プロピオン酸

外観

無色～ほとんど無色透明液体

性質

1. 名称
和名：プロピオン酸
英名：propionic acid
IUPAC名：propanoic acid

2. 分子式
C3H6O2

3. 分子量
74.08

4. 融点
-20.83℃

5. 溶媒溶解性
水、エタノール、、エーテルに易溶

定義

本品は、次の化学式で表される脂肪酸である。

解説

propanoic acid．C3H6O2(74.08)．C2H5COOH．乳製品に含まれ，生体内では糖質からピルビン酸，スクシニルCoAを経て合成される．プロピオンアルデヒドの酸化，プロピオノニトリルの加水分解，あるいはレッペ反応を利用して，エテン，一酸化炭素および水蒸気から得られる．刺激臭をもつ無色の液体．融点－21.5 ℃，沸点141.1 ℃，65.8 ℃(5.3 kPa)．"0.99336．"1.3848．Ka 1.22×10－5(25 ℃)．水，アルコール類，エーテル，クロロホルムなどに可溶．食品添加物，農薬，医薬，香料，合成原料に用いられる．[CAS 79-09-4]
森北出版「化学辞典（第2版）

用途

プロピオン酸は，飽和脂肪酸の一つ。プロピオニトリル（プロパンニトリル）を加水分解するか、1-プロパノール（プロピルアルコール）を酸化すると得られる。水とよく混じり合うが、ギ酸や酢酸と異なり、塩析すると油状物として分離する。エタノール（エチルアルコール）、エーテルと任意の割合で混じり合う。エステル化剤として有機合成に用いられるほか、カルシウム塩、ナトリウム塩はカビ防止剤として用いられる。反芻(はんすう)動物は、第一胃中での細菌発酵により、セルロース・糖質をプロピオン酸に変えてエネルギー源としている。エステル化の試薬として，果実香料の合成などに用いられるほか，ナトリウム塩はカビによる皮膚疾患の治療薬となる。

用途

有機合成原料、食品保存料

用途

防カビ剤、果実フレーバー、 香水原料

構造

プロピオン酸は、分子式C3H6O2、分子量74.08 g/molの有機化合物で、直鎖状カルボン酸の一種です。

プロピオン酸は、常温常圧下で無色透明な液体であり、特有の酸っぱい臭いを持ちます。水には可溶ですが、油や有機溶媒には不溶です。

プロピオン酸は比較的安定な化合物であり、酸化、還元、熱分解などの反応性は比較的高くありません。しかし、プロピオン酸は強い酸化剤と反応すると引火性を示します。また、高濃度の蒸気は刺激性を示すため、取り扱いには注意が必要です。

化粧品の成分用途

pH調整剤、防腐剤、忌避剤.殺虫剤、殺菌剤、香料

効能

抗菌薬, 酸性化剤

説明

First described by Johann Gottlieb in 1844, propanoic acid has become one of the most widely used additives in processed foods for human consumption and animal feedstocks. Originally, Gottlieb found the compound among the degradation products of certain sugars. The term – propionic acid – itself has the unique distinction of once being the designation for all fatty acids due to the writings of Jean-Baptiste Dumas, who, in 1847, postulated that all fatty acids were in reality just one compound. While larger chain fatty acids are important components of all living things, propionic acid is the shortest fatty acid that exhibits the classic behaviors of similar compounds.

化学的特性

Propionic acid, CH3CH2COOH, also known as propanoic acid and methylacetic acid, is a clear, colorless liquid that boils at 140°C (284 OF). It is flammable. It has a pungent odor and is soluble in water and alcohol. The Odor Threshold is 0.16 ppm. Propionic acid is an aliphatic monocarboxylic acid. Propionic acid is used in nickel electroplating solutions,perfumes, artificial flavors, pharmaceuticals, and manufacturing propionates.

