Angelic acid

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Angelic acid
Angelic acid.png
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Names
Preferred IUPAC name
(2Z)-2-Methylbut-2-enoic acid
Other names
(Z)-2-Methylbut-2-enoic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.008.441 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C5H8O2/c1-3-4(2)5(6)7/h3H,1-2H3,(H,6,7)/b4-3- Yes check.svgY
    Key: UIERETOOQGIECD-ARJAWSKDSA-N Yes check.svgY
  • C/C=C(C)\C(O)=O
  • O=C(O)\C(=C/C)C
Properties
C5H8O2
Molar mass 100.117 g·mol−1
Melting point 45.5 °C (113.9 °F; 318.6 K)
Boiling point 185 °C (365 °F; 458 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Angelic acid is a monocarboxylic unsaturated organic acid, mostly found in the plants of the family Apiaceae. It is a volatile solid with a biting taste and pungent sour odor. It is the cis isomer of 2-methyl-2-butenoic acid, which easily converts to the trans isomer, tiglic acid, upon heating or reaction with inorganic acids. The reverse transformation occurs much less readily. The salts and esters of angelic acid are called angelates. Angelic acid esters are the active components of herbal medicine used against a wide range of various health disturbances including pains, fever, gout, heartburn, etc.

Contents

Name and discovery

Angelic acid was first isolated by the German pharmacist Ludwig Andreas Buchner (1813–1897) in 1842 from the roots of the garden plant angelica ( Angelica archangelica ), which gave the acid its name. [1]

Occurrence

Angelic acid occurs in the roots of many plants, especially of the family Apiaceae. These plants include Angelica archangelica , Peucedanum ostruthium (masterwort), Levisticum officinale (lovage), [2] [3] Euryangium sumbul and Laserpitium latifolium . In the latter plant, it is present in the resin called laserpicium, and the oil of carrot also contains angelic acid. [4] Sumbul plants might contain not angelic acid itself, but a larger complex which breaks into angelic acid upon processing. [5] The acid can also be extracted from the oil of chamomile flowers, and 85% of Roman chamomile ( Anthemis nobilis ) oil consists of esters of angelic and tiglic acids; [6] [7] it also contains isobutyl angelate and amyl angelate. [8] The acid content is highest in Angelica archangelica [9] where it is about 0.3%. [2]

Properties

Angelic acid is a volatile solid with a biting taste and pungent sour odor. It crystallizes in colorless monoclinic prisms which dissolve rapidly in alcohol [10] or hot water and slowly in cold water. Angelic and tiglic acid are cis and trans isomers of 2-methyl-2-butenoic acid, respectively. The former can be entirely converted to the latter by boiling for about 40 hours, by reaction with sulfuric and other acids, [9] by heating with a base to a temperature above 100 °C, [4] or simply by storing the acid for about 25 years. [11] The reverse transformation occurs much less readily; it can be induced by ultraviolet light, but not with visible light. The conversion rate is low and only 0.36 g of angelic acid could be obtained from 13 g of tiglic acid after 43-day irradiation with a 500-watt lamp. Being the cis isomer, angelic acid has a lower melting point and higher acid dissociation constant than tiglic acid, [12] in accordance to usually observed trends. [13] [14]

Angelic acid reacts with hydrobromic acid and bromine producing bromovaleric and dibromovaleric acids, respectively, with a yield of 60–70%. Chlorovaleric and iodovaleric acids are obtained using hydrochloric and hydroiodic acids, respectively. The salts of angelic acid are called angelates. Angelates of alkaline earth metals M have a general formula M(C5H7O2)2 and form white, water-soluble crystals. [9]

Applications

The angelic acid esters of sesquiterpene alcohols, such as petasin, are the active chemical behind the strong pain-relieving and spasmolytic action of extracts from the plant butterbur. [2] Roman chamomile, in which esters of angelic and tiglic acids are the principal components, was used as a sedative and tonic, and as a medicine against nervous problems, fever, colic, heartburn, loss of appetite, gout, headache and other health disturbances. [6]

Related Research Articles

Apiaceae Family of flowering plants

Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus Apium and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,700 species in 434 genera including such well-known and economically important plants such as ajwain, angelica, anise, asafoetida, caraway, carrot, celery, chervil, coriander, cumin, dill, fennel, lovage, cow parsley, parsley, parsnip and sea holly, as well as silphium, a plant whose identity is unclear and which may be extinct.

