In chemistry, a reagent (/riˈeɪdʒənt/ ree-AY-jənt) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms reactant and reagent are often used interchangeably, but reactant specifies a substance consumed in the course of a chemical reaction.Solvents, though involved in the reaction mechanism, are usually not called reactants. Similarly, catalysts are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates.
Definitions
Organic chemistry
In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents.
Analytical chemistry
In analytical chemistry, a reagent is a compound or mixture used to detect the presence or absence of another substance, e.g. by a color change, or to measure the concentration of a substance, e.g. by colorimetry. Examples include Fehling's reagent, Millon's reagent, and Tollens' reagent.
Commercial or laboratory preparations
In commercial or laboratory preparations, reagent-grade designates chemical substances meeting standards of purity that ensure the scientific precision and reliability of chemical analysis, chemical reactions or physical testing. Purity standards for reagents are set by organizations such as ASTM International or the American Chemical Society. For instance, reagent-quality water must have very low levels of impurities such as sodium and chloride ions, silica, and bacteria, as well as a very high electrical resistivity. Laboratory products which are less pure, but still useful and economical for undemanding work, may be designated as technical, practical, or crude grade to distinguish them from reagent versions.
Biology
In the field of biology, the biotechnology revolution in the 1980s grew from the development of reagents that could be used to identify and manipulate the chemical matter in and on cells. These reagents included antibodies (polyclonal and monoclonal), oligomers, all sorts of model organisms and immortalised cell lines, reagents and methods for molecular cloning and DNA replication, and many others.
Tool compounds
Tool compounds are an important class of reagent in biology. They are small molecules or biochemicals like siRNA or antibodies that are known to affect a given biomolecule[ambiguous]—for example a drug target—but are unlikely to be useful as drugs themselves, and are often starting points in the drug discovery process.
However, many natural substances are hits in almost any assay in which they are tested, and therefore not useful as tool compounds. Medicinal chemists class them instead as pan-assay interference compounds. One example is curcumin.
See also
- Limiting reagent
- Common reagents
- Product
- Reagent bottle
- Substrate
- All pages with titles containing Reagent
References
- IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (1996) "Reactant". doi:10.1351/goldbook.R05163
- Fox, Jeffrey L. (1 January 1979). "Antibody reagents revolutionizing immunology". Chemical & Engineering News Archive. 57: 15–17. doi:10.1021/cen-v057n001.p015.
- "Report of the National Institutes of Health (NIH) Working Group on Research Tools". NIH. June 4, 1998. Archived from the original on August 16, 2000.
- Ishino, S; Ishino, Y (29 August 2014). "DNA polymerases as useful reagents for biotechnology: the history of developmental research in the field". Frontiers in Microbiology. 5: 465. doi:10.3389/fmicb.2014.00465. PMC 4148896. PMID 25221550.
- Kenakin, T; Bylund, DB; Toews, ML; Mullane, K; Winquist, RJ; Williams, M (1 January 2014). "Replicated, replicable and relevant-target engagement and pharmacological experimentation in the 21st century". Biochemical Pharmacology. 87 (1): 64–77. doi:10.1016/j.bcp.2013.10.024. PMID 24269285.
- Lindsley, CW (25 September 2014). "2013 Philip S. Portoghese Medicinal Chemistry Lectureship: drug discovery targeting allosteric sites". Journal of Medicinal Chemistry. 57 (18): 7485–7498. doi:10.1021/jm5011786. PMC 4174999. PMID 25180768.
- Baker, Monya (9 January 2017). "Deceptive curcumin offers cautionary tale for chemists". Nature. 541 (7636): 144–145. Bibcode:2017Natur.541..144B. doi:10.1038/541144a. PMID 28079090.
- Dahlin, JL; Walters, MA (July 2014). "The essential roles of chemistry in high-throughput screening triage". Future Medicinal Chemistry. 6 (11): 1265–1290. doi:10.4155/fmc.14.60. PMC 4465542. PMID 25163000.
- Baell, JB; Holloway, GA (8 April 2010). "New substructure filters for removal of pan assay interference compounds (PAINS) from screening libraries and for their exclusion in bioassays". Journal of Medicinal Chemistry. 53 (7): 2719–2740. CiteSeerX 10.1.1.394.9155. doi:10.1021/jm901137j. PMID 20131845.
