PARA-AMINOBENZOIC ACID

PARA-AMINOBENZOIC ACID = 4-AMINOBENZOIC ACID = p-AMINOBENZOIC ACID 

CAS Number: 150-13-0
EC Number: 205-753-0
MDL number: MFCD00007894
Molecular Formula: C7H7NO2

4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the para position) is an organic compound with the formula H2NC6H4CO2H. 
PABA is a white solid, although commercial samples can appear gray. 
PARA-AMINOBENZOIC ACID is slightly soluble in water. 
PARA-AMINOBENZOIC ACID consists of a benzene ring substituted with amino and carboxyl groups. 
PARA-AMINOBENZOIC ACID occurs extensively in the natural world.

4-aminobenzoic acid is an aminobenzoic acid in which the amino group is para to the carboxy group. 
4-aminobenzoic acid has a role as an Escherichia coli metabolite, a plant metabolite and an allergen. 
4-aminobenzoic acid derives from a benzoic acid. 
4-aminobenzoic acid is a conjugate acid of a 4-aminobenzoate.
Aminobenzoic Acid is an organic acid with UV absorption and antifibrotic properties. 

When exposed to light, aminobenzoic acid (para-aminobenzoic acid or PABA) absorbs UV light and emits excess energy via a photochemical reaction that may cause damage to DNA. 
Aminobenzoic acid is no longer widely used in sunscreen formulations. 
Aminobenzoic acid may also increase oxygen uptake at the tissue level and may enhance monoamine oxidase (MAO) activity to promote the degradation of serotonin, which in excess, may lead to fibrotic changes.
Para-aminobenzoic acid (PABA), also called aminobenzoic acid, a vitamin-like substance and a growth factor required by several types of microorganisms. 

PABA is not an essential nutrient for vertebrates, since they do not synthesize their own folic acid. 
PABA is present in high concentrations in brewer’s yeast, and PABA is perhaps best-known as an ultraviolet screen and as an active ingredient of some sun lotions.
Para-aminobenzoic acid (PABA), also known as vitamin B10, is an organic compound found in certain foods and produced by the chemical industry.
Vitamin B10 (or vitamin Bx) is an alternative name for the organic compound PABA, a white crystalline substance.
Para-aminobenzoic acid or PABA as Para-aminobenzoic acid is more commonly known, is a chemical substance that is found in the folic acid vitamin and also in several foods including grains, eggs, milk, molasses, liver and kidney.

The para-aminobenzoic acid (PABA) is an amphoteric component that has three forms in an aqueous solution. 
PABA can titrate with strong acid or a strong base. 
p-Aminobenzoic acid, also known as PABA or p-aminobenzoate, belongs to the class of organic compounds known as aminobenzoic acids. 
These are benzoic acids containing an amine group attached to the benzene moiety. 
p-Aminobenzoic acid is a moderately basic compound (based on its pKa). 
p-Aminobenzoic acid exists in all living species, ranging from bacteria to humans. 
Outside of the human body, p-Aminobenzoic acid is found, on average, in the highest concentration within pineapples. 

p-Aminobenzoic acid has also been detected, but not quantified in, milk (cow) and rices. 
This could make p-aminobenzoic acid a potential biomarker for the consumption of these foods. 
An aminobenzoic acid in which the amino group is para to the carboxy group.
Para-aminobenzoic acid (PABA), which is a component of pteroylglutamate, was formerly believed to be a vitamin and was often referred to as vitamin B-X due to Para-aminobenzoic acid's role as a provitamin for some bacteria. 
Para aminobenzoic acid is also known as aminobenzoic acid or 4-aminobenzoic acid. 

Para aminobenzoic acid is considered a growth factor in several microorganisms. 
For example, Para aminobenzoic acid is used in the synthesis of folic acid in bacteria. 
Folic acid is important in the synthesis of bacteria. 
Therefore, the drug sulfanilamide is generally administered during bacterial infection since Para aminobenzoic acid targets the process of bacterial utilization of Para aminobenzoic acid during folic acid synthesis in these organisms.
Para aminobenzoic acid is one of the chief constituents in the process of DNA synthesis in different organisms like bacteria, fungi, and plants. 

