MALIC ACID

CAS Number:6915-15-7 
EC Number:210-514-9

synonyms:
calcium (hydroxy-1-malate) hexahydrate; malate; malic acid; malic acid, (R)-isomer; malic acid, calcium salt, (1:1), (S)-isomer; malic acid, disodium salt; malic acid, disodium salt, (R)-isomer; malic acid, disodium salt, (S)-isomer; malic acid, magnesium salt (2:1); malic acid, monopotassium salt, (+-)-isomer; malic acid, potassium salt, (R)-isomer; malic acid, sodium salt, (+-)-isomer; DL-malic acid; 6915-15-7; 2-Hydroxybutanedioic acid; 2-Hydroxysuccinic acid; malate; hydroxysuccinic acid; Butanedioic acid, hydroxy-; 617-48-1; Kyselina jablecna; Pomalus acid; hydroxybutanedioicacid; Deoxytetraric acid; Malic acid, DL-; Musashi-no-Ringosan; alpha-Hydroxysuccinic acid; E296; Monohydroxybernsteinsaeure; Succinic acid, hydroxy-; R,S(+-)-Malic acid; dl-Hydroxybutanedioic acid; 2-Hydroxyethane-1,2-dicarboxylic acid; Kyselina jablecna [Czech]; FDA 2018; (+-)-Malic acid; Hydroxy Succinic Acid; FEMA Number 2655; Kyselina hydroxybutandiova [Czech]; Malic acid [NF];DL-Apple Acid; H2mal; Hydroxybutanedioic acid homopolymer; 2-Hydroxysuccinate; R,S-Malic acid; Racemic malic acid; R,S-Malate; ( )-Malic acid; ( C)-Malic acid; (+)-Malic acid;Opera_ID_805; 2-hydroxyl-succinic acid; DL-Malic acid, 99%; MALIC ACID,(DL); 2-Hydroxydicarboxylic acid; SCHEMBL856; Oprea1_130558; Oprea1_624131; KSC353M3D; DL-HYDROXYSUCOINIC ACID; AC1Q778R; Butanedioic acid, (.+-.)-; DL(+/-)-MALICACID; GTPL2480; DL-HYROXYBUTANEDIOIC ACID; CHEMBL1455497;Butanedioic acid, hydroxy-; α-Hydroxysuccinic acid; Hydroxyethane-1,2-dicarboxylic acid; Hydroxysuccinic acid; Pomalus acid; dl-Malic acid; Deoxytetraric acid; Kyselina hydroxybutandiova; Kyselina jablecna; Succinic acid, hydroxy-; Hydroxybutanedioic acid; (.+/-.)-Malic acid; 2-Hydroxyethane-1,2-dicarboxylic acid; Butanedioic acid, 2-hydroxy-; FDA 2018; Musashi-no-Ringosan; NSC 25941; R,S(.+/-.)-Malic acid; Apple acid (Salt/Mix); malic acid; DL-malic acid; 6915-15-7; 2-Hydroxybutanedioic acid ; 2-Hydroxysuccinic acid; 617-48-1malate; Butanedioic acid, hydroxy-; hydroxysuccinic acid; Deoxytetraric acid; hydroxybutanedioic acid; Pomalus acid; Malic acid, DL-
alpha-Hydroxysuccinic acid; Hydroxybutandisaeure; dl-Hydroxybutanedioic acid; Caswell No. 537; Monohydroxybernsteinsaeure; Succinic acid, hydroxy-; R,S(+-)-Malic acid; 2-Hydroxyethane-1,2-dicarboxylic acid; FDA 2018; (+-)-Malic acid; FEMA No. 2655; EINECS 210-514-9; EINECS 230-022-8; NSC 25941; (-)-Malic acid; (+-); Hydroxysuccinic acid; R,SMalate; DL-Apple Acid; Hydroxybutanedioic acid homopolymer; 2-Hydroxysuccinik asit; L-Malik asit; D-Malik asit; (–)-Malik asit; (+)-Malik asit; (S)-Hydroxybutanedioik asit; (R)-Hydroxybutanedioik asit; 2-Hydroxysuccinate; (+/-)-Malic acid; Opera_ID_805; 2-hydroxyl-succinic acid; malik asit; malic acit; malic acid; malic acide; malik asid; acide malique; acide maleique; l'acide malique; L'acide maleique; malic asit; malic acit; malic acite
 

