丁酸

丁酸
Skeletal structure	Flat structure
	IUPAC名; 丁酸; Butyric acid
別名	butyric acid; propanecarboxylic acid butanoic acid
識別
CAS號	107-92-6
PubChem	264
ChemSpider	259
SMILES	O=C(O)CCC;
InChI	1/C4H8O2/c1-2-3-4(5)6/h2-3H2,1H3,(H,5,6);
InChIKey	FERIUCNNQQJTOY-UHFFFAOYAP
UN編號	2820
ChEBI	30772
DrugBank	DB03568
KEGG	C00246
MeSH	Butyric+acid
IUPHAR配體	1059
性質
化學式	C4H8O2
摩爾質量	88.1051 g·mol⁻¹
外觀	無色液體
密度	0.96 g/mL
熔點	-7.9 °C (265.1 K)
沸點	163.5 °C (436.5 K)
溶解性（水）	混溶
pKa	4.82
折光度n; D	1.3980 (19 °C)
黏度	0.1529 cP
危險性
	歐盟危險性符號; 有害 Xn 腐蝕性 C
警示術語	R：R20 R21 R22 R34 R36 R37 R38
MSDS	External MSDS
閃點	72 °C（162 °F）
自燃溫度	452 °C（846 °F）
相關物質
相關羧酸	丙酸; 丙烯酸; 丁二酸; 2-羥基丁二酸; 酒石酸; 2-丁烯酸; 反-丁烯二酸; 戊酸
相關化學品	1-丁醇; 丁醛; 丁酸甲酯
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

丁酸，又稱酪酸，是化學式為C H₃CH₂CH₂-COOH的羧酸和短鏈飽和脂肪酸，存在於腐臭的黃油、帕馬森乾酪、嘔吐物和腋臭中。丁酸帶有難聞的氣味，味先辣後甜，與乙醚類似。10ppb濃度的丁酸即可被狗嗅出，人則大於10ppm。

丁酸是脂肪酸，在動物脂肪和植物油中以丁酸酯形式存在。其甘油酯占黃油的3~4%，當黃油腐爛後，含有難聞氣味的丁酸即通過水解釋放出來。它是短鏈脂肪酸的主要一員。丁酸為弱酸，酸度與乙酸（pK_a=4.76）類似，pK_a為4.82。^[1]該相似性與它們共有的-CH₂COOH末端結構有關。^[2]丁酸密度0.96 g/cm³，摩爾質量88.1051。

丁酸室溫下為無色油狀液體，-8°C凝固，164°C沸騰。可溶於水、乙醇和乙醚，其水溶液中加入氯化鈣會沉澱出丁酸。丁酸被重鉻酸鉀和硫酸氧化得到二氧化碳和乙酸，被鹼性高錳酸鉀氧化則得到二氧化碳。丁酸鈣（Ca(C₄H₇O₂)₂·H₂O）的溶解度隨溫度升高而降低。

丁酸的結構異構體為異丁酸，2-甲基丙酸。

生產

工業

在工業中，丁酸是透過丙烯和合成氣加氫甲酰化生產、形成丁醛，丁醛被氧化成最終產物。^[3]

H
2 + CO + CH
3CH=CH
2 → CH
3CH
2CH
2CHOoxidation→butyric acid

然而，以這種方式獲得的丁酸不能被視為天然產物，因此不用於食品工業中。

發酵

生產天然丁酸的方式為發酵，丁酸可以透過特殊厭氧細菌進行發酵後產生，能產生丁酸的細菌包含梭菌屬、丁酸桿菌屬、丁酸弧菌屬、梭桿菌屬...等厭氧微生物，基於商業目的，又以梭菌屬為最適合的物種，常見的菌種為丁酸梭菌（酪酸菌）^[4]。

在其他常見的益生菌中，以梭菌屬所生產的丁酸量最多、嗜酸乳桿菌能產生少量丁酸，雙歧桿菌則不會產生丁酸。^[5]

用途

丁酸在食品、飲料行業應用十分廣泛、也可以作為純酸用於乳製品工業。

丁酸甲酯、丁酸乙酯 (增味劑)：丁酸以酯的形式作為食品添加劑以增加水果香味。^[6]
丁酸鈉(補充劑)：丁酸也會製成口服補充劑，多以丁酸鈉的形式出現，有研究指出，補充丁酸會改變發炎性腸道疾病患者的腸道微生物群。^[7]

