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MAGNOLIACEAE
This family consists of 230 species in 12 genera found in temperate and tropical eastern Asia and America. Oil passages are present in the tissues of the plants. [Summary yet to be added] The genus comprises two species, one native to eastern North America, the other native to China. The North American species, Liriodendron tulipifera L., is planted as an ornamental and as a shade tree, reaching 60 m in height. Hybrids between the two species, which are fertile, are known as Liriodendron × chinamerica (Mabberley 2008).
The timber is known in commerce as American whitewood, Canary whitewood, or yellow poplar. Dermatitis from the wood, which was used for making pianos, was reported by Brezina in 1912 (Hausen 1973). Two patients had dermatitis of the hands and face from whitewood sawdust; in one of them, a patch test to the sawdust produced a positive reaction, negative in ten controls (Hausen 1970). Four of five individuals who were contact-sensitive to sesquiterpene lactones of Compositae species and of Frullania showed positive patch test reactions to the leaf (Mitchell 1975). The sesquiterpene lactones, liperolide and γ-liriodenolide from the leaf (Doskotch et al. 1972) and tulipinolide and costunolide from the root bark (Doskotch & El-Feraly 1969) are potentially allergenic (Mitchell and Dupuis 1971). Costunolide is probably an allergen of Saussurea (Mitchell and Epstein 1974). These findings suggest that the allergens of Liriodendron may be sesquiterpene lactones. In two cases, quinones seemed to be the allergens of the wood (Hausen, B.M. Pers. Comm. 1974). 80 species are found from the Himalayan mountains east to Japan, Borneo and Java and in eastern North America and the West Indies south to Venezuela. Magnolia kobus provides an essential oil, the principal constituents of which are citral, eugenol and cineol (Kariyone 1971). A phenolic compound, magnolol, is sometimes found as fine crystals in the bark of some Magnolia species (Kariyone 1972).
The flowers yield Oil of Champaca of perfumery (Arctander 1960) which contains esters of benzoic acid, benzaldehyde, benzyl alcohol and isoeugenol (Budavari 1996). Four of five individuals who were contact sensitive to sesquiterpene lactones of Compositae species and of Frullania showed positive patch test reactions to Oil of Champaca (Mitchell 1975). In one of five cases the leaf produced a positive patch test reaction. The root of the plant yields parthenolide (Govindachari et al. 1964). An essential oil of perfumery has been derived from the plant (Arctander 1960). The leaves were boiled to make a dye. A dyer developed contact dermatitis of the hands from this work, subsequently of the face, possibly from exposure to the vapour. A patch test produced a positive reaction negative in controls. Patch test dermatitis appeared at the sites of contact with the cut edge and pin prick holes in the leaf indicating that damage to the leaf was necessary to release the allergenic principle (Genner and Bonnevie 1938). Five individuals who were contact sensitive to sesquiterpene lactones of Compositae species and of Frullania showed positive patch test reactions to cut pieces of the leaf of Magnolia grandiflora (Mitchell 1975). The finding that damage to the plant tissues was necessary to release the allergen was confirmed. Parthenolide, a sesquiterpene lactone, has been isolated from the leaves and stems of this species (Wiedhopf et al. 1973). Parthenolide was found to produce positive patch test reactions in individuals who were contact-sensitive to various Compositae species and sesquiterpene lactones (Mitchell and Dupuis 1971). These findings suggest that such lactones may be the allergens of Magnolia.
Talapatra et al. (1973) reported the presence of parthenolide and some other sesquiterpene lactones in the bark from Michelia lanuginosa. Parthenolide has been found to produce positive patch test reactions in individuals who were contact sensitive to various Compositae species and sesquiterpene lactones (Mitchell and Dupuis 1971). These findings suggest that such lactones may be the allergens of Michelia (Mitchell 1975).
In the case of contact dermatitis described by Genner and Bonnevie (1938), a dry leaf of Magnolia hypoleuca produced a positive patch test reaction, weaker in degree than that produced by Magnolia grandiflora.
[Information available but not yet included in database]
Song et al. (1998) reported the presence of costunolide, parthenolide and other sesquiterpene lactones in the leaves of this species, with maximal levels of parthenolide occurring in July and August. Parthenolide and costunolide have been found to produce positive patch test reactions in individuals who are contact sensitive to various Compositae species and sesquiterpene lactones (Mitchell and Dupuis 1971). References
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