''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, e.g., including only woody plants with secondary growth, only ...

in the family Quillajaceae, native to warm temperate central

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

. 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 Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

3–5 cm long; white star-shaped

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

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 re ...

s; and a dry

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

with five follicles each containing 10–20

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s. The tree has several practical and commercial uses.

Habitat

This tree occurs at elevations up to 2000 metres. The species is

drought A drought is a period of 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, ...

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 and Cerro La Campana, in which locales it is associated with the Chilean wine palm, '' Jubaea chilensis''. It is often used for

reforestation Reforestation is the practice of restoring previously existing forests and woodlands that have been destroyed or damaged. The prior forest destruction might have happened through deforestation, clearcutting or wildfires. Three important purpose ...

arid Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata ...

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s. The plant has been introduced as an ornamental in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, and has been acclimatized in

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

but is 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'.

Uses

The wood is used in cabinetry, and scents derived from the tree are used in perfumes and cosmetics. The inner bark of ''Quillaja saponaria'' can be reduced to powder and employed as a substitute for

soap Soap is a salt (chemistry), salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually u ...

, 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 glycosides. ...

saponin Saponins (Latin ''sapon'', 'soap' + ''-in'', 'one of') are bitter-tasting, usually toxic plant-derived secondary metabolites. They are organic chemicals that become foamy when agitated in water and have high molecular weight. They are present ...

, sometimes distinguished as

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

saponin. The same, or a closely similar substance, is found in soapwort ('' Saponaria officinalis''), 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 worldsarsaparilla; 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 Biennial plant, biennials, commonly called foxgloves. ''Digitalis'' is native to Europe, Western Asia, and northwestern Africa. The flowers are ...

''.

Quillaja saponaria UC Berkeley July 2019 by Amber Kerr

Uses of the saponins

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

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

people who used it as a treatment for various chest problems.Chevallier, A., ''The Encyclopedia of Medicinal Plants'', 1996 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 fluid, serous and muc ...

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 throat nasal passages. It often refers to respiratory mucus expelled by coughing, otherwise known as ...

through coughing. The bark is the source of

, the extract of which is used as a

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...

and as an ingredient in

pharmaceutical Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, 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 ...

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

s, personal care products, fire-fighting foam, and applied as an agricultural spray adjuvant. 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 increas ...

for drinks. The saponins in Quillaja Extract are also used as the active ingredient in commercial pesticides to inhibit the growth of pathogenic fungi and nematodes in ornamental plants, food crops and turfgrass. 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 * Anal ...

properties for

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

solutions.Singh, Manmohan, 2007. ''Vaccine Adjuvants and Delivery Systems'', page 193 QS21 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 sy ...

vaccine for

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 can vary but often include fever ...

uses this adjuvant, the

zoster vaccine A zoster vaccine is a vaccine that reduces the incidence of herpes zoster (shingles), a disease caused by reactivation of the varicella zoster virus, which is also responsible for chickenpox. Shingles provokes a painful rash with blisters, ...

''Shingrix'' also contains QS21 as well as the RSV vaccine ''Arexvy''.

Toxicity

First described by Edwin John Quekett, ''Q. saponaria'' wood and bark is known to contain

raphide Raphides ( ; singular ''raphide'' or ''raphis'') are needle-shaped crystals of calcium oxalate monohydrate ( prismatic monoclinic crystals) or calcium carbonate as aragonite ( dipyramidal orthorhombic crystals), found in more than 200 familie ...

s, which George Gulliver found were concentrated along the liber and mesophloeum.

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 Flora of the Chilean Matorral Flora of central Chile Trees of Chile Trees of Mediterranean climate Drought-tolerant trees Medicinal plants saponaria Saponaceous plants