External links
Media related to Reagents at Wikimedia Commons
The dictionary definition of reactant at Wiktionary
In chemistry a reagent r i ˈ eɪ dʒ en t ree AY jent or analytical reagent is a substance or compound added to a system to cause a chemical reaction or test if one occurs The terms reactant and reagent are often used interchangeably but reactant specifies a substance consumed in the course of a chemical reaction Solvents though involved in the reaction mechanism are usually not called reactants Similarly catalysts are not consumed by the reaction so they are not reactants In biochemistry especially in connection with enzyme catalyzed reactions the reactants are commonly called substrates Reagents such as sulfur pictured are the starting materials used in chemical reactions DefinitionsOrganic chemistry In organic chemistry the term reagent denotes a chemical ingredient a compound or mixture typically of inorganic or small organic molecules introduced to cause the desired transformation of an organic substance Examples include the Collins reagent Fenton s reagent and Grignard reagents Analytical chemistry In analytical chemistry a reagent is a compound or mixture used to detect the presence or absence of another substance e g by a color change or to measure the concentration of a substance e g by colorimetry Examples include Fehling s reagent Millon s reagent and Tollens reagent Commercial or laboratory preparationsIn commercial or laboratory preparations reagent grade designates chemical substances meeting standards of purity that ensure the scientific precision and reliability of chemical analysis chemical reactions or physical testing Purity standards for reagents are set by organizations such as ASTM International or the American Chemical Society For instance reagent quality water must have very low levels of impurities such as sodium and chloride ions silica and bacteria as well as a very high electrical resistivity Laboratory products which are less pure but still useful and economical for undemanding work may be designated as technical practical or crude grade to distinguish them from reagent versions BiologyIn the field of biology the biotechnology revolution in the 1980s grew from the development of reagents that could be used to identify and manipulate the chemical matter in and on cells These reagents included antibodies polyclonal and monoclonal oligomers all sorts of model organisms and immortalised cell lines reagents and methods for molecular cloning and DNA replication and many others Tool compounds Tool compounds are an important class of reagent in biology They are small molecules or biochemicals like siRNA or antibodies that are known to affect a given biomolecule ambiguous for example a drug target but are unlikely to be useful as drugs themselves and are often starting points in the drug discovery process However many natural substances are hits in almost any assay in which they are tested and therefore not useful as tool compounds Medicinal chemists class them instead as pan assay interference compounds One example is curcumin See alsoLimiting reagent Common reagents Product Reagent bottle Substrate All pages with titles containing ReagentReferencesIUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 1996 Reactant doi 10 1351 goldbook R05163 Fox Jeffrey L 1 January 1979 Antibody reagents revolutionizing immunology Chemical amp Engineering News Archive 57 15 17 doi 10 1021 cen v057n001 p015 Report of the National Institutes of Health NIH Working Group on Research Tools NIH June 4 1998 Archived from the original on August 16 2000 Ishino S Ishino Y 29 August 2014 DNA polymerases as useful reagents for biotechnology the history of developmental research in the field Frontiers in Microbiology 5 465 doi 10 3389 fmicb 2014 00465 PMC 4148896 PMID 25221550 Kenakin T Bylund DB Toews ML Mullane K Winquist RJ Williams M 1 January 2014 Replicated replicable and relevant target engagement and pharmacological experimentation in the 21st century Biochemical Pharmacology 87 1 64 77 doi 10 1016 j bcp 2013 10 024 PMID 24269285 Lindsley CW 25 September 2014 2013 Philip S Portoghese Medicinal Chemistry Lectureship drug discovery targeting allosteric sites Journal of Medicinal Chemistry 57 18 7485 7498 doi 10 1021 jm5011786 PMC 4174999 PMID 25180768 Baker Monya 9 January 2017 Deceptive curcumin offers cautionary tale for chemists Nature 541 7636 144 145 Bibcode 2017Natur 541 144B doi 10 1038 541144a PMID 28079090 Dahlin JL Walters MA July 2014 The essential roles of chemistry in high throughput screening triage Future Medicinal Chemistry 6 11 1265 1290 doi 10 4155 fmc 14 60 PMC 4465542 PMID 25163000 Baell JB Holloway GA 8 April 2010 New substructure filters for removal of pan assay interference compounds PAINS from screening libraries and for their exclusion in bioassays Journal of Medicinal Chemistry 53 7 2719 2740 CiteSeerX 10 1 1 394 9155 doi 10 1021 jm901137j PMID 20131845 External linksMedia related to Reagents at Wikimedia Commons The dictionary definition of reactant at Wiktionary
