hydrolysis

The hydrolysis ( ancient Greek ὕδωρ hydor "water" and λύσις lýsis "solution, dissolution, termination") is the splitting of a (bio) chemical compound through reaction with water . In the process, a hydrogen atom is (formally) transferred to one “split piece”, the remaining hydroxy residue is bound to the other split piece. The reverse of the hydrolysis is a condensation reaction . If the solvent is also water in the reaction, hydrolysis is a solvolysis .

In general:

${\displaystyle \mathrm {{\color {Red}X{-}Y}\ +\ {\color {Blue}H{-}OH}\longrightarrow \ {\color {Red}X{-}}{\color {Blue}H}\ +\ {\color {Red}Y}{\color {Blue}{-}OH}} }$

Hydrolysis of compound XY.

Deviating from the above definition, the term hydrolysis , also known as salt hydrolysis , was used by Arrhenius to describe basic or acidic reactions that occur when salts are dissolved, the acid or base residues of which are derived from weak acids or weak bases. The hydrolysis here is a reversal of the neutralization . See Arrhenius' acid-base concept .

Examples

• Hydrolysis of alkyl fluorides
• Hydrolysis of carboxylic acid chlorides to carboxylic acids and hydrogen chloride
• Hydrolysis of benzyl chloride to benzyl alcohol and hydrogen chloride
• Hydrolysis of calcium carbide to acetylene and calcium hydroxide
• Hydrolysis of carboxamides to carboxylic acids
• Hydrolysis of carboxylic acid anhydrides to carboxylic acids
• Hydrolysis of vegetable or animal fats to glycerine and fatty acids
• Hydrolysis of a carboxylic acid ester to carboxylic acid and alcohol
• Hydrolysis of a lactone to the corresponding ω-hydroxycarboxylic acid
• Ester hydrolases catalyze the hydrolysis of one enantiomer of chiral esters to carboxylic acid and alcohol, the other enantiomer is not hydrolyzed
• Hydrolysis of acetals to aldehydes and alcohols
• Hydrolysis of ketals to ketones and alcohols
• Hydrolysis of Grignard Compounds
• Hydrolysis of isocyanides
• Hydrolysis of isothiocyanates
• Hydrolysis of nitriles via carboxamides to carboxylic acids
• Hydrolysis of oximes to carbonyl compounds (aldehydes or ketones) and hydroxylamine
• Hydrolysis of imines to carbonyl compounds ( aldehydes or ketones ) and primary amines
• Hydrolysis of hydrazones to carbonyl compounds (aldehydes or ketones) and hydrazine
• Hydrolysis of orthocarboxylic acid esters
• Hydrolysis of oxiranes
• Partial hydrolysis of peptides in which only some peptide bonds are broken
• Hydrolysis of polyurethane
• Hydrolysis of sulfonyl chlorides
• Hydrolysis of tetrachlorosilane to silicon dioxide and hydrogen chloride
• Hydrolysis of tert -butyl chloride

Most of the hydrolyses listed above run better and faster if the reaction is carried out in an acidic or basic medium instead of at neutral pH. Examples are the acid hydrolysis of esters , which is the reverse reaction to the esterification , and the saponification taking place in the base .

Enantioselective hydrolysis

Esters of chiral carboxylic acids or chiral alcohols can be hydrolyzed enantioselectively under the influence of lipases . Enantiomerically pure alcohols or enantiomerically pure carboxylic acids are formed. Similarly, racemic amides can be hydrolyzed enantioselectively in the presence of acylases . The process is used industrially for the production of the amino acid L- methionine from N -acetyl- DL- methionine.

Hydrolysis of biomolecules

Through hydrolysis, many biomolecules (e.g. proteins , disaccharides , polysaccharides or fats ) are broken down into their building blocks ( monomers ) in the metabolism , usually under catalysis by an enzyme ( hydrolase ).

An important hydrolysis reaction that gives proteins energy for mechanical work, transport processes, etc. there is the cleavage of ATP to ADP and a phosphate residue .