生理效應

丁酸在能量代謝（及糖尿病、肥胖）、炎症反應和免疫反應中有許多作用。丁酸可以被線粒體代謝產生ATP，也可以通過組蛋白修飾酶和G蛋白偶聯受體（ FFAR2、FFAR3、HCA2等）產生生理效應。^[8]^[9]

成癮性

丁酸是I類組蛋白脫乙酰酶選擇性拮抗劑。^[10]組蛋白脫乙酰酶作為組蛋白修飾酶，可以抑制基因表達。組蛋白脫乙酰酶可以調節突觸形成、突觸可塑性，調節長期記憶的形成。I類組蛋白脫乙酰酶已知參與了成癮性的形成。^[11]^[12]^[13] 丁酸和其他組蛋白脫乙酰酶拮抗劑被用於研究在藥物成癮實驗動物中組蛋白脫乙酰酶的基因轉錄、神經和行為學效應。^[13]^[14]^[15]

參考資料

^ Adimix Sodium Butanoate information (PDF). [2008-05-10]. （原始內容 (PDF)存檔於2008-05-27）.
^ Using the pKa table. [2008-05-10]. （原始內容存檔於2009-02-08）.
^ Wiley-VCH (編). Ullmann's Encyclopedia of Industrial Chemistry. Carboxylic Acids, Aliphatic 1. Wiley. 2003-03-11 [2024-03-27]. ISBN 978-3-527-30385-4. doi:10.1002/14356007.a05_235. （原始內容存檔於2018-03-05）（英語）.
^ Zigová, Jana; Šturdı́k, Ernest; Vandák, Dušan; Schlosser, Štefan. Butyric acid production by Clostridium butyricum with integrated extraction and pertraction. Process Biochemistry. 1999-10, 34 (8) [2024-03-27]. doi:10.1016/S0032-9592(99)00007-2. （原始內容存檔於2023-03-14）（英語）.
^ Markowiak-Kopeć, Paulina; Śliżewska, Katarzyna. The Effect of Probiotics on the Production of Short-Chain Fatty Acids by Human Intestinal Microbiome. Nutrients. 2020-04-16, 12 (4) [2024-04-12]. ISSN 2072-6643. PMC 7230973 . PMID 32316181. doi:10.3390/nu12041107. （原始內容存檔於2024-04-15）（英語）.
^ He, Guo-qing; Kong, Qing; Chen, Qi-he; Ruan, Hui. Batch and fed-batch production of butyric acid by Clostridium butyricum ZJUCB. Journal of Zhejiang University-SCIENCE B. 2005-11, 6 (11). ISSN 1673-1581. PMC 1390654 . PMID 16252341. doi:10.1631/jzus.2005.B1076 （英語）.
^ Facchin, Sonia; Vitulo, Nicola; Calgaro, Matteo; Buda, Andrea; Romualdi, Chiara; Pohl, Daniel; Perini, Barbara; Lorenzon, Greta; Marinelli, Carla; D』Incà, Renata; Sturniolo, Giacomo Carlo. Microbiota changes induced by microencapsulated sodium butyrate in patients with inflammatory bowel disease. Neurogastroenterology & Motility. 2020-10, 32 (10). ISSN 1350-1925. PMC 7583468 . PMID 32476236. doi:10.1111/nmo.13914 （英語）.
^ Kasubuchi M, Hasegawa S, Hiramatsu T, Ichimura A, Kimura I. Dietary gut microbial metabolites, short-chain fatty acids, and host metabolic regulation. Nutrients. 2015, 7 (4): 2839–49. PMC 4425176 . PMID 25875123. doi:10.3390/nu7042839 . Short-chain fatty acids (SCFAs) such as acetate, butyrate, and propionate, which are produced by gut microbial fermentation of dietary fiber, are recognized as essential host energy sources and act as signal transduction molecules via G-protein coupled receptors (FFAR2, FFAR3, OLFR78, GPR109A) and as epigenetic regulators of gene expression by the inhibition of histone deacetylase (HDAC). Recent evidence suggests that dietary fiber and the gut microbial-derived SCFAs exert multiple beneficial effects on the host energy metabolism not only by improving the intestinal environment, but also by directly affecting various host peripheral tissues.
^ Tilg H, Moschen AR. Microbiota and diabetes: an evolving relationship. Gut. September 2014, 63 (9): 1513–1521. PMID 24833634. S2CID 22633025. doi:10.1136/gutjnl-2014-306928.
^ Offermanns S, Colletti SL, Lovenberg TW, Semple G, Wise A, IJzerman AP. International Union of Basic and Clinical Pharmacology. LXXXII: Nomenclature and Classification of Hydroxy-carboxylic Acid Receptors (GPR81, GPR109A, and GPR109B). Pharmacological Reviews. June 2011, 63 (2): 269–90. PMID 21454438. doi:10.1124/pr.110.003301 .
^ Robison AJ, Nestler EJ. Transcriptional and epigenetic mechanisms of addiction. Nat. Rev. Neurosci. November 2011, 12 (11): 623–637. PMC 3272277 . PMID 21989194. doi:10.1038/nrn3111.
^ Nestler EJ. Epigenetic mechanisms of drug addiction. Neuropharmacology. January 2014,. 76 Pt B: 259–268. PMC 3766384 . PMID 23643695. doi:10.1016/j.neuropharm.2013.04.004.
^ ^13.0 ^13.1 Walker DM, Cates HM, Heller EA, Nestler EJ. Regulation of chromatin states by drugs of abuse. Curr. Opin. Neurobiol. February 2015, 30: 112–121. PMC 4293340 . PMID 25486626. doi:10.1016/j.conb.2014.11.002.
^ Ajonijebu DC, Abboussi O, Russell VA, Mabandla MV, Daniels WM. Epigenetics: a link between addiction and social environment. Cellular and Molecular Life Sciences. August 2017, 74 (15): 2735–2747. PMC 11107568 . PMID 28255755. S2CID 40791780. doi:10.1007/s00018-017-2493-1.
^ Legastelois R, Jeanblanc J, Vilpoux C, Bourguet E, Naassila M. Mécanismes épigénétiques et troubles de l'usage d'alcool : une cible thérapeutique intéressante? [Epigenetic mechanisms and alcohol use disorders: a potential therapeutic target]. Biologie Aujourd'hui. 2017, 211 (1): 83–91. PMID 28682229. doi:10.1051/jbio/2017014  （法語）.