Even E.coli, the bacteria found in the human intestine, can produce Para aminobenzoic acid. 
Plants can produce PABA and folic acid in their chloroplast. 
However, humans cannot produce Para aminobenzoic acid in their cells. 
They lack the enzyme required for folic acid synthesis. 
Therefore, they require Para aminobenzoic acid as a food supplement, like green leafy vegetables.
PABA or para-aminobenzoic acid is an organic compound. 
Para aminobenzoic acid is also known as Vitamin B10. 

Para aminobenzoic acid is white, crystalline solid, slightly soluble in water. 
In our body, Para aminobenzoic acid is required for the formation of Folic acid synthesis. 
Therefore, Para aminobenzoic acid is essential in our body.  
Para aminobenzoic acid can be obtained from several foods like meat, milk, cheeses, and other dairy products. 
Para aminobenzoic acid is believed that taking the oral dose of PABA is as equally effective as applying on the skin for sun-screening action
PABA, or para-aminobenzoic acid, is a naturally occurring non-protein amino acid. 
Although PABA is sometimes referred to as a vitamin, Para aminobenzoic acid is not actually a vitamin and not an essential nutrient for humans. 

PABA is perhaps best-known for Para aminobenzoic acid's role as an ingredient in sunscreens; however, Para aminobenzoic acid can also be supplemented orally, and Para aminobenzoic acid occurs naturally in some food sources. 
As long as PABA is consumed in recommended doses, it is considered safe.
PABA naturally occurs in some food sources, which include brewer's yeast, whole grains, spinach, mushrooms, molasses and liver. 
Small amounts of PABA can sometimes be found in B-vitamin supplements and multivitamins. 
In supplemental form, PABA is usually found in doses of 500 to 1,000 milligrams.
Para-aminobenzoic acid (PABA) is a compound formed by replacing the para (4-position) on the benzene ring of benzoic acid with an amino group.
Para-aminobenzoic acid is one of the constituents of folic acid, which is necessary for the growth and division of the body's cells. 

Para-aminobenzoic acid is synthesized by the shikimic acid pathway via branched acids. 
The first reaction step is the reaction of a branched acid with ammonia to form 4-amino-4-deoxy branched acid, which is catalyzed by an amino deoxy branched acid synthetase. 
The 4-amino-4-deoxy branched acid then eliminates one pyruvate and is aromatized to p-aminobenzoic acid.
Para-aminobenzoic acid is a white crystalline powder or colourless crystals, freely soluble in alcohol, slightly soluble in water. 
Para-aminobenzoic acid is used to get rid of the pain caused by wounds, ulcers, and in mucous surface. 
There are three structural isomers: amino group substituted benzoic acid at relative to the hydroxyl group, ortho-, meta-, and para-Aminobenzoic acid. 
The names of the three compounds indicate which of the hydrogens on the benzene ring portion of the molecule have been replaced. 

Aminobenzoic acids their derivatives are important for the preparation of other pharmaceutical products, dyes, flavours, and preservatives.
p-Aminobenzoic acid is a part of folic acid molecule. 
p-Aminobenzoic acid was called Vitamin BX as it is a component of pteroylglutamate.
Para-Aminobenzoic Acid, also known as PABA, is a non-protein amino acid and is also an unofficial member of the vitamin-B complex group of vitamins although Para-Aminobenzoic Acid is not technically a vitamin. 
Para-Aminobenzoic Acid is, in fact, an intermediate in the folic acid pathway in bacteria which is an important pathway for nucleic acid synthesis. 

Para-Aminobenzoic Acid is found in trace amounts in the following foods: whole grains and foods of animal origin, especially brewer's yeast, wheat germ, bran, and liver, eggs, molasses and mushrooms, spinach.
Paraaminobenzoic acid, PABA for short, is an aromatic hydrocarbon compound with the molecular formula C7H7NO2. 
Paraaminobenzoic acid is easily soluble in water, ether and ethanol. 
Paraaminobenzoic acid was formerly also called vitamin H. 
Paraaminobenzoic acid is a weak organic acid which is present at room temperature as an odourless, slightly yellowish solid which turns brown under the influence of light.

