Mellein is a

dihydroisocoumarin Dihydroisocoumarins are phenolic compounds related to isocoumarin. Dihydroisocoumarin glucosides A glucoside is a glycoside that is chemically derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced whe ...

, a phenolic compound produced by the mold species ''

Aspergillus ochraceus ''Aspergillus ochraceus'' is a mold species in the genus ''Aspergillus'' known to produce the toxin ochratoxin A, one of the most abundant food-contaminating mycotoxins, and citrinin. It also produces the dihydroisocoumarin mellein. It is a fil ...

''.

Derivatives

4-Hydroxymellein is also produced by ''

''. 6-Hydroxymellein, together with

S-adenosyl methionine ''S''-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur thro ...

, is a substrate of the enzyme 6-hydroxymellein O-methyltransferase to form 6-methoxymellein and S-adenosylhomocysteine in

Apiaceae 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 p ...

.6-methoxymellein biosynthesis pathway on www.biocyc.org
/ref> 6-Methoxymellein is one of the compounds responsible for bitterness in carrots.

References

Dihydroisocoumarins {{phenol-stub