外部連結

國際化學品安全卡1334

[1] Adimix Sodium Butanoate information (PDF). [2008-05-10]. （原始內容 (PDF)存檔於2008-05-27）.

[2] Using the pKa table. [2008-05-10]. （原始內容存檔於2009-02-08）.

[3] Wiley-VCH (編). Ullmann's Encyclopedia of Industrial Chemistry. Carboxylic Acids, Aliphatic 1. Wiley. 2003-03-11 [2024-03-27]. ISBN 978-3-527-30385-4. doi:10.1002/14356007.a05_235. （原始內容存檔於2018-03-05）（英語）.

[4] Zigová, Jana; Šturdı́k, Ernest; Vandák, Dušan; Schlosser, Štefan. Butyric acid production by Clostridium butyricum with integrated extraction and pertraction. Process Biochemistry. 1999-10, 34 (8) [2024-03-27]. doi:10.1016/S0032-9592(99)00007-2. （原始內容存檔於2023-03-14）（英語）.

[5] Markowiak-Kopeć, Paulina; Śliżewska, Katarzyna. The Effect of Probiotics on the Production of Short-Chain Fatty Acids by Human Intestinal Microbiome. Nutrients. 2020-04-16, 12 (4) [2024-04-12]. ISSN 2072-6643. PMC 7230973 . PMID 32316181. doi:10.3390/nu12041107. （原始內容存檔於2024-04-15）（英語）.

[6] He, Guo-qing; Kong, Qing; Chen, Qi-he; Ruan, Hui. Batch and fed-batch production of butyric acid by Clostridium butyricum ZJUCB. Journal of Zhejiang University-SCIENCE B. 2005-11, 6 (11). ISSN 1673-1581. PMC 1390654 . PMID 16252341. doi:10.1631/jzus.2005.B1076 （英語）.