USES and APPLICATIONS of PARA-AMINOBENZOIC ACID:
-Para-aminobenzoic acid (PABA) is a chemical found in the folic acid vitamin and also in several foods including grains, eggs, milk, and meat.
-PABA is taken by mouth for skin conditions including vitiligo, pemphigus, dermatomyositis, morphea, lymphoblastoma cutis, Peyronie's disease, and scleroderma. 
-PABA is also used to treat infertility in women, arthritis, "tired blood" (anemia), rheumatic fever, constipation, systemic lupus erythematosus (SLE), and headaches. 
-Para-aminobenzoic acid is also used to darken gray hair, prevent hair loss, make skin look younger, and prevent sunburn.

-PABA is best known as a sunscreen that is applied to the skin (used topically).
-PABA is used as a sunscreen because Para-aminobenzoic acid can block ultraviolet (UV) radiation to the skin.
-Para-aminobenzoic acid (PABA) is a chemical that occurs naturally in the body. 
-Para-aminobenzoic acid is also found in several foods including grains, eggs, milk, and meat.
-PABA is taken for a disease that causes curved, painful erections (Peyronie disease), a rare autoimmune disorder that causes skinblisters (pemphigus), hardening of skin and connective tissue (scleroderma), and many other conditions. 

-PABA is best known as a sunscreen that is applied to the skin.
-PABA is an intermediate in the synthesis of folate by bacteria, plants, and fungi. 
Many bacteria, including those found in the human intestinal tract such as E. coli, generate PABA from chorismate by the combined action of the enzymes 4-amino-4-deoxychorismate synthase and 4-amino-4-deoxychorismate lyase. 
Plants produce PABA in their chloroplasts, and store Para-aminobenzoic acid as a glucose ester (pABA-Glc) in their tissues. 
Humans lack the enzymes to convert PABA to folate, so require folate from dietary sources such as green leafy vegetables. 
In humans, PABA is considered nonessential and, although Para-aminobenzoic acid has been referred to historically as "vitamin Bx", is no longer recognized as a vitamin, because most people have a microbiome that will generate PABA.

-Sulfonamide drugs are structurally similar to PABA, and their antibacterial activity is due to their ability to interfere with the conversion of PABA to folate by the enzyme dihydropteroate synthetase. 
Thus, bacterial growth is limited through folate deficiency.
-The potassium salt is used as a drug against fibrotic skin disorders, such as Peyronie's disease, under the trade name Potaba. 
PABA is also occasionally used in pill form by sufferers of irritable bowel syndrome to treat its associated gastrointestinal symptoms, and in nutritional epidemiological studies to assess the completeness of 24-hour urine collection for the determination of urinary sodium, potassium, or nitrogen levels.

-Despite the lack of any recognized syndromes of PABA deficiency in humans, except for those who lack the colonic bacteria that generate PABA, many claims of benefit are made by commercial suppliers of PABA as a nutritional supplement. 
The benefit is claimed for fatigue, irritability, depression, weeping eczema (moist eczema), scleroderma (premature hardening of the skin), patchy pigment loss in the skin (vitiligo), and premature grey hair.
-In bacteria, PABA is used in the synthesis of the vitamin folic acid. 
The drug sulfanilamide is effective in treating some bacterial diseases because it prevents the bacterial utilization of PABA in the synthesis of folic acid.

-Para-aminobenzoic acid (PABA) is a natural substance. 
Para-aminobenzoic acid is often used in sunscreen products. 
PABA is sometimes called vitamin Bx, but Para-aminobenzoic acid is not a true vitamin.
-Para-aminobenzoic acid’s considered part of the vitamin B complex, although Para-aminobenzoic acid’s not a vitamin nor an essential nutrient. 
Para-aminobenzoic acid’s found in brewer’s yeast, organ meat, mushrooms, whole grains, and spinach.
-Human body can also synthesize the compound using certain bacteria in your gut. 
PABA then assists in the production of folate (vitamin B9). 
Yet, the amount of folate produced is inadequate to meet your needs, so you need to obtain Para-aminobenzoic acid from other dietary sources.

