1-プロペン-1,2,3-トリカルボン酸

化学的特性Aconitic acid has pleasant, winey, acid taste; almost odorless. Aconitic acid of the trans-configuration can be isolated during the processing of sugarcane by precipitating it as the calcium salt from cane syrup or molasses. The concentration in molasses ranges from 1.8 to 2.5%. Aconitic acid may be synthesized from citric acid by dehydration with sulfuric acid or by catalytic dehydration. The cis-configuration is somewhat unstable and is readily rearranged to the trans form by heating. Trans-aconitic acid is decarboxylated to itaconic acid by heating to 180°F. The cis form occurs in plant and animal tissues as a metabolic intermediate in the Krebs cycle during the isomerization of citric acid to isocitric acid by the action of enzyme aconitase

解説C6H6O6(174.11)．2-カルボキシグルタコン酸に相当するトリカルボン酸．通常，カルボキシル基がトランス形のものである．キンポウゲ科トリカブトAconitum，トクサ，サトウキビ，テンサイなどに含まれており，トランス形から無水物を経て不安定なシス形にかえることができる．クエン酸を硫酸で脱水すると得られるが，糖みつからも得られる．"葉片状の結晶．融点194～195 ℃(分解)．pKa1 2.8，pKa2 4.66(25 ℃)．エタノールに易溶，エーテルに不溶．融点まで加熱すると無水イタコン酸になり，また水と180 ℃ にまで加熱するとイタコン酸と二酸化炭素を生じる．cis-アコニット酸は融点125 ℃．加熱すると容易にトランス形にかわる．ゴムや樹脂の可塑剤に用いられる．[CAS 499-12-7]森北出版「化学辞典（第2版）

用途香料・香辛料、製造用剤

天然物の起源Reported found in beet root, sugarcane, the leaves and tubers of Aconitum napellus, and other natural products (Pelargonium species).

使用Aconitic Acid is a flavoring substance which occurs in the leaves and tubers of aconitum napellus l. And other ranunculaceae. Transaconitic acid can be isolated during sugar cane processing, by precipitation as the calcium salt from cane sugar or molasses. It may be synthesized by sulfuric acid dehydration of citric acid but not by the methanesulfonic acid method. It is used in a maximum level, as served, of 0.003% for baked goods, 0.002% for alcoholic beverages, 0.0015% for frozen dairy products, 0.0035% for soft candy, and 0.0005% or less for all other food categories.

製造方法By dehydration of citric acid with concentrated H2SO4: Aconitic acid prepared by this or other methods has the transconfiguration; the cis-isomer is little known. Trans-aconitic acid can be isolated during sugarcane processing by precipitation as the calcium salt from cane sugar or molasses.