[7] Facchin, Sonia; Vitulo, Nicola; Calgaro, Matteo; Buda, Andrea; Romualdi, Chiara; Pohl, Daniel; Perini, Barbara; Lorenzon, Greta; Marinelli, Carla; D』Incà, Renata; Sturniolo, Giacomo Carlo. Microbiota changes induced by microencapsulated sodium butyrate in patients with inflammatory bowel disease. Neurogastroenterology & Motility. 2020-10, 32 (10). ISSN 1350-1925. PMC 7583468 . PMID 32476236. doi:10.1111/nmo.13914 （英語）.

[Review_–_General_summary_as_of_April_2015-8] Kasubuchi M, Hasegawa S, Hiramatsu T, Ichimura A, Kimura I. Dietary gut microbial metabolites, short-chain fatty acids, and host metabolic regulation. Nutrients. 2015, 7 (4): 2839–49. PMC 4425176 . PMID 25875123. doi:10.3390/nu7042839 . Short-chain fatty acids (SCFAs) such as acetate, butyrate, and propionate, which are produced by gut microbial fermentation of dietary fiber, are recognized as essential host energy sources and act as signal transduction molecules via G-protein coupled receptors (FFAR2, FFAR3, OLFR78, GPR109A) and as epigenetic regulators of gene expression by the inhibition of histone deacetylase (HDAC). Recent evidence suggests that dietary fiber and the gut microbial-derived SCFAs exert multiple beneficial effects on the host energy metabolism not only by improving the intestinal environment, but also by directly affecting various host peripheral tissues.

[Review_for_diabetes-9] Tilg H, Moschen AR. Microbiota and diabetes: an evolving relationship. Gut. September 2014, 63 (9): 1513–1521. PMID 24833634. S2CID 22633025. doi:10.1136/gutjnl-2014-306928.

[IUPHAR's_comprehensive_2011_review_on_HCARs-10] Offermanns S, Colletti SL, Lovenberg TW, Semple G, Wise A, IJzerman AP. International Union of Basic and Clinical Pharmacology. LXXXII: Nomenclature and Classification of Hydroxy-carboxylic Acid Receptors (GPR81, GPR109A, and GPR109B). Pharmacological Reviews. June 2011, 63 (2): 269–90. PMID 21454438. doi:10.1124/pr.110.003301 .

[Nestler-11] Robison AJ, Nestler EJ. Transcriptional and epigenetic mechanisms of addiction. Nat. Rev. Neurosci. November 2011, 12 (11): 623–637. PMC 3272277 . PMID 21989194. doi:10.1038/nrn3111.

[Nestler_2014_epigenetics-12] Nestler EJ. Epigenetic mechanisms of drug addiction. Neuropharmacology. January 2014,. 76 Pt B: 259–268. PMC 3766384 . PMID 23643695. doi:10.1016/j.neuropharm.2013.04.004.

[Chromatin_states-13] 13.0 ^13.1 Walker DM, Cates HM, Heller EA, Nestler EJ. Regulation of chromatin states by drugs of abuse. Curr. Opin. Neurobiol. February 2015, 30: 112–121. PMC 4293340 . PMID 25486626. doi:10.1016/j.conb.2014.11.002.

[pmid28255755-14] Ajonijebu DC, Abboussi O, Russell VA, Mabandla MV, Daniels WM. Epigenetics: a link between addiction and social environment. Cellular and Molecular Life Sciences. August 2017, 74 (15): 2735–2747. PMC 11107568 . PMID 28255755. S2CID 40791780. doi:10.1007/s00018-017-2493-1.

[pmid28682229-15] Legastelois R, Jeanblanc J, Vilpoux C, Bourguet E, Naassila M. Mécanismes épigénétiques et troubles de l'usage d'alcool : une cible thérapeutique intéressante? [Epigenetic mechanisms and alcohol use disorders: a potential therapeutic target]. Biologie Aujourd'hui. 2017, 211 (1): 83–91. PMID 28682229. doi:10.1051/jbio/2017014  （法語）.

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