天然物の起源

Reported found in apple, apple juice, banana, currants, pineapple, raspberry, papaya, onion, sauerkraut, tomato, vinegar, beef, beef broth, beer, blackberry juice, bread, cheese, cherry juice, butter, yogurt, milk, cream, lean and fatty fish, cured pork, cooked beef and mutton, chicken fat, cognac, rum, whiskies, cider, sherry, roasted cocoa bean, cocoa powder, coffee, black currant juice, white currant juice, grape juice, grape musts and port wine, grapefruit juice, grape syrup, orange juice, Valencia orange oil, orange essence, roasted peanuts, pecans, potato chips, honey, soybean, Arctic bramble, coconut meat, cloudberry, mushroom, sesame seed, cardamom, rice, jackfruit, sake, buckwheat, laurel, peated malt, cassava, Bourbon vanilla, oyster, mussels, scallop, Chinese quince and maté.

使用

Propionic Acid is the acid source of the propionates. propionic acid in the liquid form has a strong odor and is corrosive, so it is used as the sodium, calcium, and potassium salts as a preservative. these yield the free acid in the ph range of the food in which they are used. it functions principally against mold. see calcium propionate; sodium propionate.

定義

ChEBI: Propionic acid is a short-chain saturated fatty acid comprising ethane attached to the carbon of a carboxy group. It has a role as an antifungal drug. It is a short-chain fatty acid and a saturated fatty acid. It is a conjugate acid of a propionate.

調製方法

Propionic acid can be obtained from wood pulp waste liquor by fermentation. It can also be prepared from ethylene, carbon monoxide and steam; from ethanol and carbon monoxide using boron trifluoride catalyst; from natural gas; or as a by-product in the pyrolysis of wood. Very pure propionic acid can be obtained from propionitrile. Propionic acid can be found in dairy products in small amounts.

一般的な説明

Propionic acid is a clear oily aqueous liquid with a pungent rancid odor. Burns skin and the vapors irritate mucous membranes. Corrosive to most metals and tissue. Density 8.3 lb / gal.

空気と水の反応

Dilution with water causes release of heat.

反応プロフィール

Propionic acid reacts as an acid to neutralize bases in exothermic reactions. Burns when exposed to heat, flame or oxidizers. When heated to decomposition emits acrid smoke and irritating fumes [Lewis, 3rd ed., 1993, p. 1090].

危険性

Moderate fire risk. Strong eye, skin and upper respiratory tract irritant.

健康ハザード

Propionic acid is a toxic and corrosive liquid. Contact with the eyes can result ineye injury. Skin contact may cause burns.Acute exposures to its vapors can causeeye redness, mild to moderate skin burns,and mild coughing (ACGIH 1986). Ingestionof high amounts of this acid may producecorrosion of the mouth and gastrointestinaltract in humans. Other symptoms includevomiting, diarrhea, ulceration, and convulsions. Oral LD50 value in rats is about3500–4300 mg/kg. The LD50 value by skinabsorption in rabbits is 500 mg/kg..

火災危険

Flammable/combustible material. May be ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.

使用用途

プロピオン酸はカルボン酸の一種で、無色で油状の液体です。化学式はCH3CH2COOHで表されます。

プロピオン酸は、医薬品、除草剤、香料、樹脂など、さまざまな産業用途に使用されています。
また、カビや細菌の増殖を抑制する作用を持つため、保存料としても一般的に使用されています。

応用例（製薬）

Propionic acid is primarily used as an antioxidant and antimicrobial preservative in foods, and in oral and topical pharmaceutical applications. It is also used as an esterifying agent.

臨床応用

Propionic acid is an antifungal agent that is nonirritatingand nontoxic. After application, it is present in perspiration in low concentration ( 0.01%). Salt forms with sodium,potassium, calcium, and ammonium are also fungicidal.Propionic acid is a clear, corrosive liquid with a characteristicodor. It is soluble in water and alcohol. Thesalts are usually used because they are nonvolatile andodorless.

安全性プロファイル

Poison by intraperitoneal route. Moderately toxic by ingestion, skin contact, and intravenous routes. A corrosive irritant to eyes, skin, and mucous membranes. Flammable liquid. Highly flammable when exposed to heat, flame, or oxidizers. To fight fire, use alcohol foam. When heated to decomposition it emits acrid smoke and irritating fumes.

