**History and Occurrence of Butyric Acid:**
– Discovered in 1814 by Michel Eugène Chevreul.
– Named in 1817, with detailed properties presented in 1823.
– Derived from the Greek word for butter.
– Found in butter, animal fat, plant oils, bovine milk, breast milk, and cheese.
– Detected by dogs at 10 parts per billion.
– Used in food manufacturing as a flavoring agent.
– Acts as an endogenous agonist of human hydroxycarboxylic acid receptor2.
**Production and Reactions of Butyric Acid:**
– Industrial production from propene and syngas.
– Separated from aqueous solutions using salts like calcium chloride.
– Microbial biosynthesis by anaerobic bacteria.
– Reacts as a typical carboxylic acid.
– Forms various derivatives like amides, esters, anhydrides, and chlorides.
– Utilized in the production of various butyrate esters.
**Uses and Pharmacokinetics of Butyric Acid:**
– Used in the preparation of butyrate esters.
– Produces cellulose acetate butyrate (CAB) for tools, paints, coatings.
– Acts as an HDAC inhibitor.
– Metabolized by human XM-ligases into butyryl-CoA.
– Essential energy source for colon cells.
– Metabolized in mitochondria for ATP generation.
– Absorbed and metabolized by colonocytes and the liver.
**Biological Effects and Health Implications of Butyric Acid:**
– Modulates histone-modifying enzymes and G-protein coupled receptors.
– Has antimicrobial and anticarcinogenic effects.
– Essential for immune homeostasis in the gut.
– Promotes regulatory T cell differentiation.
– Protects the intestinal epithelial barrier and inhibits inflammation.
– Impacts energy homeostasis, inflammation, and immune function in humans.
**Butyric Acid in Disease Prevention and Potential Treatments:**
– Implications for colon cancer prevention and treatment.
– Butyrate depletion can impact the pathogenesis of vasculitic conditions.
– Fecal microbiota transplants can replenish butyrate levels effectively.
– Butyrate administration via oral supplements or enemas terminates inflammation symptoms.
– Healthy levels of butyrate in the gut are crucial for immune system health.
– Butyrate has implications for immune function, mood, and behavior.
Butyric acid (/ˈbjuːtɪrɪk/; from Ancient Greek: βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula CH3CH2CH2CO2H. It is an oily, colorless liquid with an unpleasant odor. Isobutyric acid (2-methylpropanoic acid) is an isomer. Salts and esters of butyric acid are known as butyrates or butanoates. The acid does not occur widely in nature, but its esters are widespread. It is a common industrial chemical and an important component in the mammalian gut.
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| Names | |||
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| Preferred IUPAC name
Butanoic acid | |||
| Other names | |||
| Identifiers | |||
3D model (JSmol)
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| ChEBI |
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| ChEMBL |
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| ChemSpider | |||
| DrugBank |
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| ECHA InfoCard | 100.003.212 | ||
| EC Number |
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| KEGG |
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| MeSH | Butyric+acid | ||
PubChem CID
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| RTECS number |
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| UNII |
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| UN number | 2820 | ||
CompTox Dashboard (EPA)
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| Properties | |||
| C 3H 7COOH | |||
| Molar mass | 88.106 g·mol−1 | ||
| Appearance | Colorless liquid | ||
| Odor | Unpleasant, similar to vomit or body odor | ||
| Density | 1.135 g/cm3 (−43 °C) 0.9528 g/cm3 (25 °C) | ||
| Melting point | −5.1 °C (22.8 °F; 268.0 K) | ||
| Boiling point | 163.75 °C (326.75 °F; 436.90 K) | ||
| Sublimes at −35 °C ΔsublH | |||
| Miscible | |||
| Solubility | Miscible with ethanol, ether. Slightly soluble in CCl4 | ||
| log P | 0.79 | ||
| Vapor pressure | 0.112 kPa (20 °C) 0.74 kPa (50 °C) 9.62 kPa (100 °C) | ||
Henry's law
constant (kH) |
5.35·10−4 L·atm/mol | ||
| Acidity (pKa) | 4.82 | ||
| −55.10·10−6 cm3/mol | |||
| Thermal conductivity | 1.46·105 W/m·K | ||
Refractive index (nD)
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1.398 (20 °C) | ||
| Viscosity | 1.814 cP (15 °C) 1.426 cP (25 °C) | ||
| Structure | |||
| Monoclinic (−43 °C) | |||
| C2/m | |||
a = 8.01 Å, b = 6.82 Å, c = 10.14 Å α = 90°, β = 111.45°, γ = 90°
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| 0.93 D (20 °C) | |||
| Thermochemistry | |||
Heat capacity (C)
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178.6 J/mol·K | ||
Std molar
entropy (S⦵298) |
222.2 J/mol·K | ||
Std enthalpy of
formation (ΔfH⦵298) |
−533.9 kJ/mol | ||
Std enthalpy of
combustion (ΔcH⦵298) |
2183.5 kJ/mol | ||
| Hazards | |||
| GHS labelling: | |||
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| Danger | |||
| H314 | |||
| P280, P305+P351+P338, P310 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | 71 to 72 °C (160 to 162 °F; 344 to 345 K) | ||
| 440 °C (824 °F; 713 K) | |||
| Explosive limits | 2.2–13.4% | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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2000 mg/kg (oral, rat) | ||
| Safety data sheet (SDS) | External MSDS | ||
| Related compounds | |||
Related carboxylic acids
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Propionic acid, Pentanoic acid | ||
Related compounds
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1-Butanol Butyraldehyde Methyl butyrate | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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