Indican is a colourless organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

, soluble in water, naturally occurring in Indigofera

Indigofera

Indigofera is a large genus of about 700 species of flowering plants belonging to the family Fabaceae.The species are mostly shrubs, though some are herbaceous, and a few can become small trees up to tall. Most are dry-season or winter deciduous. The leaves are pinnate with 5–31 leaflets and the...

plants. It is a precursor of indigo dye

Indigo dye

Indigo dye is an organic compound with a distinctive blue color . Historically, indigo was a natural dye extracted from plants, and this process was important economically because blue dyes were once rare. Nearly all indigo dye produced today — several thousand tons each year — is synthetic...

.

Chemical reactions

Common and significant reactions involving indican are as follows:

• Indican is a glycoside
  Glycoside
  In chemistry, a glycoside is a molecule in which a sugar is bound to a non-carbohydrate moiety, usually a small organic molecule. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme...
  
  . Its hydrolysis
  Hydrolysis
  Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
  
   yields β-D-glucose
  Glucose
  Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
  
   and indoxyl
  Indoxyl
  In chemistry, indoxyl is a nitrogenous substance with the chemical formula: C8H7NO. Indoxyl is isomeric with oxindol and is obtained as an oily liquid....
  
  .
• Reaction of indoxyl (indican) by a mild oxidizing agent
  Oxidizing agent
  An oxidizing agent can be defined as a substance that removes electrons from another reactant in a redox chemical reaction...
  
  , e.g. atmospheric oxygen, yields indigo dye
  Indigo dye
  Indigo dye is an organic compound with a distinctive blue color . Historically, indigo was a natural dye extracted from plants, and this process was important economically because blue dyes were once rare. Nearly all indigo dye produced today — several thousand tons each year — is synthetic...
  
   which is blue in colour.

Biosynthesis

A reaction, similar to the above mentioned is seen in the normal population, who excrete small amounts of the chemical in their urine. Normal urine reacting to hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...

 does at times produce a bluish tinge.
Tryptophan is first converted to indole

Indole

Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is a popular component of fragrances and the precursor to many pharmaceuticals. Compounds that contain an...

 (excreted in faeces), then to indican by bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 in the gut. Indican, being water soluble, is then excreted through the urine

Urine

Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...

. Following absorption from the gut, indole

Indole

Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is a popular component of fragrances and the precursor to many pharmaceuticals. Compounds that contain an...

 is converted to 3-hydroxy indole (indoxyl

Indoxyl

In chemistry, indoxyl is a nitrogenous substance with the chemical formula: C8H7NO. Indoxyl is isomeric with oxindol and is obtained as an oily liquid....

 or indican) in the liver, where it is again then conjugated with sulfuric acid

Sulfuric acid

Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

 or glucoronic acid through normal xenobiotic metabolism

Xenobiotic metabolism

Xenobiotic metabolism is the set of metabolic pathways that modify the chemical structure of xenobiotics, which are compounds foreign to an organism's normal biochemistry, such as drugs and poisons...

 pathways. It is then transported to the kidneys for excretion.

The enzyme "indoxyl esterase" has been found in humans and is involved in another pathway of chemical reactions involving indoxyl.

Pathology

In individuals affected by the blue diaper syndrome

Blue diaper syndrome

Blue diaper syndrome is a rare, autosomal recessive metabolic disorder characterized in infants by bluish urine-stained diapers.It is caused by a defect in tryptophan absorption. Bacterial degradation of tryptophan in the intestine leads to excessive indole production and thus to indicanuria which,...

, the patients exhibit a defect in tryptophan

Tryptophan

Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...

 metabolism. and from there into the diaper

Diaper

A nappy or a diaper is a kind of pant that allows one to defecate or urinate on oneself discreetly. When diapers become soiled, they require changing; this process is often performed by a second person such as a parent or caregiver...

 where, upon exposure to air, it is converted to indigo dye due to oxidation by atmospheric oxygen.

Indican interferes with many commercial procedures for measuring total bilirubin which can be a problem for renal failure patients where blood indican levels are raised. It can cause gastrointestinal symptoms in patients where protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 absorption is reduced - like Hartnup's disease, allowing for greater bacterial decomposition of the Tryptophan

Tryptophan

Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...

 to indole

Indole

Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is a popular component of fragrances and the precursor to many pharmaceuticals. Compounds that contain an...

and its conversion to indican.