安全性

Propionic acid is generally regarded as a nontoxic and nonirritant material when used in low levels as an excipient. Up to 1% may be used in food applications (up to 0.3% in flour and cheese products). Propionic acid is readily metabolized.
The pure form of propionic acid is corrosive and will cause burns to any area of contact. Both liquid and vapor forms are flammable. Concentrated propionic acid is harmful if swallowed, inhaled or absorbed through the skin. See also Sodium Propionate.
(mouse, IV): 0.63 g/kg
(rabbit, skin): 0.5 g/kg
(rat, oral): 2.6 g/kg

合成

Commercial processes produce propionic acid by chemical synthesis and in small quantities by bacterial fermentation. Industrially Propionic acid is produced by hydrocarboxylation of ethylene in presence nickel carbonyl as a catalyst.

職業ばく露

Propionic acid is used in the manufac- ture of inorganic propionates and propionate esters which are used as mold inhibitors, electroplating additives; emul- sifying agents; flavors and perfumes. It is an intermediate in pesticide manufacture, pharmaceutic manufacture; and in the production of cellulose propionate plastics. Also used as grain preservative.

発がん性

Rats fed high levels of propionic acid (4%) in a powdered diet developed forestomach neoplasia, which was believed to have arisen from sustained high levels of cellular proliferation. When administered at 4% in the diet as a pellet rather than as a powder, cellular hyperplasia and the associated severe inflammatory response were absent. In another study whereWistar ratswere fed 75%bread containing5%of the salt, sodiumpropionate rather than the acid for 1 year, no histopathology of the forestomach was reported. This suggests that the form of chemical (salt versus free acid), as well as the type of diet, is also an important factor in eliciting this effect. Harrison notes that a variety of chemicals, chemical and mechanical irritants, parasites, and dietary deficiencies cause forestomach tumors in rats. The predictive value of this finding in humans is, therefore, problematic because humans have no forestomach and food transit times are much faster. Interestingly, propionic acid inhibited the growth of the human adenocarcinoma cell line HT29 derived from similar epithelial tissue of human colon cancer patients, whereas other short-chain fatty acids, such as acetate, enhance transformation.

製造方法

プロピオン酸の製造方法

プロピオン酸が自然界に存在することは稀であり、多くは化学合成によって得られます。直接的な合成法と間接的な複製法があり、日本においては他の化合物を合成する際の副生成物として得る方法が一般的です。

そのうち、収量が多く一般的なのが、製造においてナフサを直接酸化する際に副生するプロピオン酸を回収する方法です。

直接的な合成方法としては、n -プロパノールやの酸化、プロピオノニトリルの加水分解、あるいはエテンおよびを原料とする方法がありますが、複雑な工程が必要であるため一般的ではありません。

また、一般にプロピオン酸菌と呼ばれる、Propionibacterium freudenreichiiなどの細菌を用いて炭水化物を発酵させる方法も知られています。

貯蔵

Although stable, propionic acid is flammable. It should be stored in an airtight container away from heat and flames.

輸送方法

UN1848 Propionic acid, Hazard class: 8; Labels: 8-Corrosive material. UN3463 Propionic acid, with not ＜90% acid by mass, Hazard Class 8; Labels: 8-Corrosive material, 3-Flammable liquid.

純化方法

Dry the acid with Na2SO4 or by fractional distillation, then redistil after refluxing with a few crystals of KMnO4. An alternative purification uses conversion to the ethyl ester, fractional distillation and hydrolysis. [Bradbury J Am Chem Soc 74 2709 1952.] Propionic acid can also be heated for 0.5hour with an amount of benzoic anhydride equivalent to the amount of water present (in the presence of CrO3 as catalyst), followed by fractional distillation. [Cham & Israel J Chem Soc 196 1960, Beilstein 2 IV 695.]

不和合性

Propionic acid is a medium strong acid. Incompatible with sulfuric acid, strong bases; ammonia, isocyanates, alkylene oxides; epichlorohydrin. Reacts with bases; strong oxidizers; and amines, causing fire and explo- sion hazard. Attacks many metals forming flammable/ explosive hydrogen gas. It can be salted out of aqueous solutions by the addition of calcium chloride or other salts.

廃棄物の処理

Incineration in admixture with flammable solvent.

規制状況(Regulatory Status)

GRAS listed. Accepted for use in Europe as a food additive. In Japan, propionic acid is restricted to use as a flavoring agent.