<i>Cis</i>–<i>trans</i> isomerism pairs of molecules with the same formula but in different orientations

Cistrans isomerism, also known as geometric isomerism or configurational isomerism, is a term used in organic chemistry. The prefixes "cis" and "trans" are from Latin: "this side of" and "the other side of", respectively. In the context of chemistry, cis indicates that the functional groups (substituents) are on the same side of some plane, while trans conveys that they are on opposing sides. Cis-trans isomers are stereoisomers, that is, pairs of molecules which have the same formula but whose functional groups are in different orientations in three-dimensional space. Cis-trans notation does not always correspond to EZ isomerism, which is an absolute stereochemical description. In general, stereoisomers contain double bonds that do not rotate, or they may contain ring structures, where the rotation of bonds is restricted or prevented. Cis and trans isomers occur both in organic molecules and in inorganic coordination complexes. Cis and trans descriptors are not used for cases of conformational isomerism where the two geometric forms easily interconvert, such as most open-chain single-bonded structures; instead, the terms "syn" and "anti" are used.

Proline Chemical compound

Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group -NH
2
but is rather a secondary amine. The secondary amine nitrogen is in the protonated NH2+ form under biological conditions, while the carboxy group is in the deprotonated −COO form. The "side chain" from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it as a aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it from the non-essential amino acid L-glutamate. It is encoded by all the codons starting with CC (CCU, CCC, CCA, and CCG).

Triglyceride Any ester of glycerol having all three hydroxyl groups esterified with fatty acids

A triglyceride is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver, and are a major component of human skin oils.

Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure, or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring.

Ajwain Species of plant

Ajwain, ajowan, or Trachyspermum ammi—also known as ajowan caraway, thymol seeds, bishop's weed, or carom—is an annual herb in the family Apiaceae. Both the leaves and the seed‑like fruit of the plant are consumed by humans. The name "bishop's weed" also is a common name for other plants. The "seed" is often confused with lovage "seed".

<i>Angelica</i> Genus of flowering plants in the celery family Apiaceae

Angelica is a genus of about 60 species of tall biennial and perennial herbs in the family Apiaceae, native to temperate and subarctic regions of the Northern Hemisphere, reaching as far north as Iceland, Lapland and Greenland. They grow to 1–3 m tall, with large bipinnate leaves and large compound umbels of white or greenish-white flowers. Found mainly in China, its main use was for medicine. It shows variations in fruit anatomy, leaf morphology and subterranean structures. The genes are extremely polymorphic.

Diazomethane Simplest diazo compound and methylating agent

Diazomethane is the chemical compound CH2N2, discovered by German chemist Hans von Pechmann in 1894. It is the simplest diazo compound. In the pure form at room temperature, it is an extremely sensitive explosive yellow gas; thus, it is almost universally used as a solution in diethyl ether. The compound is a popular methylating agent in the laboratory, but it is too hazardous to be employed on an industrial scale without special precautions. Use of diazomethane has been significantly reduced by the introduction of the safer and equivalent reagent trimethylsilyldiazomethane.

Fumaric acid Organic compound

Fumaric acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297. The salts and esters are known as fumarates. Fumarate can also refer to the C
4
H
2
O2−
4
ion (in solution). Fumaric acid is the trans isomer of butenedioic acid, while maleic acid is the cis isomer.

<i>Angelica archangelica</i> Species of plant

Angelica archangelica, commonly known as garden angelica, wild celery, and Norwegian angelica, is a biennial plant from the family Apiaceae, a subspecies of which is cultivated for its sweetly scented edible stems and roots. Like several other species in Apiaceae, its appearance is similar to several poisonous species, and should not be consumed unless it has been identified with absolute certainty. Synonyms include Archangelica officinalis Hoffm. and Angelica officinalis Moench.

Cinnamic acid Chemical compound

Cinnamic acid is an organic compound with the formula C6H5CH=CHCOOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.

Caffeic acid Chemical compound

Caffeic acid is an organic compound that is classified as a hydroxycinnamic acid. This yellow solid consists of both phenolic and acrylic functional groups. It is found in all plants because it is an intermediate in the biosynthesis of lignin, one of the principal components of woody plant biomass and its residues.

Methacrylic acid Chemical compound

Methacrylic acid, abbreviated MAA, is an organic compound. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced industrially on a large scale as a precursor to its esters, especially methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA). MAA occurs naturally in small amounts in the oil of Roman chamomile.

<i>p</i>-Coumaric acid Chemical compound

p-Coumaric acid is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acid—o-coumaric acid, m-coumaric acid, and p-coumaric acid—that differ by the position of the hydroxy substitution of the phenyl group. p-Coumaric acid is the most abundant isomer of the three in nature. p-Coumaric acid exists in two forms trans-p-coumaric acid and cis-p-coumaric acid.

Platinum(II) chloride Chemical compound

Platinum(II) chloride is the chemical compound PtCl2. It is an important precursor used in the preparation of other platinum compounds. It exists in two crystalline forms, but the main properties are somewhat similar: dark brown, insoluble in water, diamagnetic, and odorless.

