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Isobutyric acid, also known as 2-methylpropanoic acid, is a carboxylic acid with structural formula (CH₃)₂-CH-COOH.

It is found in the free state in carobs (Ceratonia siliqua), in vanilla and in the root of Arnica dulcis, and as an ethyl ester in croton oil.

Isobutyric acid is an isomer of n-butyric acid; they have the same chemical formula C₄H₈ O₂ but a different structure.

Production

Isobutyric acid may be artificially prepared by the hydrolysis of isobutyronitrile with alkalis, by the oxidation of isobutanol with potassium dichromate and sulfuric acid,^[3] or by the action of sodium amalgam on methacrylic acid. Isobutyric acid is a liquid under common conditions with a somewhat unpleasant smell. It boils at 155 °C and has a specific gravity is 0.9697 (0 °C). When heated with a chromic acid solution to 140 °C, it decomposes to form carbon dioxide and acetone. Alkaline potassium permanganate oxidizes it to α-hydroxyisobutyric acid, (CH₃)₂-C(OH)-COOH. Its salts are more soluble in water than those of butyric acid.

Biological production

Isobutyric acid can also be manufactured commercially using engineered bacteria using a sugar feedstock.^[4]

Isobutyric acid is a retained trivial name under the IUPAC rules.^[5]

References

^ Merck Index, 11th Edition, 5039
^ Bjerrum, J., et al. Stability Constants, Chemical Society, London, 1958.
^ I. Pierre and E. Puchot (1873). "New Studies on Valerianic Acid and its Preparation on a Large Scale". Ann. de chim. et de phys. 28: 366.
^ "Biological pathways to produce methacrylate".
^ Panico, R.; Powell, W. H.; Richer, J. C., eds. (1993). "Recommendation R-9.1". A Guide to IUPAC Nomenclature of Organic Compounds. IUPAC/Blackwell Science. ISBN 0-632-03488-2.

This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.

English Journal

Stability of the maternal gut microbiota during late pregnancy and early lactation.

Jost T1, Lacroix C, Braegger C, Chassard C.Author information 1Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland, ted.jost@hest.ethz.ch.AbstractScarce research has been performed to assess whether the human maternal gut microbiota undergoes changes during the perinatal period. Therefore, in the present study, gut microbiota composition of seven healthy mothers(to-be) was assessed at different time points during the perinatal period (i.e. weeks 3-7 prepartum and days 3-6, 9-14, and 25-30 postpartum) using quantitative polymerase chain reaction (qPCR) and pyrosequencing, and was complemented by short-chain fatty acids (SCFA) and calprotectin quantification using high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. qPCR revealed the predominance of members of the Firmicutes, Bacteroides, and Bifidobacterium without detectable changes over the perinatal period. Pyrosequencing supported these data in terms of microbiota stability for any population at any taxonomic level, although ratios of members of the Actinobacteria and Bacteroidetes differed between the two methods. However, the number of operational taxonomic units observed by pyrosequencing was subjected to fluctuations and the relative abundance of Streptococcus decreased numerically postpartum (P = 0.11), which may indicate that aberrancies in subdominant populations occur perinatally. Furthermore, total fecal SCFA concentrations, particularly the branched-chain fatty acids isobutyrate and isovalerate, were higher than for non-pregnant subjects throughout the perinatal period. This suggests metabolic changes and increased energy extraction via proteolytic, in addition to saccharolytic fermentation, accompanied by low-grade inflammation based on fecal calprotectin levels. Our data show that the maternal gut microbiota remained stable over the perinatal period despite altered metabolic activity and low-grade inflammation; however, it remains to be confirmed whether changes preceded earlier during pregnancy and succeeded later postpartum.
Current microbiology.Curr Microbiol.2014 Apr;68(4):419-27. doi: 10.1007/s00284-013-0491-6. Epub 2013 Nov 21.
Scarce research has been performed to assess whether the human maternal gut microbiota undergoes changes during the perinatal period. Therefore, in the present study, gut microbiota composition of seven healthy mothers(to-be) was assessed at different time points during the perinatal period (i.e. we
PMID 24258611

Effects of incremental amounts of fish oil on trans fatty acids and Butyrivibrio bacteria in continuous culture fermenters.