MALIC ACID
Malic acid

Properties of malic acid

Molecular Formula: C4H6O5
Melting Point: 127-132 °C
Molecular Weight: 134.09 g/mol

  Malic acid is a component of many of the foods that we eat daily. Although it is found as a naturally occurring organic compound in various fruits, many choose to take malic acid supplements to increase their overall health, as well as treat various maladies. Today, the acid is most commonly used as a food additive and preservative. It is a mild and relatively harmless acid when used in appropriate amounts. As a food supplement, it is generally considered beneficial for health and is present in large amounts in apple juices. As when taking any supplement, however, you should not exceed the recommended amounts for consumption.

Benefits of Malic Acid

  One of its most commonly touted benefits is its ability to help reduce pain. For this reason, it is frequently used by those who suffer from fibromyalgia and chronic fatigue system. Those who take it for this reason have reported reduced muscle soreness and pain. Although it takes several days of consistent consumption for the supplement to take full effect, it can start to reduce pain as quickly as 48 hours after your first supplement.

  The most popular sporting supplements are those that naturally and safely improve your performance in terms of endurance, stamina, your ability to recoverand your motivation. Malic acid is commonly found in such supplements for its capacity to ward off fatigue and boost your endurance.  

Foods Containing Malic Acid 

  The food that is most well known for its high malic acid content is the apple. Other fruits with a very high concentration of the acid are nectarines, cherries, lychees, bananas, mangoes, peaches, tomatoes and strawbesrries. It can be found, however, in nearly all fruits.

 Malic acid is also used as a flavor enhancer for many drinks and candies. It is especially common in diet sodas and other artificially sweetened drinks. This is also true of artificially sweetened candies, such as gum and other gummy candies. Because of its highly versatile nature, especially in masking unnatural flavors, it has become an important part of nearly any food product that contains alternative sweeteners.

  One of the greatest things about malic acid as both a food supplement and a skincare agent is the fact that it is a completely natural, organic compound. Rather than relying on man-made products to improve the health of your body and skin, it provides a natural alternative for a variety of purposes. Whether you are treating your chronic fatigue, fibromyalgia or just some dry skin, this acid is a safe and readily available solution. Because of its powerful pain relieving and healing properties, it has become a very popular, and viable solution for many people in the treatment of their various maladies. This has only been amplified by its overall safety.
Side Effects

  Although generally regarded as a very safe and effective supplement, there can be some minor side effects. The most common of these, while uncomfortable, are only experienced by a small number of those who use the supplement. The side effects most frequently experienced include muscle pain, nausea, redness, constipation, swollen skin, chest pain and itching. While annoying, these typically dissipate after a couple days.

  While most of the side effects are relatively minor, there are also some more serious side effects, which are very rare. These serious side effects are often more serious forms of their minor counterparts, such as extreme chest tightness. This also includes dangerous events such as allergic reaction, which can lead to difficulty breathing or a completely closed throat. If you experience any of these, seek medical help immediately.

Not to be confused with maleic acid or malonic acid.
"Malate" redirects here. For the district in Manila, see Malate, Manila.
Malic acid
Skeletal structure
Ball-and-stick model
Sample of racemic malic acid.jpg
DL-Malic acid
Names
Preferred IUPAC name
2-Hydroxybutanedioic acid
Other names
Hydroxybutanedioic acid
2-Hydroxysuccinic acid
L-Malic acid
D-Malic acid
(–)-Malic acid
(+)-Malic acid
(S)-Hydroxybutanedioic acid
(R)-Hydroxybutanedioic acid
Identifiers
CAS Number
617-48-1 ☒
6915-15-7 ☒
3D model (JSmol)
Interactive image
ChEBI    
CHEBI:6650 ☑
ChEMBL    
ChEMBL1455497 ☒
ChemSpider    
510 ☑
83793 D-(+)-malic acid ☑
193317 L-(–)-malic acid ☑
ECHA InfoCard    100.027.293
EC Number    
230-022-8
E number    E296 (preservatives)
IUPHAR/BPS
2480
KEGG    
C00149 ☒
PubChem CID
525
UNII    
817L1N4CKP ☑
CompTox Dashboard (EPA)
DTXSID0027640 Edit this at Wikidata
InChI[show]
SMILES[show]
Properties
Chemical formula
C4H6O5
Molar mass    134.087 g·mol−1
Density    1.609 g⋅cm−3
Melting point    130 °C (266 °F; 403 K)
Solubility in water
558 g/L (at 20 °C)[1]
Acidity (pKa)    pKa1 = 3.40
pKa2 = 5.20[2]
Related compounds
Other anions
Malate
Related carboxylic acids
Succinic acid
Tartaric acid
Fumaric acid
Related compounds
Butanol
Butyraldehyde
Crotonaldehyde
Sodium malate
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
Malic acid is an organic compound with the molecular formula C4H6O5. It is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms (L- and D-enantiomers), though only the L-isomer exists naturally. The salts and esters of malic acid are known as malates. The malate anion is an intermediate in the citric acid cycle.