Angelicin Chemical compound

Angelicin is the parent compound in a family of naturally occurring organic compounds known as the angular furanocoumarins. Structurally, it can be considered as benzapyra-2-one fused with a furan moiety in the 7,8-position. Angelicin is commonly found in certain Apiaceae and Fabaceae plant species such as Bituminaria bituminosa. It has a skin permeability coefficient (LogKp) of -2.46. The maximum absorption is observed at 300 nm. The 1HNMR spectrum is available; the infrared and mass spectra of angelicin can be found in this database. The sublimation of angelicin occurs at 120 °C and the pressure of 0.13 Pa. Angelicin is a coumarine.

1-Octanol Chemical compound

1-Octanol, also known as octan-1-ol, is the organic compound with the molecular formula CH3(CH2)7OH. It is a fatty alcohol. Many other isomers are also known generically as octanols. 1-Octanol is manufactured for the synthesis of esters for use in perfumes and flavorings. It has a pungent odor. Esters of octanol, such as octyl acetate, occur as components of essential oils. It is used to evaluate the lipophilicity of pharmaceutical products.

Petroselinic acid is a fatty acid that occurs naturally in several animal and vegetable fats and oils. It is a white powder and is commercially available. In chemical terms, petroselinic acid is classified as a monounsaturated omega-12 fatty acid, abbreviated with a lipid number of 18:1 cis-6. It has the formula CH3(CH2)10CH=CH(CH2)4COOH. The term "petroselinic" means related to, or derived from, oil of Petroselinum, parsley. Despite its name, petroselinic acid does not contain any selenium. Petroselinic acid is a positional isomer of oleic acid.

Decenoic acid is any mono-carboxylic acid with an unbranched chain of ten carbons connected by eight single bonds and one double bond; that is, a chemical compound with formula HO(O=)C(CH
2
)
k
CH=CH(CH
2
)
7-k
–H, where k is between 0 and 7 inclusive.

2-Methylbutanoic acid, also known as 2-methylbutyric acid is a branched-chain alkyl carboxylic acid with the chemical formula CH3CH2CH(CH3)CO2H, classified as a short-chain fatty acid. It exists in two enantiomeric forms, (R)- and (S)-2-methylbutanoic acid. (R)-2-methylbutanoic acid occurs naturally in cocoa beans and (S)-2-methylbutanoic occurs in many fruits such as apples and apricots, as well as in the scent of the orchid Luisia curtisii.

References

  1. Buchner, L. A. (1842). "Ueber eine eigenthümliche flüchtige Säure aus der Angelicawurzel: Eine briefliche Mittheilung". Justus Liebigs Ann. Chem. 42 (2): 226–233. doi:10.1002/jlac.18420420211.
  2. 1 2 3 Rudolf Fritz Weiss Weiss's herbal medicine, Thieme, 2001, ISBN   1-58890-069-X pp. 46, 91, 236
  3. K. V. Peter Handbook of herbs and spices, Volume 2, Woodhead Publishing, 2004, ISBN   1-85573-721-3 p. 96
  4. 1 2 Sonobe, Hiromi; Kamps, Laverne R.; Mazzola, Eugene P.; Roach, John A. G. (1981). "Isolation and identification of a new conjugated carbofuran metabolite in carrots: angelic acid ester of 3-hydroxycarbofuran". Journal of Agricultural and Food Chemistry. 29 (6): 1125–9. doi:10.1021/jf00108a006. PMID   7320331.
  5. J. O. Braithwaite Year-book of pharmacy, J. & A. Churchill, 1887, p. 14
  6. 1 2 Ernest Small Culinary herbs, National Research Council Canada, 2006, ISBN   0-660-19073-7 p. 288
  7. Lyle E. Craker, James E. Simon Herbs, Spices, and Medicinal Plants: Recent Advances in Botany, Horticulture, and Pharmacology, Routledge, 1986, ISBN   1-56022-043-0 p. 257
  8. Henry Watts, Henry Forster Morley, Matthew Moncrieff Pattison Muir Watts' Dictionary of Chemistry, Volume 1, Longmans, Green, 1888, p. 266
  9. 1 2 3 William Allen Miller, Herbert McLeod Elements of Chemistry, Vol. 3: Chemical physics, p. 958
  10. Friedrich Wöhler Wöhler's Outlines of organic chemistry, p. 124
  11. Year-book of pharmacy, p. 92
  12. Pelletier, S. W.; McLeish, William L. (1952). "The Ultraviolet-induced Isomerization of Tiglic Acid to Angelic Acid". Journal of the American Chemical Society. 74 (24): 6292–6293. doi:10.1021/ja01144a518.
  13. Vickie Vaclavik, Vickie A. Vaclavik, Elizabeth W. Christian Essentials of food science, Springer, 2007, ISBN   0-387-69939-2, p. 282
  14. D. Nasipuri Stereochemistry of Organic Compounds: Principles and Applications, New Age International, 1994, ISBN   81-224-0570-3, p. 192