Dipeptide

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A dipeptide is an organic compound derived from two amino acids. The constituent amino acids can be the same or different. When different, two isomers of the dipeptide are possible, depending on the sequence. Several dipeptides are physiologically important, and some are both physiologically and commercially significant. A well known dipeptide is aspartame, an artificial sweetener. [1]

Contents

Glycylglycine is the simplest dipeptide. Glycylglycine.png
Glycylglycine is the simplest dipeptide.

Dipeptides are white solids. Many are far more water-soluble than the parent amino acids. [1] For example, the dipeptide Ala-Gln has the solubility of 586 g/L more than 10x the solubility of Gln (35 g/L). Dipeptides also can exhibit different stabilities, e.g. with respect to hydrolysis. Gln does not withstand sterilization procedures, whereas this dipeptide does. Because dipeptides are prone to hydrolysis, the high solubility is exploited in infusions, i.e. to provide nutrition. [2]

Examples

Aspartame is produced commercially as an artificial sweetener. Aspartame.svg
Aspartame is produced commercially as an artificial sweetener.

Commercial value

About six dipeptides are of commercial interest. [1]

Other dipeptides

Production

Synthetic dipeptides

Dipeptides are produced by coupling amino acids. The amino group on one amino acid is rendered non-nucleophilic (P in eq) and the carboxylic acid group in the second amino acid is deactivated as its methyl ester. The two modified amino acids are then combined in the presence of a coupling agent, which facilitates formation of the amide bond:

RCH(NHP)CO2H + R'CH(NH2)CO2CH3RCH(NHP)C(O)NH(CHR')CO2CH3 + H2O

Subsequent to this coupling reaction, the amine protecting group P and the ester are converted to the free amine and carboxylic acid, respectively. [3]

For many amino acids, the ancillary functional groups are protected. The condensation of the amine and the carboxylic acid to form the peptide bond generally employs coupling agents to activate the carboxylic acid. [4]

The Bergmann azlactone peptide synthesis is a classic organic synthesis for the preparation of dipeptides. [1]

Biosynthesis

Dipeptides are produced from polypeptides by the action of the hydrolase enzyme dipeptidyl peptidase. [5] Dietary proteins are digested to dipeptides and amino acids, and the dipeptides are absorbed more rapidly than the amino acids, because their uptake involves a separate mechanism. Dipeptides activate G-cells found in the stomach to secrete gastrin.

Diketopiperazines (cyclic dipeptides)

Retosiban is a cyclic dipeptide being investigated as an oral drug. Retosiban structure.svg
Retosiban is a cyclic dipeptide being investigated as an oral drug.

Diketopiperazines are a special class of dipeptides, which are cyclic. They form as side products in peptide synthesis. Many have been produced from non-canonical amino acids. [7]

Related Research Articles

<span class="mw-page-title-main">Amide</span> Organic compounds of the form RC(=O)NR′R″

In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula R−C(=O)−NR′R″, where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid with the hydroxyl group replaced by an amine group ; or, equivalently, an acyl (alkanoyl) group joined to an amine group.

<span class="mw-page-title-main">Carboxylic acid</span> Organic compound containing a –C(=O)OH group

In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is R−COOH or R−CO2H, with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.

<span class="mw-page-title-main">Ester</span> Compound derived from an acid

In chemistry, an ester is a compound derived from an acid in which the hydrogen atom (H) of at least one acidic hydroxyl group of that acid is replaced by an organyl group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well, but not according to the IUPAC.

<span class="mw-page-title-main">Ketone</span> Organic compounds of the form >C=O

In organic chemistry, a ketone is a functional group with the structure R−C(=O)−R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group −C(=O)−. The simplest ketone is acetone, with the formula (CH3)2CO. Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids, and the solvent acetone.

<span class="mw-page-title-main">Hydrazone</span> Organic compounds - Hydrazones

Hydrazones are a class of organic compounds with the structure R1R2C=N−NH2. They are related to ketones and aldehydes by the replacement of the oxygen =O with the =N−NH2 functional group. They are formed usually by the action of hydrazine on ketones or aldehydes.

<span class="mw-page-title-main">Imine</span> Organic compound or functional group containing a C=N bond

In organic chemistry, an imine is a functional group or organic compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.

In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base. An alternative name is chlorhydrate, which comes from French. An archaic alternative name is muriate, derived from hydrochloric acid's ancient name: muriatic acid.

<span class="mw-page-title-main">Acyl halide</span> Oxoacid compound with an –OH group replaced by a halogen

In organic chemistry, an acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.

Hydrolyzed protein is a solution derived from the hydrolysis of a protein into its component amino acids and peptides. While many means of achieving this exist, most common is prolonged heating with hydrochloric acid, sometimes with an enzyme such as pancreatic protease to simulate the naturally occurring hydrolytic process.

<i>N</i>,<i>N</i>-Dicyclohexylcarbodiimide Chemical compound

N,N′-Dicyclohexylcarbodiimide (DCC or DCCD) is an organic compound with the chemical formula (C6H11N)2C. It is a waxy white solid with a sweet odor. Its primary use is to couple amino acids during artificial peptide synthesis. The low melting point of this material allows it to be melted for easy handling. It is highly soluble in dichloromethane, tetrahydrofuran, acetonitrile and dimethylformamide, but insoluble in water.

