scholarly journals An optimal designed experiment for the alkaline hydrolysis of feather keratin

2021 ◽  
Author(s):  
Małgorzata Dąbrowska ◽  
Agata Sommer ◽  
Izabela Sinkiewicz ◽  
Antoni Taraszkiewicz ◽  
Hanna Staroszczyk
Keyword(s):  
Molecular Weight ◽  
Alkaline Hydrolysis ◽  
Volume Ratio ◽  
Hydrolysis Time ◽  
Process Yield ◽  
Feather Keratin ◽  
Wide Ph Range ◽  
Designed Experiment ◽  
Input Variables ◽  
Hydrolysis Of

AbstractFeathers, burdensome waste from the poultry industry, can be a cheap source of keratin, a protein with excellent physicochemical, biological, and mechanical properties. Acid and alkaline hydrolyses are usually adopted for isolation of keratin from its natural resources. This study aimed at assessing the statistically significant effect of input variables in the alkaline hydrolysis of keratin from chicken feathers on the process yield and on the molecular weight of peptides obtained. The effect of the volume ratio of 1M NaOH to the feathers’ mass, the hydrolysis time, and the shaking speed of the reaction mixture on the process yield were analyzed. The use of statistical analysis at the design step of experiment allowed reducing the trial number from 27 to 9. Among the input variables analyzed, only the volume ratio of 1M NaOH to the feathers’ mass had a significant effect on the process yield, while none of them significantly affected the molecular weight of the peptides obtained. All hydrolysates were dominated by two peptides’ fractions, with molecular weights of ca. 130 and 250 kDa, and mixture of many peptides of weight close to 10 kDa and smaller. Alkaline hydrolysis of feather keratin yielded protein hydrolysates soluble over a wide pH range.

scholarly journals An Optimal Designed Experiment for the Alkaline Hydrolysis of Feather Keratin

2021 ◽  
Author(s):  
Małgorzata Dąbrowska ◽  
Agata Sommer ◽  
Izabela Sinkiewicz ◽  
Antoni Taraszkiewicz ◽  
Hanna Staroszczyk
Keyword(s):  
Molecular Weight ◽  
Alkaline Hydrolysis ◽  
Volume Ratio ◽  
High Yield ◽  
Hydrolysis Time ◽  
Process Yield ◽  
Feather Keratin ◽  
Wide Ph Range ◽  
Input Variables ◽  
Hydrolysis Of

Abstract Feathers, burdensome waste from the poultry industry, can be a cheap source of keratin, a protein with excellent physicochemical, biological and mechanical properties. The high yield of the keratin isolation is ensured by alkaline hydrolysis. This study aimed at assessing the statistically significant effect of input variables in the alkaline hydrolysis of keratin from chicken feathers on the process yield and on the molecular weight of peptides obtained. The volume ratio of 1M NaOH to the feathers mass, the hydrolysis time and the shaking speed of the reaction mixture were analyzed. The use of statistical analysis at the design step of experiment allowed to reduce of the trials number from 27 to 9. Among the input variables analyzed, only the volume ratio of 1M NaOH to the feathers mass had a significant effect on the process yield, while none of them significantly affected the molecular weight of the peptides obtained. All hydrolysates were dominated by two peptides fractions, with molecular weights of ca. 130 and 250 kDa, and mixture of many peptides of weight close to 10 kDa and smaller. Alkaline hydrolysis of feather keratin yielded protein hydrolysates soluble over a wide pH range.

Effects of Molecular Weight of Poly(ethylene glycol) on the Thermal Properties and the Alkaline Hydrolysis of Copolyesters

2012 ◽  
Vol 49 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Young-June Kim ◽  
Min-Ho Jee ◽  
Eun-Hee Lee ◽  
Jin-Uk Choi ◽  
Dong-Hyun Noh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Ethylene Glycol ◽  
Alkaline Hydrolysis ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Hydrolysis Of

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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