxy)phenoxy] propanoate} was determined in intact plants of barnyardgrass [Echinochloa crus-galli(L.) Beauv.], a susceptible (S) grass; proso millet (Panicum miliaceumL.), a moderately susceptible (MS) grass; longspine sandbur [Cenchrus longispinus(Hack.) Fern.], a tolerant (T) grass; soybean [Glycine max(L.) Merr. ‘Hark’], and cucumber (Cucumis sativusL. ‘Green Star’), both T broadleaf plants, 1,3, and 5 days after treatment (DAT). Diclofop-methyl accounted for 94% of the radioactivity washed from the leaf surfaces of all species. Plant extracts contained diclofop-methyl, diclofop, and water-soluble conjugates. Barnyardgrass (S), proso millet (MS), and soybean (T) had 75, 68, and 66% of the extracted radioactivity as diclofop and diclofop-methyl. Longspine sandbur (T) and cucumber (T) had 71 and 84% of the extracted radioactivity as water-soluble conjugates. Acid hydrolysis of the water-soluble conjugates yielded 84 and 71% diclofop in barnyardgrass (S) and proso millet (MS). Cucumber (T), soybean (T), and longspine sandbur (T) had 43, 23, and 25% ring-OH diclofop. Alkaline hydrolysis of the non-extracted plant residue yielded diclofop as the major component in all species.

scholarly journals The isolation of an azobilirubin β-d-monoglucoside from dog gall-bladder bile

1974 ◽  
Vol 143 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Ellen R. Gordon ◽  
Molly Dadoun ◽  
Carl A. Goresky ◽  
Tak-Hang Chan ◽  
Arthur S. Perlin
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Gall Bladder ◽  
Alkaline Hydrolysis ◽  
Sodium Methoxide ◽  
Water Soluble ◽  
Hydrolysis Of ◽  
Conjugated Bilirubin ◽  
Nuclear Magnetic

An ethyl anthranilate azopigment of bilirubin conjugated to β-d-monoglucoside was isolated from dog gall-bladder bile. Glucose was cleaved from the azopigment by treatment with β-glucosidase and β-glucuronidase. Mild alkaline hydrolysis of the compound by sodium methoxide yielded two kinds of compounds, water-soluble and organic-soluble. The former were shown, by enzymic analysis, t.l.c., nuclear magnetic resonance, and combined g.l.c. and mass spectrometry, to contain glucose. No evidence was obtained from these data that a disaccharide was present in this fraction. The organic-soluble compounds formed during this methanolysis were shown, by t.l.c. and mass spectrometry, to be the isomeric dipyrrole azopigments of bilirubin. These findings contribute further evidence to the controversy surrounding the nature of conjugated bilirubin.

HEMICELLULOSES OF WHEAT STRAW

1951 ◽  
Vol 29 (2) ◽  
pp. 109-122 ◽  
Author(s):  
G. A. Adams ◽  
A. E. Castagne
Keyword(s):  
Wheat Straw ◽  
Potassium Hydroxide ◽  
Uronic Acid ◽  
Degree Of Polymerization ◽  
Water Soluble ◽  
Hot Water ◽  
Acid Complex ◽  
Main Fraction ◽  
Hydrolysis Of ◽  
Soluble Fractions

Various hemicellulose fractions were extracted from wheat straw holocellulose (extractive and pectin free) by successive treatments with cold and hot water, 0.5%, 1.0%, and 2.0% potassium hydroxide and were recovered by precipitation with alcohol. Approximately 25% of the holocellulose material was removed, one half being in the hot water soluble fraction. The original holocellulose, the extracted residue, and the recovered fractions were analyzed for pentosan, uronic acid anhydride, acetyl, methoxyl, and ash content. In general, the more soluble fractions had a higher uronic acid and methoxyl content; the less soluble had a higher pentosan content and a more negative rotation [Formula: see text]. Intrinsic viscosity measurements indicated that all fractions had a degree of polymerization of 25–30. Hydrolysis of the main fraction yielded D-xylose, L-arabinose, D-glucose; in addition D-galactose was found in the water soluble fractions. Quantitative determinations of the sugars in the hydrolyzates showed that D-xylose predominated, with L-arabinose, D-glucose, and D-galactose (when present) in progressively smaller amounts. On hydrolysis all fractions yielded an acid-resistant uronic acid complex that contained D-xylose and a uronic acid tentatively identified as monomethoxyl galacturonic acid.

A METHOD FOR THE IDENTIFICATION OF THE MONO-O-METHYLGLUCOSES

1953 ◽  
Vol 31 (9) ◽  
pp. 814-820 ◽  
Author(s):  
R. U. Lemieux ◽  
H. F. Bauer
Keyword(s):  
Paper Chromatography ◽  
Sodium Borohydride ◽  
Alkaline Hydrolysis ◽  
Periodate Oxidation ◽  
Methyl Cellulose ◽  
Water Soluble ◽  
The Other ◽  
Potential Value ◽  
Hydrolysis Of

Periodate oxidation of any one mono-O-methylglucopyranose and alkaline hydrolysis of the product yields a substance which can be positively distinguished by paper chromatography from the products formed under the same conditions from the other mono-O-methylglucopyranoses. Thus, the components of a mixture of the mono-O-methylglucopyranoses can be readily identified. The method appears useful for the identification of di-O-methylglucoses. Reduction with sodium borohydride prior to periodate oxidation renders the method useful for the identification of tri-O-methylglucoses. The potential value of the method, which can be used on a microscale, is illustrated by an application to the characterization of the O-methylglucoses derived from a water-soluble O-methyl-cellulose

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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