-PABA is thought to benefit skin and hair when taken as a supplement. 
-Para-aminobenzoic acid’s industrially produced and sold in pill, powder, extract, and topical application form.
-PABA can absorb ultraviolet (UV) rays — especially UVB rays, which are associated with sunburns and DNA damage. 
Since 2019, PABA is generally recognized as safe and effective for use in sunscreen by the Food and Drug Administration (FDA).
-Para-aminobenzoic acid’s sometimes found in certain lotions and other products marketed as moisturizers, often in combination with aloe vera, and Para-aminobenzoic acid’s rarely used in shampoos, conditioners, and lipsticks.
-PABA (p-aminobenzoic acid) is an important substrate for the synthesis of various biological scaffolds. 
Para-aminobenzoic acid's pharmacological significance is apparent form the drugs like folic acid and benzocaine, which are used for certain biological disorders. 

-Although, PARA-AMINOBENZOIC ACID is not a vitamin but still PARA-AMINOBENZOIC ACID is referred as a member of vitamin B. 
The deficiency of PABA leads to several disorders like erratic white areas of skin, grey hair, fatigue, depression and irritability. 
Besides PARA-AMINOBENZOIC ACID's medicinal importance, PABA has been used in the synthesis of various biologically active heterocyclic nuclei like benzimidazoles, azitidinones, thiazolidinones, pyrazoline, etc. 
This review will describe the applications of PABA in the synthesis of these biologically active nuclei and hence emphasizing PARA-AMINOBENZOIC ACID's importance as a versatile substrate.
-Para-aminobenzoic acid (PABA) is best known as the active ingredient in sunblock. 
This use of PABA is not really medicinal: like a pair of sunglasses, PABA physically blocks ultraviolet rays when Para-aminobenzoic acid is applied to the skin.

-There are, however, some proposed medicinal uses of oral PABA supplements. 
PABA is sometimes suggested as a treatment for various diseases of the skin and connective tissue, as well as for male infertility. 
-PABA is not believed to be an essential nutrient. 
Nonetheless, Para-aminobenzoic acid is found in foods, mainly in grains and meat. 
Small amounts of PABA are usually present in B vitamin supplements as well as in some multiple vitamins.
-Para-aminobenzoic acid (PABA) is a compound found in milk, eggs, grains, and meat. 
-Para-aminobenzoic acid is best known as the active ingredient in sunscreen. 
-PABA has been used to improve discoloration in skin and hair and to ease digestion. 

-Para-aminobenzoic acid can be taken as a pill, powder, or extract.
-PABA is also prepared industrially for use in sunscreen and local anaesthetic agents. 
PABA was found to have UVB absorbing properties and in 1943 was patented and became one of the first active ingredients to be used in sunscreen products. 
-PABA and PABA derivatives are commonly used in sunscreens as ultraviolet B (UVB) filters.
-Para-aminobenzoic acid (PABA) has long been used as an objective measure to assess completeness of 24-hour urine collections. 

-PABA falls in the category of ‘organic sunscreens’ wherein Para-aminobenzoic acid absorbs the harmful UVB rays. 
Sun rays can be divided into a spectrum of waves of different wavelengths. 
Thankfully, many of the harmful radiations are blocked by our atmosphere and the ozone layer. 
The visible spectrum, which reaches our skin, can be further divided into UVA, UVB, And UVC. 
UVC is again filtered by the environment.  
UVB rays when reaching our skin is short-acting and can cause hyperpigmentation, and tanning effect. 
UVA comes into action when the skin is exposed for longer than usual to the sunlight. 
Para-aminobenzoic acid goes much into deep and may change the skin protein structure and function. 
PABA is a chemical-based sunscreen and absorbs UVB rays and converts the effect as heat energy.  
Para-aminobenzoic acid reduces hyperpigmentation, wrinkles, and fine lines formed on the skin due to photoaging. 
Para-aminobenzoic acid is also used to protect the product from deteriorating due to exposure to sunlight. 
Para-aminobenzoic acid is used in formulations of skin care and sun protection products.

