''Quillaja saponaria'', the soap bark tree or soapbark, is an evergreen

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

in the family Quillajaceae, native to warm temperate central

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

. In Chile it occurs from 32 to 40° South Latitude approximately and at up to 2000 m (6500 ft) above sea level. It can grow to 15–20 m (50–65 ft) in height. The tree has thick, dark bark; smooth, leathery, shiny, oval

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

leaves 3–5 cm long; white star-shaped

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s 15 mm diameter borne in dense

corymb Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficial ...

s; and a dry

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

with five follicles each containing 10–20

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

Characteristics

The inner bark of ''Quillaja saponaria'' can be reduced to powder and employed as a substitute for

soap Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are use ...

, since it forms a lather with water, owing to the presence of a

glycoside In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycoside ...

saponin, sometimes distinguished as

quillaia Quillaia is the milled inner bark or small stems and branches of the soapbark ( ''Quillaja saponaria'', Molina). Other names include ''Murillo bark extract'', ''Panama bark extract'', ''Quillaia extract'', ''Quillay bark extract'', and ''Soapbark ex ...

saponin. It's also applied as an agricultural spray adjuvant. The same, or a closely similar substance, is found in soapwort (''

Saponaria officinalis ''Saponaria officinalis'' is a common perennial plant from the family Caryophyllaceae. This plant has many common names, including common soapwort, bouncing-bet, crow soap, wild sweet William, and soapweed. There are about 20 species of soapwo ...

''), in senega root (''

Polygala ''Polygala'' is a large genus of flowering plants belonging to the family Polygalaceae. They are commonly known as milkworts or snakeroots. The genus is distributed widely throughout much of the world sarsaparilla Sarsaparilla often refers to the sarsaparilla soft drink, made from Smilax plants. Sarsaparilla may also refer to: Biology *Several species of plants, of the genus ''Smilax'', including: **''Smilax ornata'', also known as Honduran or Jamaican sar ...

; it appears to be chemically related to

digitonin Digitonin is a steroidal saponin (saraponin) obtained from the foxglove plant ''Digitalis purpurea''. Its aglycone is digitogenin, a spirostan steroid. It has been investigated as a detergent, as it effectively water-solubilizes lipids. As such, ...

, which occurs in ''

digitalis ''Digitalis'' ( or ) is a genus of about 20 species of herbaceous perennial plants, shrubs, and biennials, commonly called foxgloves. ''Digitalis'' is native to Europe, western Asia, and northwestern Africa. The flowers are tubular in shap ...

''. The wood is used in cabinetry, and scents derived from the tree are used in perfumes and cosmetics. Quillaja saponaria UC Berkeley July 2019 by Amber Kerr

Quillaja saponaria UC Berkeley July 2019 by Amber Kerr

Uses

Soap bark tree has a long history of medicinal use with the

Andean The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S l ...

people who used it as a treatment for various chest problems. It is the source of

, the extract of which is used as a food additive and as an ingredient in

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field an ...

s, personal care products, and fire-fighting foam. It is used as an additive in photographic films and as a

foaming agent A foaming agent is a material such as a surfactant or a blowing agent that facilitates the formation of foam. A surfactant, when present in small amounts, reduces surface tension of a liquid (reduces the work needed to create the foam) or increase ...

for drinks. The saponin content of the bark helps to stimulate the production of a more watery

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...

in the airways, thus facilitating the removal of

phlegm Phlegm (; , ''phlégma'', "inflammation", "humour caused by heat") is mucus produced by the respiratory system, excluding that produced by the nasal passages. It often refers to respiratory mucus expelled by coughing, otherwise known as sputum ...

through coughing. The saponins of this tree are also considered to have

adjuvant In pharmacology, an adjuvant is a drug or other substance, or a combination of substances, that is used to increase the efficacy or potency of certain drugs. Specifically, the term can refer to: * Adjuvant therapy in cancer management * Analgesi ...

properties for

vaccine A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.

solutions.

QS21 QS-21 is a purified plant extract used as a vaccine adjuvant. It is derived from the soap bark tree (''Quillaja saponaria''), which is native to the countries of Chile, Peru, and Bolivia. The crude drug (''Quillajae cortex'') is imported from ...

adjuvant is a saponin obtainable from ''Quillaja saponaria'' extract. The

Novavax Novavax, Inc. is an American biotechnology company based in Gaithersburg, Maryland that develops vaccines to counter serious infectious diseases. Prior to 2020, company scientists developed experimental vaccines for influenza and respiratory s ...

vaccine for

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickly ...

uses this adjuvant, the zoster vaccine ''Shingrix'' also contains QS21.

Habitat

Bosque esclerófilo, Chile 001 — Inao Vásquez

This tree occurs at altitudes to 2000 metres. The species is

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

resistant, and tolerates about −12 °C (10 °F) in its natural habitat. Examples of specific occurrences are in central

in the forests of

La Campana National Park La Campana National Park is located in the Cordillera de la Costa, Quillota Province, in the Valparaíso Region of Chile. La Campana National Park and the Vizcachas Mountains lie northwest of Santiago. This national park covers approximately a ...

and Cerro La Campana, in which locales it is associated with the

Chilean Wine Palm ''Jubaea'' is a genus of palms with one species, ''Jubaea chilensis'' or ''Jubaea spectabilis'', commonly known in English as the Chilean wine palm or Chile cocopalm, and palma chilena in Spanish. It is native to southwestern South America and i ...

, ''

Jubaea chilensis ''Jubaea'' is a genus of palms with one species, ''Jubaea chilensis'' or ''Jubaea spectabilis'', commonly known in English as the Chilean wine palm or Chile cocopalm, and palma chilena in Spanish. It is native to southwestern South America and i ...

''.C. Michael Hogan. 2008 It is often used for

reforestation Reforestation (occasionally, reafforestation) is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation, but also after clearcutting. Management A debat ...

arid A region is arid when it severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic. Most ...

soil Soil, also commonly referred to as earth or dirt Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debri ...

s. It has been introduced as an ornamental in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. Trees have been acclimatized in

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

but are rarely cultivated there.

Etymology

''Quillaja'' is derived from the Chilean vernacular name for this species, ''culay''.Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 324, 340 ''Saponaria'' means 'soap-like'.

References

Sources

*C. Donoso. 2005. ''Árboles nativos de Chile. Guía de reconocimiento''. Edición 4. Marisa Cuneo Ediciones, Valdivia, Chile. 136p. *Encyclopedia of the Chilean Flora. 2009
''Quillaja saponaria''
* Adriana Hoffmann. 1998. ''Flora Silvestre de Chile, Zona Central''. Edición 4. Fundación Claudio Gay, Santiago. 254p. *C. Michael Hogan. 2008
''Chilean Wine Palm: Jubaea chilensis'', GlobalTwitcher.com, ed. Nicklas Stromberg
*J. Taylor. 1990. ''The Milder Garden''. Dent *Chevallier, Andrew, 1996. ''The Encyclopedia of Medicinal Plants'', Dorling Kindersley, 336p. *Singh, Manmohan, 2007. ''Vaccine Adjuvants and Delivery Systems'', John Wiley & Sons, Hoboken, New Jersey, 457 pp.

External links

* * * * * {{Taxonbar, from=Q2382775 Chilean Matorral Flora of central Chile Trees of Chile Trees of Mediterranean climate Drought-tolerant trees Medicinal plants

saponaria ''Saponaria'' is a genus of flowering plants in the family Caryophyllaceae, native to Asia and Europe, and are commonly known as soapworts. They are herbaceous perennials and annuals, some with woody bases. The flowers are abundant, five-petalled ...

Saponaceous plants