Meconic acid, also known as acidum meconicum and poppy acid, is a

chemical substance A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be com ...

found in certain plants of the poppy family,

Papaveraceae The Papaveraceae, informally known as the poppy family, are an economically important family (biology), family of about 42 genera and approximately 775 known species of flowering plants in the order Ranunculales. The family is cosmopolitan dis ...

, such as ''

Papaver somniferum ''Papaver somniferum'', commonly known as the opium poppy or breadseed poppy, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which both opium and poppy seeds are derived and is also a valuable orname ...

'' (opium poppy) and '' Papaver bracteatum''. Meconic acid constitutes about 5% of

opium Opium (also known as poppy tears, or Lachryma papaveris) is the dried latex obtained from the seed Capsule (fruit), capsules of the opium poppy ''Papaver somniferum''. Approximately 12 percent of opium is made up of the analgesic alkaloid mor ...

and can be used as an analytical marker for the presence of opium. Meconic acid has erroneously been described as a mild

narcotic The term narcotic (, from ancient Greek ναρκῶ ''narkō'', "I make numb") originally referred medically to any psychoactive compound with numbing or paralyzing properties. In the United States, it has since become associated with opiates ...

, but it has little or no physiological activity, and is not used medicinally. Meconic acid forms

salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

with

alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ...

s and

metal A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...

s. These salts as well as meconic acid

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s are called meconates. Meconic acid was first isolated by

Friedrich Sertürner Friedrich Wilhelm Adam Sertürner (; 19 June 1783 – 20 February 1841) was a German pharmacist and a pioneer of alkaloid chemistry. He is best known for his discovery of morphine, which he isolated from opium in 1804, and for conducting tests, ...

in 1805.Friedrich Sertürner (1805
(Untitled letter to the editor)
''Journal der Pharmacie für Aerzte, Apotheker und Chemisten'' (Journal of Pharmacy for Physicians, Apothecaries, and Chemists), 13 : 229–243. See also: Sertuerner (1817
"Ueber das Morphium, eine neue salzfähige Grundlage, und die Mekonsäure, als Hauptbestandtheile des Opiums"
(On morphine, a new salifiable .e., precipitable fundamental substance, and meconic acid, as principal components of opium), ''Annalen der Physik'', 55 : 56–89.

Chemistry

Meconic acid is a

dicarboxylic acid In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl groups (). The general molecular formula for dicarboxylic acids can be written as , where R can be aliphatic or aromatic.Boy Cornils, Peter Lappe "Dicarbox ...

. Its structure contains two

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl ...

groups (-COOH) and one keto group (=O) attached to a

pyran In chemistry, pyran is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the location ...

ring. Meconic acid gives a red color with

ferric chloride Iron(III) chloride describes the inorganic compounds with the formula (H2O)x. Also called ferric chloride, these compounds are some of the most important and commonplace compounds of iron. They are available both in anhydrous and in hydrated f ...

. Meconic acid is colorless and is only slightly soluble in water but readily soluble in alcohol.

References

* {{Components of opium Dicarboxylic acids 4-Pyrones Enols