Etymology
The word 'malic' is derived from Latin 'malus', meaning 'apple'. It is also the name of the genus Malus, which includes all apples and crabapples; and the origin of other taxonomic classifications such as Maloideae, Malinae, and Maleae. This derivation is also seen as well as in the traditional German name for malic acid, 'Äpfelsäure' meaning 'apple acid' as well as in modern Greek, 'mēlicon oxy' (Μηλικόν οξύ), after the original European discovery of apples in modern-day Kazakhstan 2350 years ago by Alexander the Great's expeditionary foray into Asia.

Biochemistry
L-Malic acid is the naturally occurring form, whereas a mixture of L- and D-malic acid is produced synthetically.

L-Malic acid
 

D-Malic acid
Malate plays an important role in biochemistry. In the C4 carbon fixation process, malate is a source of CO2 in the Calvin cycle. In the citric acid cycle, (S)-malate is an intermediate, formed by the addition of an -OH group on the si face of fumarate. It can also be formed from pyruvate via anaplerotic reactions.

Malate is also synthesized by the carboxylation of phosphoenolpyruvate in the guard cells of plant leaves. Malate, as a double anion, often accompanies potassium cations during the uptake of solutes into the guard cells in order to maintain electrical balance in the cell. The accumulation of these solutes within the guard cell decreases the solute potential, allowing water to enter the cell and promote aperture of the stomata.

In food
Malic acid was first isolated from apple juice by Carl Wilhelm Scheele in 1785.[3] Antoine Lavoisier in 1787 proposed the name acide malique, which is derived from the Latin word for apple, mālum—as is its genus name Malus.[4][5] In German it is named Äpfelsäure (or Apfelsäure) after plural or singular of the fruit apple, but the salt(s) Malat(e). Malic acid is the main acid in many fruits, including apricots, blackberries, blueberries, cherries, grapes, mirabelles, peaches, pears, plums, and quince[6] and is present in lower concentrations in other fruits, such as citrus.[7] It contributes to the sourness of unripe apples. Sour apples contain high proportions of the acid. It is present in grapes and in most wines with concentrations sometimes as high as 5 g/l.[8] It confers a tart taste to wine; the amount decreases with increasing fruit ripeness. The taste of malic acid is very clear and pure in rhubarb, a plant for which it is the primary flavor. It is also a component of some artificial vinegar flavors, such as "salt and vinegar" flavored potato chips.[9]

In citrus, fruits produced in organic farming contain higher levels of malic acid than fruits produced in conventional agriculture.[7]

The process of malolactic fermentation converts malic acid to much milder lactic acid. Malic acid occurs naturally in all fruits and many vegetables, and is generated in fruit metabolism.[10]

Malic acid, when added to food products, is denoted by E number E296. Malic acid is the source of extreme tartness in United States-produced confectionery, the so-called extreme candy. It is also used with or in place of the less sour citric acid in sour sweets. These sweets are sometimes labeled with a warning stating that excessive consumption can cause irritation of the mouth. It is approved for use as a food additive in the EU,[11] US[12] and Australia and New Zealand[13] (where it is listed by its INS number 296).

Malic acid provides 10 kJ (2.39 Calories) of energy per gram during digestion.[14]

Production and main reactions
Racemic malic acid is produced industrially by the double hydration of maleic anhydride. In 2000, American production capacity was 5000 tons per year. Both enantiomers may be separated by chiral resolution of the racemic mixture, and the (S)- enantiomer may be specifically obtained by fermentation of fumaric acid.[15]

Self-condensation of malic acid with fuming sulfuric acid gives the pyrone coumalic acid:[16]

Coumalic Acid Synthesis
Malic acid was important in the discovery of the Walden inversion and the Walden cycle, in which (−)-malic acid first is converted into (+)-chlorosuccinic acid by action of phosphorus pentachloride. Wet silver oxide then converts the chlorine compound to (+)-malic acid, which then reacts with PCl5 to the (−)-chlorosuccinic acid. The cycle is completed when silver oxide takes this compound back to (−)-malic acid.

