Limonin is a limonoid

Limonoid

Limonoids are phytochemicals, abundant in citrus fruit and other plants of the families Rutaceae and Meliaceae. Currently limonoids are under investigation for a wide variety of therapeutic effects such as antiviral or Viricide, antifungal, antibacterial, antineoplastic and antimalarial...

, and a bitter, white, crystalline substance found in citrus

Citrus

Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...

 and other plants. It is also known as limonoate D-ring-lactone and limonoic acid di-delta-lactone. Chemically, it is a member of the class of compounds known as furanolactone

Furanolactone

A furanolactone is a heterocyclic chemical compound that contains both a lactone and a furan ring structure.Examples include:* The Salvinorins, including the hallucinogenic compound salvinorin A* Columbin, a potential chemopreventive compound...

s.

Sources

Limonin is enriched in citrus fruits and is often found at higher concentrations in seeds, for example orange

Orange (fruit)

An orange—specifically, the sweet orange—is the citrus Citrus × sinensis and its fruit. It is the most commonly grown tree fruit in the world....

 and lemon

Lemon

The lemon is both a small evergreen tree native to Asia, and the tree's ellipsoidal yellow fruit. The fruit is used for culinary and non-culinary purposes throughout the world – primarily for its juice, though the pulp and rind are also used, mainly in cooking and baking...

 seeds. Limonin is also present in plants such as those of the Dictamnus

Dictamnus

Dictamnus is a genus of flowering plant in the family Rutaceae, with a single species, Dictamnus albus. It is known variously as Burning-bush, False Dittany, White Dittany, Gas-plant and Fraxinella. It is a perennial herb, native to southern Europe, north Africa and throughout...

 genus.

Presence in citrus products

Limonin and other limonoid compounds contribute to the bitter taste of some citrus food products. Researchers have proposed removal of limonoids from orange juice

Orange juice

Orange juice is a popular beverage made from oranges. It is made by extraction from the fresh fruit, by desiccation and subsequent reconstitution of dried juice, or by concentration of the juice and the subsequent addition of water to the concentrate...

 and other products (known as "debittering") through the use of polymeric films.

Bioactivity and research

Ongoing research programs are examining the effects of limonin in human diseases. Citrus seed extracts reportedly have antiviral properties, inhibiting replication of retrovirus

Retrovirus

A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA...

es like HIV

HIV

Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...

-1 and HTLV-I. Neuroprotective effects of limonin have also been described. Limonin reduces proliferation of colon cancer cells and has been tested as an anti-obesity agent

Anorectic

An anorectic or anorexic , also known as anorexigenic or appetite suppressant, is a dietary supplement and/or drug which reduces appetite, food consumption, and as a result, causes weight loss to occur.-List of anorectics:Numerous pharmaceutical compounds are marketed as appetite suppressants.The...

 in mice.

External links

• PubChem Compound Summary
• "Citrus Compound: ready to help your body!" (Agricultural Research Service, USDA)