3-Dehydroquinic acid is the first carbocyclic intermediate of the shikimate pathway. It is created from 3-deoxyarabinoheptulosonate 7-phosphate, a 7-carbon ulonic acid, by the enzyme DHQ synthase. The mechanism of ring closure is complex, but involves an aldol condensation

Aldol condensation

An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone....

 at C-2 and C-7. It has the same structure as quinic acid

Quinic acid

Quinic acid is a cyclitol, a cyclic polyol. It is a crystalline acid obtained from cinchona bark, coffee beans, and other plant products and made synthetically by hydrolysis of chlorogenic acid. Quinic acid is also implicated in the perceived acidity of coffee...

, which is found in coffee

Coffee

Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...

, but the C-3 hydroxyl

Hydroxyl

A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...

 is oxidized to a ketone

Ketone

In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...

 group. 3-Dehydroquinic acid undergoes five further enzymatic steps in the remainder of the shikimate pathway to chorismic acid, a precursor to tyrosine

Tyrosine

Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...

, 3-phenylalanine

Phenylalanine

Phenylalanine is an α-amino acid with the formula C6H5CH2CHCOOH. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain. L-Phenylalanine is an electrically neutral amino acid, one of the twenty common amino acids used to biochemically form...

, 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...

, and some vitamins, including:

• Vitamin K
  Vitamin K
  Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
  
  
• Pteroylmonoglutamic acid, called folate.

3-Dehydroquinate can also be a precursor to pyrroloquinoline quinone

Pyrroloquinoline quinone

Pyrroloquinoline quinone was discovered by J.G. Hauge as the third redox cofactor after nicotinamide and flavin in bacteria . Anthony and Zatman also found the unknown redox cofactor in alcohol dehydrogenase and named it methoxatin...

(PQQ), an alternate redox

Redox

Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....

 coenzyme involved in oxidative phosphorylation

Oxidative phosphorylation

Oxidative phosphorylation is a metabolic pathway that uses energy released by the oxidation of nutrients to produce adenosine triphosphate . Although the many forms of life on earth use a range of different nutrients, almost all aerobic organisms carry out oxidative phosphorylation to produce ATP,...

.

Biosynthesis

3-Dehydroquinate goes through beta oxidation

Beta oxidation

Beta oxidation is the process by which fatty acids, in the form of Acyl-CoA molecules, are broken down in mitochondria and/or in peroxisomes to generate Acetyl-CoA, the entry molecule for the Citric Acid cycle....

, similar to fatty acid

Fatty acid

In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

s. Then, this compound (6-oxo-3-dehydro-quinate) is transaminated

Transamination

There are two chemical reactions known as transamination . The first is the reaction between an amino acid and an alpha-keto acid...

 to 6-amino-3-dehydroquinate. Then 6-amino-3-dehydro-quinate is dehydrated

Dehydration reaction

In chemistry and the biological sciences, a dehydration reaction is usually defined as a chemical reaction that involves the loss of water from the reacting molecule. Dehydration reactions are a subset of elimination reactions...

 and reduced

Redox

Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....

 to 6-amino-4-desoxy-3-keto-quinate, which reacts with dehydroalanine

Dehydroalanine

Dehydroalanine is an uncommon amino acid found in peptides of microbial origin ....

 and alpha-ketoglutarate, to form hexahydro-pyrroloquinoline quinone. This compound is oxidized by FAD

FAD

In biochemistry, flavin adenine dinucleotide is a redox cofactor involved in several important reactions in metabolism. FAD can exist in two different redox states, which it converts between by accepting or donating electrons. The molecule consists of a riboflavin moiety bound to the phosphate...

to PQQ.