See also
Acids in wine
Crassulacean acid metabolism
Malate-aspartate shuttle

The Health Benefits of Malic Acid
Malic acid is a substance found naturally in apples and pears. It's considered an alpha-hydroxy acid, a class of natural acids commonly used in skin-care products. Also sold in dietary supplement form, malic acid is said to offer a variety of benefits.

Health Benefits
Malic acid is found in fruits and vegetables and is produced naturally in the body when carbohydrates are converted into energy. While some research suggests that malic acid supplements may help people with certain conditions, high-quality clinical trials are needed.

There's some evidence that malic acid supplements may offer these benefits:

Skin-Care Benefits
When applied to the skin, malic acid is said to reduce signs of aging, remove dead skin cells, aid in the treatment of acne, and promote skin hydration.

A number of early studies published in the 1990s and early 2000s indicate that malic acid may be beneficial when applied to the skin. In tests on animals and human cells, the studies' authors found that malic acid may help increase collagen production and reverse sun-induced signs of skin aging.

More recent research on topically applied malic acid includes a small study published in the Journal of Drugs in Dermatology in 2013.1 For the study, researchers assigned people with melasma (a common disorder marked by patches of abnormally dark skin) to a skin-care regimen that included the use of topical vitamin C and malic acid. At an average follow-up of 26 months, the regimen was found to be an effective short-term treatment for melasma.

Physical Performance
Malic acid is also used to boost sports performance when taken in supplement form. It is sometimes combined with creatine supplements in order to improve the body's absorption of creatine. Proponents claim that malic acid can promote energy production, increase exercise endurance, and help fight off muscle fatigue.

For a study published in Acta Physiologica Hungarica in 2015, researchers investigated the effectiveness of a creatine-malate supplement in sprinters and long-distance runners.2 After six weeks of supplementation combined with physical training, there was a significant increase in the physical performance in sprinters, measured by peak power, total work, body composition, and elevated growth hormone levels. In long-distance runners, there was a significant increase in distance covered.

Kidney Stones

Malic acid is a precursor to citrate, a substance believed to prevent calcium from binding with other substances in urine that form kidney stones. Citrate may also prevent crystals from getting bigger by preventing them from sticking together.

According to a preliminary laboratory study published in 2014, malic acid consumption may increase urine pH and citrate levels, making stone formation less likely. The study authors concluded that malic acid supplementation may be useful for the conservative treatment of calcium kidney stones.3

In a 2016 review, scientists suggested that given the high malic acid content in pears, future research should explore whether a diet supplemented with pears and low in meat and sodium may reduce stone formation.4

Fibromyalgia
A pilot study published in the Journal of Rheumatology in 1995 found that taking malic acid in combination with magnesium helped alleviate pain and tenderness in people with fibromyalgia.5

For the study, researchers assigned 24 people with fibromyalgia to treatment with either a placebo or a combination of malic acid and magnesium. After six months, those treated with the malic acid/magnesium combination showed a significant improvement in pain and tenderness. However, there's a lack of more recent research on malic acid's effectiveness as a fibromyalgia treatment.

Dry Mouth
The use of a one percent oral malic acid spray has been explored as a treatment for dry mouth. A study published in Depression and Anxiety, for instance, evaluated a one percent malic acid spray compared to a placebo in people with dry mouth resulting from antidepressant use.6 After two weeks of using the sprays when needed, those using the malic acid spray had improved dry mouth symptoms and increased saliva flow rates.

Possible Side Effects
Due to a lack of research, little is known about the safety of long-term or regular use of malic acid supplements. However, there's some concern that intake of malic acid may trigger certain side effects such as headaches, diarrhea, nausea, and allergic reactions.

Although malic acid is generally considered safe when applied to the skin in the recommended amount, some people may experience irritation, itching, redness, and other side effects. It's a good idea to patch test new products.