-Although PABA is most commonly applied topically as a sunscreen, according to WebMD, Para-aminobenzoic acid can also be taken by mouth for a number of skin conditions, including: vitiligo, scleroderma, morphea, lymphoblastoma cutis, dermatomyositis, Peyronie’s disease and pemphigus. 
-PABA is also used for infertility in women, constipation, arthritis, preventing hair loss, rheumatic fever and headaches. 
-In industrial field, Para-aminobenzoic acid is a starting material in the manufacture of target esters, salts, folic acid, azo dyes and other organic compounds. 
-Para-aminobenzoic acid is used as an UV-blocking ingredient in sun tan cosmetics. 
-Para-aminobenzoic acid is used in medical field for preparing local anesthetic and ointments.  

-In humans, PABA is believed to have antifibrosis effects due to an ability to increase oxygen consumption by tissues.
-PABA is used in many sunscreen products to block ultraviolet radiation.
-The p-aminobenzoic acid serves as a food supplement under the name PABA. 
-Para-aminobenzoic acid is the starting substance for e.g. local anaesthetics: benzocaine, cycloform, procaine.
-In cosmetics p-aminobenzoic acid serves as UVB absorber.
-In technical areas the substance is the starting product for azo dyes.
-The absorption via the skin is low. 
Orally absorbed PABA is metabolized by the organism to paraaminohippuric acid.

CHEMICAL PROPERTIES of PARA AMINOBENZOIC ACID:
Para aminobenzoic acid is also known as 4-aminobenzoic acid. 
Para aminobenzoic acid is so called since the functional group is attached to the fourth carbon in the benzene ring. 
Since this carbon is present in the para position, it is also called para aminobenzoic acid. 
Because of the benzene ring, Para aminobenzoic acid is considered an organic compound. 
The formula for Para aminobenzoic acid is H2NC6H4CO2H. 
Para aminobenzoic acid is a white solid compound. 
However, find that the commercially available Para aminobenzoic acid is grey in color. 
The organic compound is slightly soluble in water. 
Para aminobenzoic acid has carboxyl and amino groups attached to the benzene ring.

CHEMICAL SYNTHESIS of Para Aminobenzoic Acid:
In industries, Para aminobenzoic acid is prepared by two routes. 
In one of the processes, terephthalic acid is used. 
Monoamide is produced from terephthalic acid. 
Hoffman degradation of this monoamide results in the formation of Para aminobenzoic acid.
In another process, 4-nitrobenzoic acid is reduced to form Para aminobenzoic acid. 
This reaction takes place in a controlled manner. 
Para aminobenzoic acid can also be obtained from different food sources like Brewer’s yeast, liver, unfiltered beer, molasses, mushrooms, whole grains, and animal kidneys.

PRODUCTION of PARA-AMINOBENZOIC ACID:
In industry, PABA is prepared mainly by two routes:
-Reduction of 4-nitrobenzoic acid
-Hoffman degradation of the monoamide derived from terephthalic acid.
Food sources of PABA include liver, brewer's yeast (and unfiltered beer), kidney, molasses, mushrooms, and whole grains.