Abughazaleh AA1, Ishlak A.Author information 1Department of Animal Science, Food and Nutrition, Southern Illinois University, Carbondale, IL, USA.AbstractPrevious studies have shown that adding fish oil (FO) to ruminant animal diets increased vaccenic acid (VA; t11 C18:1) accumulation in the rumen. Therefore, the objective of this study was to evaluate the effect of dietary FO amounts on selected strains of rumen bacteria involved in biohydrogenation. A single-flow continuous culture system consisting of four fermenters was used in a 4 × 4 Latin square design with four 9 days consecutive periods. Treatment diets were as follows: (i) control diet (53:47 forage to concentrate; CON), (ii) control plus FO at 0.5% (DM basis; FOL), (iii) control plus FO at 2% (DM basis; FOM) and (iv) control plus FO at 3.5% (DM basis; FOH). Fermenters were fed treatment diets three times daily at 120 g/day. Samples were collected from each fermenter on day 9 of each period at 1.5, 3 and 6 h post-morning feeding and then composited into one sample per fermenter. Increasing dietary FO amounts resulted in a linear decrease in acetate and isobutyrate concentrations and a linear decrease in acetate-to-propionate ratio. Propionate, butyrate, valerate and isovalerate concentrations were not affected by FO supplementation. Concentrations of C18:0 in fermenters linearly decreased, while concentrations of t10 C18:1 and VA linearly increased as dietary FO amounts increased. The concentrations of c9t11 and t10c12 conjugated linoleic acid were not affected by FO supplementation. The DNA abundance for Butyrivibrio fibrisolvens, Butyrivibrio vaccenic acid subgroup, Butyrivibrio stearic acid subgroup and Butyrivibrio proteoclasticus linearly decreased as dietary FO amounts increased. In conclusion, FO effects on trans fatty acid accumulation in the rumen may be explained in part by FO influence on Butyrivibrio group.
Journal of animal physiology and animal nutrition.J Anim Physiol Anim Nutr (Berl).2014 Apr;98(2):271-8. doi: 10.1111/jpn.12077. Epub 2013 Apr 15.
Previous studies have shown that adding fish oil (FO) to ruminant animal diets increased vaccenic acid (VA; t11 C18:1) accumulation in the rumen. Therefore, the objective of this study was to evaluate the effect of dietary FO amounts on selected strains of rumen bacteria involved in biohydrogenation
PMID 23581938

Expanding ester biosynthesis in Escherichia coli.

Rodriguez GM1, Tashiro Y1, Atsumi S2.Author information 11] Department of Chemistry, University of California-Davis, Davis, California, USA. [2].2Department of Chemistry, University of California-Davis, Davis, California, USA.AbstractTo expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l-1). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters.
Nature chemical biology.Nat Chem Biol.2014 Mar 9. doi: 10.1038/nchembio.1476. [Epub ahead of print]
To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to f
PMID 24609358

Japanese Journal

Aggregation Pheromone Secretion Change of Riptortus pedestris (Hemiptera: Alydidae) Depending on Diet

Shin Hyo Seob,Ryu Tae Hee,Kwon Hye Ri,Seo Mi Ja,Yu Yong Man,Aoki Chisa,Yasunaga Chisa,Youn Young Nam
Journal of the Faculty of Agriculture, Kyushu University 60(2), 357-362, 2015-09-18
… We focused on tetradecyl isobutyrate (TI) which is a known insect attractant. …
NAID 120005661369

褐色腐朽菌オオウズラタケが放散する揮発性有機化合物の分析手法の検討

小沼ルミ,水越厚史,瓦田研介 [他],吉田誠
木材保存 41(3), 108-118, 2015
… これらのうちの７種の主要化合物（methyl isobutyrate，2,5-dimethylfuran，1-octene，methyl tiglate，methyl 2-furoate，3-octanone，および methyl benzoate）をPTR-MS法により分析した結果，それぞれのMVOCは，その種類によって放散パターンが異なることが明らかとなった。 …
NAID 130005085984

Anaerocella delicata gen. nov., sp. nov., a strictly anaerobic bacterium in the phylum Bacteroidetes isolated from a methanogenic reactor of cattle farms

Abe Kunihiro,Ueki Atsuko,Ohtaki Yoshimi,Kaku Nobuo,Watanabe Kazuya,Ueki Katsuji
The Journal of General and Applied Microbiology 58(6), 405-412, 2012
… Strain WN081T produced small amounts of acetate, propionate, isobutyrate, butyrate, isovalerate and H2 from PYV liquid medium. …
NAID 130004802231

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★リンクテーブル★

リンク元	「イソ酪酸」「イソ酪酸塩」「isobutyric acid」

「イソ酪酸」

Isobutyric acid
	IUPAC name 2-Methylpropanoic acid
	Other names Isobutyric acid; 2-Methylpropionic acid; Isobutanoic acid
Identifiers
CAS number	79-31-2
ChemSpider	6341
UNII	8LL210O1U0
DrugBank	DB02531
KEGG	C02632
ChEBI	CHEBI:16135
ChEMBL	CHEMBL108778
Jmol-3D images	Image 1
	SMILES O=C(O)C(C)C ;
	InChI InChI=1S/C4H8O2/c1-3(2)4(5)6/h3H,1-2H3,(H,5,6) ; Key: KQNPFQTWMSNSAP-UHFFFAOYSA-N InChI=1/C4H8O2/c1-3(2)4(5)6/h3H,1-2H3,(H,5,6); Key: KQNPFQTWMSNSAP-UHFFFAOYAB ;
Properties
Molecular formula	C4H8O2
Molar mass	88.11 g/mol
Density	0.9697 g/cm3 at 0 °C
Melting point	−47 °C (−53 °F; 226 K)
Boiling point	155 °C (311 °F; 428 K)
Acidity (pKa)	4.86
	Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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	Infobox references