In addition, alpha-hydroxy acids are known to increase your skin's sensitivity to sunlight.7 Therefore, it's important to use sunscreen in combination with skin-care products containing any type of alpha-hydroxy acid.

Keep in mind that malic acid shouldn't be used as a substitute for standard care. Self-treating a condition and avoiding or delaying standard care may have serious consequences.

Dosage and Preparation
There is no standard dose of malic acid that is recommended. Various doses have been used with adults in studies to investigate the treatment of different conditions.

For example, for fibromyalgia, a product called Super Malic (malic acid 1200 mg and magnesium hydroxide 300 mg) was taken twice daily for six months.

 For acne, a cream containing malic acid and arginine glycolate was applied twice daily for 60 days. And lastly, for dry mouth, a mouth spray containing 1 percent malic acid, 10 percent xylitol, and 0.05 percent fluoride was used up to eight times daily for two weeks.

The appropriate dose for you may depend on how you are using the supplement, your age, gender, and medical history. Speak to your healthcare provider for personalized advice.

What to Look For
Malic acid is found naturally in fruits including apricots, blackberries, blueberries, cherries, grapes, peaches, pears, and plums. Malic acid is also found in some citrus fruits.

In food, malic acid may be used to acidify or flavor foods or prevent food discoloration. It may also be used with other ingredients in cosmetics.

Using malic acid as part of your skin care routine may help with concerns such as pigmentation, acne, or skin aging. But keep in mind that it's a good idea to patch test when using new products and to avoid the eye area.

If you choose to take a malic acid supplement, the National Institutes of Health (NIH) offers tips to consumers. The organization recommends that you look for a Supplement Facts label on the product. This label will contain vital information including the amount of active ingredients per serving, and other added ingredients.

Lastly, the organization suggests that you look for a product that contains a seal of approval from a third party organization that provides quality testing. These organizations include U.S. Pharmacopeia, ConsumerLab.com, and NSF International. A seal of approval from one of these organizations does not guarantee the product's safety or effectiveness but it does provide assurance that the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants.
Overview Information
Malic acid is a chemical found in certain fruits and wines. It is sometimes used as medicine.

Malic acid is used most commonly for dry mouth. It is also used for fibromyalgia, fatigue, and skin conditions, but there is no good scientific evidence to support these other uses.

In foods, malic acid is used as a flavoring agent to give food a tart taste.

In manufacturing, malic acid is used to adjust the acidity of cosmetics.

How does it work?
Malic acid is involved in the Krebs cycle. This is a process the body uses to make energy. Malic acid is sour and acidic. This helps to clear away dead skin cells when applied to the skin. Its sourness also helps to make more saliva to help with dry mouth.
Uses & Effectiveness?
Possibly Effective for
Dry mouth. Using a mouth spray containing a malic acid seems to improve symptoms of dry mouth better than using a saline mouth spray.
Insufficient Evidence for
Acne. Early research shows that applying an alpha hydroxy acid cream containing malic acid helps reduce signs of acne in some people.
Fibromyalgia. Taking malic acid in combination with magnesium seems to reduce pain and tenderness caused by fibromyalgia.
Fatigue.
Warts.
Scaly, itchy skin (psoriasis).
Aging skin.
Other conditions.
More evidence is needed to rate the effectiveness of malic acid for these uses.
Side Effects & Safety
When taken by mouth: Malic acid is LIKELY SAFE when taken by mouth in food amounts. Malic acid is POSSIBLY SAFE when taken by mouth as a medicine.

When applied to the skin: There isn't enough reliable information to know if malic acid is safe. It might cause side effects such as skin and eye irritation.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Malic acid is LIKELY SAFE when taken by mouth in food amounts. There isn't enough reliable information to know if malic acid is safe to use as medicine when pregnant or breast-feeding. Stay on the safe side and avoid in amounts greater than what is normally found in food.

Low blood pressure: Malic acid might lower blood pressure. In theory, malic acid might increase the risk of blood pressure becoming too low in people prone to low blood pressure.

Malic Acid
Malic acid is a crystalline white solid with a melting point of 100°C. It is water soluble and less hygroscopic as compared to others, so as to provide a good storage shelf-life.

From: Recent Trends in Soft Beverages, 2011

Related terms:
Citric AcidSuccinic AcidMalolactic FermentationGlucoseMetabolismEnzymesFermentationYeastsTartaric Acid