When analyzing the amino acid composition of proteins, purified proteins are hydrolyzed by high concentrations of hydrochloric acid in the absence of air and at temperatures> 100 ° C. By means of the hydrolyzate of the protein - with knowledge of the respective stability of the released amino acids under standard conditions and their correction factors - conclusions can be drawn about the proportion of the peptide-bound amino acid in the structure of the protein.

See also

• Ammonolysis
• Alcoholysis
• Hydrolytic class
• Collagen hydrolyzate

Individual evidence

1. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 562.
2. ^ Siegfried Hauptmann : Reaction and Mechanism in Organic Chemistry. BG Teubner, Stuttgart, 1991, p. 78, ISBN 3-519-03515-4 .
3. ↑ Entry on hydrolysis. In: Römpp Online . Georg Thieme Verlag, accessed on June 20, 2014.
4. ↑ Ivan Ernest: Binding, Structure and Reaction Mechanisms in Organic Chemistry. Springer-Verlag, 1972, p. 110, ISBN 3-211-81060-9 .
5. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 415, ISBN 3-342-00280-8 .
6. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 173, ISBN 3-342-00280-8 .
7. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 263, ISBN 3-342-00280-8 .
8. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 423, ISBN 3-342-00280-8 .
9. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 409, ISBN 3-342-00280-8 .
10. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB German publishing house for basic industry, Leipzig, 1985, p. 331 u. 739, ISBN 3-342-00280-8 .
11. ^ Hans Beyer , Wolfgang Walter : Organic chemistry. S. Hirzel Verlag, Stuttgart, 1991, 22nd edition, page 895, ISBN 3-7776-0485-2 .
12. ↑ ^{a b} Ivan Ernest: Binding, Structure and Reaction Mechanisms in Organic Chemistry , Springer-Verlag, 1972, p. 101, ISBN 3-211-81060-9 .
13. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB German publishing house for basic industry, Leipzig, 1985, p. 204, ISBN 3-342-00280-8 .
14. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 431, ISBN 3-342-00280-8 .
15. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 471, ISBN 3-342-00280-8 .
16. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 429, ISBN 3-342-00280-8 .
17. ↑ ^{a b c} Siegfried Hauptmann: Reaction and Mechanism in Organic Chemistry. BG Teubner, Stuttgart, 1991, p. 152, ISBN 3-519-03515-4 .
18. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 421, ISBN 3-342-00280-8 .
19. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 558, ISBN 3-342-00280-8 .
20. ^ Siegfried Hauptmann: Reaction and Mechanism in Organic Chemistry. BG Teubner, Stuttgart, 1991, p. 176, ISBN 3-519-03515-4 .
21. ↑ Paula Yurkanis Bruice: Organic Chemistry , Pearson Education Inc., 2004, 4th edition, p 1201, ISBN 0-13-121730-5 .
22. ↑ Hydrolysis of PU midsole , accessed on February 3, 2018.
23. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 482, ISBN 3-342-00280-8 .
24. ^ Siegfried Hauptmann: Reaction and Mechanism in Organic Chemistry. BG Teubner, Stuttgart, 1991, pp. 8-9, ISBN 3-519-03515-4 .
25. ^ Siegfried Hauptmann: Organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, pp. 418-419, ISBN 3-342-00280-8 .
26. ↑ Bernd Hoppe, Jürgen Martens : Amino acids - building blocks of life , chemistry in our time , 17th year 1983, No. 2, pp. 41–53, ISSN  0009-2851 .
27. ↑ Bernd Hoppe, Jürgen Martens: Amino acids - production and extraction , chemistry in our time , 18th year 1984, No. 3, pp. 73-86, ISSN  0009-2851 .
28. ^ Hans Beyer, Wolfgang Walter : Organic chemistry. S. Hirzel Verlag, Stuttgart, 22nd edition, 1991, pp. 894-896, ISBN 3-7776-0485-2 .