<span class="mw-page-title-main">Carbodiimide</span> Class of organic compounds with general structure RN=C=NR

In organic chemistry, a carbodiimide is a functional group with the formula RN=C=NR. On Earth they are exclusively synthetic, but in interstellar space the parent compound HN=C=NH has been detected by its maser emissions.

The Bouveault–Blanc reduction is a chemical reaction in which an ester is reduced to primary alcohols using absolute ethanol and sodium metal. It was first reported by Louis Bouveault and Gustave Louis Blanc in 1903. Bouveault and Blanc demonstrated the reduction of ethyl oleate and n-butyl oleate to oleyl alcohol. Modified versions of which were subsequently refined and published in Organic Syntheses.

The Strecker amino acid synthesis, also known simply as the Strecker synthesis, is a method for the synthesis of amino acids by the reaction of an aldehyde with ammonia in the presence of potassium cyanide. The condensation reaction yields an α-aminonitrile, which is subsequently hydrolyzed to give the desired amino acid. The method is used commercially for the production of racemic methionine from methional.

Enanthic acid, also called heptanoic acid, is an organic compound composed of a seven-carbon chain terminating in a carboxylic acid functional group. It is a colorless oily liquid with an unpleasant, rancid odor. It contributes to the odor of some rancid oils. It is slightly soluble in water, but very soluble in ethanol and ether. Salts and esters of enanthic acid are called enanthates or heptanoates.

<span class="mw-page-title-main">Hell–Volhard–Zelinsky halogenation</span> Chemical reaction

The Hell–Volhard–Zelinsky halogenation reaction is a chemical transformation that involves the halogenation of a carboxylic acid at the α carbon. For this reaction to occur the α carbon must bear at least one proton. The reaction is named after the German chemists Carl Magnus von Hell (1849–1926) and Jacob Volhard (1834–1910) and the Russian chemist Nikolay Zelinsky (1861–1953).

<span class="mw-page-title-main">Erlenmeyer–Plöchl azlactone and amino-acid synthesis</span>

The Erlenmeyer–Plöchl azlactone and amino acid synthesis, named after Friedrich Gustav Carl Emil Erlenmeyer who partly discovered the reaction, is a series of chemical reactions which transform an N-acyl glycine to various other amino acids via an oxazolone.

The Schöllkopf method or Schöllkopf Bis-Lactim Amino Acid Synthesis is a method in organic chemistry for the asymmetric synthesis of chiral amino acids. The method was established in 1981 by Ulrich Schöllkopf. In it glycine is a substrate, valine a chiral auxiliary and the reaction taking place an alkylation.

<span class="mw-page-title-main">Ethyl cyanohydroxyiminoacetate</span> Chemical compound

Ethyl cyanohydroxyiminoacetate (oxyma) is the oxime of ethyl cyanoacetate and finds use as an additive for carbodiimides, such as dicyclohexylcarbodiimide (DCC) in peptide synthesis. It acts as a neutralizing reagent for the basicity or nucleophilicity of the DCC due to its pronounced acidity and suppresses base catalyzed side reactions, in particular racemization.

Glycine methyl ester hydrochloride is the organic compound with the formula [CH3O2CCH2NH3]Cl. A white, water-soluble solid, it is the hydrochloride of the methyl ester of the amino acid glycine.

<span class="mw-page-title-main">Diethyl acetamidomalonate</span> Chemical compound

Diethyl acetamidomalonate (DEAM) is a derivative of malonic acid diethyl ester. Formally, it is derived through the acetylation of ester from the unstable aminomalonic acid. DEAM serves as a starting material for racemates including both, natural and unnatural α-amino acids or hydroxycarboxylic acids. It is also usable as a precursor in pharmaceutical formulations, particularly in the cases of active ingredients like fingolimod, which is used to treat multiple sclerosis.

References

  1. 1 2 3 4 Yagasaki M, Hashimoto S (November 2008). "Synthesis and application of dipeptides; current status and perspectives". Applied Microbiology and Biotechnology. 81 (1): 13–22. doi:10.1007/s00253-008-1590-3. PMID   18795289.
  2. 1 2 Fürst P, Pogan K, Stehle P (1997). "Glutamine dipeptides in clinical nutrition". Nutrition. 13 (7–8): 731–7. doi:10.1016/S0899-9007(97)83035-3. PMID   9263278.
  3. Subirós-Funosas AE, Albericio F (2013). "Low-epimerization Peptide Bond Formation with Oxyma Pure: Preparation of Z-L-Phg-Val-OMe". Organic Syntheses. 90: 306. doi:10.15227/orgsyn.090.0306.
  4. Suppo JS, de Figueiredo RM, Campagne JM (2015). "Dipeptide Syntheses via Activated α-Aminoesters". Organic Syntheses. 92: 296–308. doi: 10.15227/orgsyn.092.0296 .
  5. Steane R. "Hydrolysis of a dipeptide". BioTopics. Retrieved 28 July 2014.
  6. Borthwick AD, Liddle J (January 2013). "Retosiban and Epelsiban: Potent and Selective Orally available Oxytocin Antagonists". In Domling A (ed.). Methods and Principles in Medicinal Chemistry: Protein-Protein Interactions in Drug Discovery. Weinheim: Wiley-VCH. pp. 225–256. ISBN   978-3-527-33107-9.
  7. Borthwick AD (July 2012). "2,5-Diketopiperazines: synthesis, reactions, medicinal chemistry, and bioactive natural products". Chemical Reviews. 112 (7): 3641–716. doi:10.1021/cr200398y. PMID   22575049.