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CAPPARACEAE(Caper family)
Previously known as the Capparidaceae, the caper family is related to the Cleomaceae and to the Cruciferae. It comprises some 650 species of small trees and shrubs in 30 genera which are found principally in tropical and warm temperate regions. A few species may be encountered in cultivation, but only rarely. Capers, the flower buds of Capparis spinosa L., are pickled and used as a condiment. The flower buds of Capparis corymbifera E.Mey., C. decidua Edgew. (syn. C. aphylla Roth) and Boscia albitrunca Gilg & Benedict have also been used. In addition, the fruits of C. decidua Edgew. and C. mitchellii Lindl. are known to be edible (Hutchinson 1967). Members of this family contain thioglucosides (known as glucosinolates) which release isothiocyanates ("mustard oils") when the plants are damaged. Typically, the plants yield methyl isothiocyanate from methyl glucosinolate, otherwise known as glucocapparin. These mustard oils have skin irritant activity and may also have contact allergenic activity (Mitchell 1974, Mitchell & Jordan 1974, Richter 1980). A number of species are spiny.
These species yield a pungent principle similar to that of Capparis L. species (Watt & Breyer-Brandwijk 1962). The plant contains glucocapparin from which the mustard oil methyl isothiocyanate is released when the plant material is crushed (Ahmed et al. 1972). The wood from this species can cause dermatitis (Koelsch 1959). The seeds of this species have been found to contain glucocapparin from which methyl isothiocyanate is released when the plant material is crushed (Ahmed et al. 1972). Methyl isothiocyanate is a known irritant and sensitiser. About 250 species are to be found in warm climates; some may be cultivated in temperate regions. The following species have been reported to contain glucocapparin and/or other glucosinolates from which methyl isothiocyanate and/or other mustard oils are released when the plant material is crushed (Ahmed et al. 1972):
The flower buds, "pasi", of this spiny tree are cooked as a potherb, and also pickled (Jacobs 1965). The shoots and young leaves contain a rubefacient and vesicant principle (Chopra & Badhwar 1940, Behl et al. 1966). The seeds contain glucocapparin (Juneja et al. 1971) from which the mustard oil methyl isothiocyanate is released when the plant material is crushed. The West African colloquial name is probably generally used for prickly climbing plants (Dalziel 1937). Jacobs (1965) believes this species to be closely related to Capparis baducca Rheede. Verdcourt & Trump (1969) note that this species forms a very thorny scrambling shrub. The roots are very pungent, like horseradish, and may blister the skin (Morton 1981). Ahmed et al. (1972) reported the presence of glucocapparin in this species, from which methyl isothiocyanate is released when the plant material is crushed. The Malay word melada refers to the fact that the seeds are spicy and peppery. The same sharp cress- or mustard-like taste occurs also in many other Capparis species (Corner 1952).
The leaves and seeds of these spiny shrubs have been found to contain glucocapparin from which the mustard oil methyl isothiocyanate is formed when the plant material is crushed (Kjær 1960, Ahmed et al. 1972). Khakberdyev et al. (1968) described experiments involving the oral administration of a preparation of the root of C. spinosa to guinea pigs prior to challenge with a subcutaneous injection of various animal and vegetable allergens to which the animals had been sensitised. In all cases, animals treated with the C. spinosa preparation suffered no ill effects whilst those untreated died of anaphylactic shock.
The root is used as a counter-irritant in southern Africa (Watt & Breyer-Brandwijk 1962). [Further information available but not yet included in database] The leaves are considered to be powerfully rubefacient (Lewis & Elvin-Lewis 1977) and counter-irritant (Nadkarni 1976). Nine species are found in tropical regions excluding Australia and New Caledonia. Much of the literature refers to Crataeva rather than Crateva species. However, the latter is considered to be the correct form since the genus was named after the Greek herbalist Kratevas (132–63 B.C.) who was renowned for his skill in poisoning.
The fresh leaves are rubefacient and counter irritant (Nadkarni 1976). The presence of glucocapparin in the bark and leaves of Crateva roxburghii R.Br. has been reported (Ahmed et al. 1972). Methyl isothiocyanate, a mustard oil, is released from glucocapparin when the plant material is crushed. Corner (1952) records that the shoots and flowers of this species and also C. lophosperma Kurz (see C. nurvala Buch.-Ham.) are eaten in curries.
Burkill (1935) notes that the bark is biting and bitter in taste and that the leaves have rubefacient and vesicant properties. Behl et al. (1966) and Nadkarni (1976) also ascribe rubefacient properties to the fresh leaves, root bark, and young shoots of this species. The fruit, during the drying process, breaks open irregularly producing an unbearable stench of cadavers. It seems not unlikely that there is a connection between this property and the habit of planting cratevas on graveyards and near temples (Jacobs 1964). The Yorubas and people of the Congo apply the leaf of this spineless tree for counter irritant purposes (Irvine 1961). The fresh leaves have rubefacient and vesicant properties (Quisumbing 1951, Nadkarni 1976). The presence of glucocapparin in the fruit of this species has been reported (Sethi et al. 1978). The mustard oil methyl isothiocyanate is released from glucocapparin when the plant material is crushed. The whole plant, when first cut, has an odour of garlic (Allium sativum L., fam. Alliaceae). The sap is acrid and caustic and can produce dermatitis (Allen 1943, Blohm 1962). The roots are used to blister the skin (Usher 1974). The seeds of this species contain glucocapparin from which the mustard oil methyl isothiocyanate is released when the seed is crushed (Ahmed et al. 1972). Hedge et al. (1980) found this species to contain glucocapparin, providing chemical evidence for the placement of this taxon in the family Capparaceae rather than in the Cruciferae. When crushed, glucocapparin-containing plant material releases methyl isothiocyanate. The seeds have a peppery taste and the flowers a peculiar pungent odour (Dalziel 1937). This plant is found growing naturally in the deserts of south-western North America. It is a spiny, usually leafless much-branched shrub, which is capable of puncturing or tearing the skin. The genus is monotypic, but two varieties are recognised, namely Koeberlinia spinosa var. spinosa and Koeberlinia spinosa var. tenuispina Kearney & Peebles. Some authorities classify these plants in their own family, namely the Koeberliniaceae.
These species contain glucocapparin from which the mustard oil methyl isothiocyanate is released when the plant material is crushed (Ahmed et al. 1972). This species has rubefacient properties (Verdcourt & Trump 1969). The bark and roots contain glucocapparin from which the mustard oil methyl isothiocyanate is released when the plant material is crushed (Ahmed et al. 1972).
These species contain glucocapparin from which the mustard oil methyl isothiocyanate is released when the plant material is crushed (Ahmed et al. 1972). References
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