PHYSICAL and CHEMICAL PROPERTIES of PARA-AMINOBENZOIC ACID:
Molecular Weight: 137.14
Appearance Form: solid
Color: white, to, tan
Odor: odorless
Odor Threshold: Not applicable
pH: 3,5 at 5 g/l at 20 °C
Melting point/freezing point:
Melting point/range: 187 - 189 °C - lit.
Initial boiling point and boiling range: 200 °C at 13,33 hPa
Flash point: 171 °C - closed cup
Evaporation rate: No data available
Flammability (solid, gas): No data available
Upper/lower flammability or explosive limits: No data available
Vapor pressure: No data available
Vapor density: No data available
Density: 1,374 g/cm3 at 25 °C - lit.
Relative density: No data available
Water solubility: 4,7 g/l at 20 °C 6,11 g/l at 30 °C
Partition coefficient: n-octanol/water
log Pow: 0,83 - Bioaccumulation is not expected., (Lit.)
Autoignition temperature: No data available
Decomposition temperature: 285 °C -
Viscosity 
Viscosity, kinematic: No data available
Viscosity, dynamic: No data available
Explosive properties: No data available
Oxidizing properties: none
Dissociation constant: 4,65 at 20 °C
Solubility: Soluble in ethanol (50 mg/ml), water (4.7 g/l at 20° C), chloroform, ethyl acetate, benzene (slightly), DMSO, and methanol.
Storage: Store at room temperature
Boiling Point: 340° C
Density: 1.374 g/cm3 at 25° C
Refractive Index: n20D 1.64

FIRST AID MEASURES of PARA-AMINOBENZOIC ACID:
-Description of first-aid measures
*If inhaled:
After inhalation: 
Remove from exposure and move to fresh air immediately. 
If not breathing, give artificial respiration. 
If breathing is difficult, give oxygen. 
Get medical aid.
Fresh air.

*In case of skin contact:
In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with water/ shower.
Get medical aid. 
Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. 
Wash clothing before reuse.

*In case of eye contact:
After eye contact: rinse out with plenty of water. 
Remove contact lenses.
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. 
Get medical aid.

*If swallowed:
After swallowing: 
Make victim drink water (two glasses at most). 
Consult doctor if feeling unwell.
Never give anything by mouth to an unconscious person. 
Get medical aid. 
Do NOT induce vomiting. 
If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water.

ACCIDENTAL RELEASE MEASURES of PARA-AMINOBENZOIC ACID:
-Personal precautions, protective equipment and emergency procedures:
-Environmental precautions
Do not let product enter drains.
-Methods and materials for containment and cleaning up
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions.
Take up dry. 
Dispose of properly. 

FIREFIGHTING MEASURES of PARA-AMINOBENZOIC ACID:
-Extinguishing media:
Suitable extinguishing media:
Water Foam Carbon dioxide (CO2) Dry powder
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of PARA-AMINOBENZOIC ACID:
-Control parameters:
Ingredients with workplace control parameters:
-Exposure controls:
Personal protective equipment:
*Eye/face protection
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU). 
Safety glasses.

*Skin protection
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
Full contact
Material: Nitrile rubber
Minimum layer thickness: 0,11 mm
Break through time: 480 min
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0,11 mm
Break through time: 480 min

*Respiratory protection:
Required when dusts are generated.
Our recommendations on filtering respiratory protection are based on the following standards: DIN EN 143, DIN 14387 and other accompanying standards relating to the used respiratory protection system.
Recommended Filter type: Filter type P1
The entrepeneur has to ensure that maintenance, cleaning and testing of respiratory protective devices are carried out according to the instructions of the producer.
These measures have to be properly documented.

HANDLING and STORAGE of PARA-AMINOBENZOIC ACID:
*Storage conditions:
Tightly closed. 
Dry.
Keep container closed when not in use. 
Keep under a nitrogen blanket. 
*Storage stability:
Recommended storage temperature
2 - 8 °C.
*Handling: 
Use with adequate ventilation. 
Keep container tightly closed. 

SYNONYMS:
4-Aminobenzoic Acid
p-aminobenzoic acid
Aminobenzoic Acid
Benzoic acid, 4-amino-
Benzoic acid, p-amino-
p-Carboxyaniline
p-Carboxyphenylamine
PABA
4-Aminobenzoate
p-Aminobenzoate
Amben
anti-Chromotrichia Factor
Anticanitic vitamin
Pabacyd
Pabafilm
Pabamine
Paraminol
Paranate
4-Amino-Benzoesaeure
p-Amino-benzoesaeure
Vitamin BX
Anticanitic vitamin
1-Amino-4-carboxybenzene
Aniline-4-carboxylic acid