Quassia amara

Quassia amara
Quassia amara from Koehler's Medicinal-Plants (1887)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Sapindales
Family:	Simaroubaceae
Genus:	Quassia
Species:	Q. amara
Binomial name
Quassia amara L.

Flower

Quassia amara (Amargo, Bitter-ash, Bitter-wood) is a species in the genus Quassia, with some botanists treating it as the sole species in the genus. The genus was named by Carolus Linnaeus who named it after the first botanist to describe it: the Surinamese freedman Graman Quassi. Q. amara is used as insecticide, in traditional medicine and as additive in the food industry.

Leaf

Morphology and Origin

It is a shrub or rarely a small tree, growing to 3 m tall (rarely 8 m). The leaves are compound and alternate, 15–25 cm long, and pinnate with 3-5 leaflets, the leaf rachis being winged. The flowers are produced in a panicle 15–25 cm long, each flower 2.5-3.5 cm long, bright red on the outside, and white inside. The fruit is a small drupe 1-1.5 cm long.
Q. amara is native to Costa Rica, Nicaragua, Panama, Brasil, Peru, Venezuela, Suriname, Colombia, Argentina, French Guiana and Guyana. Q. amara is widely planted outside its native range.

Chemical composition

In the wood a share of 0.09 to 0.17% of quassin and 0.05 to 0.11% of neoquassin was detected in Costa Rician plants.^[1] Quassin is one of the most bitter substances found in nature.

Other identified components of bitterwood are: beta-carbolines, beta-sitostenone, beta-sitosterol, dehydroquassins, gallic acid, gentisic acid, hydroxyquassins, isoparain, isoparaines, isoquassins, malic acid, methylcanthins, methoxycanthins, methoxycantins, nigakilactone A, nor-neoquassin, parain, paraines, quassialactol, quassimarin, quassinol, quassol and simalikalactone D.^[2]

Structure of quassin

Uses

Insecticide

Extracts of Quassia wood or bark act as a natural insecticide. For organic farming this is of particular interest. A good protection was shown against different insect pests (e.g. aphids, Colorado potato beetle, Anthonomus pomorum, Rhagoletis cerasi, Caterpillars of Tortricidae).^[3] Quassin extract works as a contact insecticide. Adverse effects on beneficial organisms were not found.^[4]

For Switzerland, a licensed formulation is available for organic farming.

Potential Effects on Human Health

Like any poorly studied alternative chemical applied to food crops, Quassia extract may have unknown health consequences. A study on rats in 1997 found that Quassia extract significantly reduced their fertility, reducing testes size, sperm quality and serum testosterone.^[5]

Formulation

Around 200 grams of Quassia wood chips are put together with 2 liters of water. It is allowed to stand for 24 hours and then it is cooked for 30 min. It is then diluted with 10 to 20 liters of water and used as a spray^[3] The use of approximately 3-4.5 kg wood extract per hectare seems to be optimal to minimize the damage of Hoplocampa testudinea on apple trees.^[6]

Medicine

Traditionally, Q. amara is used as a digestive, to treat fever, and against hair parasites (lice, fleas) and Mosquito larvae in ponds (and do not harm the fishes).^[2]

The component Simalikalactone D was identified as an antimalarial. The preparation of a tea out of young leaves is used traditionally in French Guyana. Experiments showed a high inhibition of Plasmodium yoelii yoelii and Plasmodium falciparum.^[7]

Other uses

Extracts of Q. amara wood or bark are also used to flavor soft drinks, aperitifs and bitters which can be added to cocktails or to baked goods.^[1][2]

Cultivation

Seeds and cuttings can be used for propagation of Q. amara. Frost is not tolerated, but the plant is partially drought tolerant.^[8] A large amount of indirect light is recommended.^[9]

References