Azobé

''Lophira alata'', commonly known as azobé, ekki or the red ironwood tree, is a species of plant in the family Ochnaceae. It is found in Cameroon, the Republic of the Congo, the Democratic Republic of the Congo, Ivory Coast, Equatorial Guinea, Gabon, Ghana, Liberia, Nigeria, Sierra Leone, Sudan, and Uganda. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss.

The timber is extremely hard and used for railroad ties, groynes and bridge planking.

Description

The trunk of ''Lophira alata'' is usually straight, without buttress roots, but sometimes with a swollen base, and is usually clear of branches up to about . The bark is typically red-brown in colour, up to two centimetres thick, and has a bright yellow layer underneath. Young trees under four metres in height have greenish-grey bark, which becomes pink or light brown as the tree matures. Inside, the living sapwood is pale pink or whitish in colour, while the inner heartwood is dark red-brown to chocolate brown, with conspicuous white deposits of silica. The leaves of ''L. alata'' are up to long and are tough, fairly narrow and elongated, with a rounded or slightly indented tip, and tend to occur in clusters at the ends of the twigs.Azobé
Retrieved 2011-08-24

Biology

''Lophira alata'' sheds all its leaves during a short period of one to two weeks, usually in December, and the re-growth of bright red young leaves, often simultaneously on all ''L. alata'' trees in an area, can set the canopy ablaze with colour. The flowers of ''L. alata'' are white, fairly large, strong-smelling, and grouped in loose, branched, terminal inflorescences. Flowering occurs in adult trees with trunks over 50 centimetres in diameter, and takes place from the time the new leaves appear. ''L. alata'' is monoecious, meaning that male and female flowers are found on the same tree, and the flowers are insect- pollinated. Fruiting takes place between January and March, the fruits becoming mature around March to April, although fruits do not always appear every year. The fruits, which are wind-dispersed, contain a single, oil-rich seed in a conical capsule, which is brown when mature and is surrounded by two unequally-sized membranous ‘wings’, one up to six centimetres long and the other twice that size. Although ''L. alata'' needs full sunlight to grow, seedlings can persist for some time in the shady undergrowth and resume growth if breaks in the canopy occur.

Uses

The timber, known as azobe, is strong and resistant making it useful for demanding constructions outdoors. The timber also has better electrical properties than other wood making it possible to use it in poles for electric fences without separate isolators. The colour is reddish brown and the wood is abrasive, dulling tools rapidly.

Sniffing the bark is used as a traditional treatment for headache. The leaves of ''Lophira alata'' afforded two new biflavonoids, lophirone L (1) and lophirone M (2), and the known luteolin and lithospermoside. Both biflavonoids were obtained in small quantities, and their structures show some new and unusual biflavonoid diversity. Likewise, two chalcone tetramers were isolated as inhibitors of Epstein–Barr virus (EBV)-activation induced by a tumor promoter, teleocidin B-4, from ''Lophira alata''. One of them was identified as lophirachalcone. The other, named alatachalcone, was new, and the structure was determined by spectral properties. Both compounds also showed potent inhibitory activities against teleocidin B-4-induced inflammation on mouse ear. In an initiation-promotion experiment on mouse skin, alatachalcone (16 nmol) significantly inhibited tumor promotion caused by 12-O-tetradecanoylphorbol-13-acetate (TPA, 1.6 nmol).Biosci Biotechnol Biochem. 1992 May;56(5):769-72. Chalcone tetramers, lophirachalcone and alatachalcone, from ''Lophira alata'' as possible anti-tumor promoters. Murakami A, Tanaka S, Ohigashi H, Hirota M, Irie R, Takeda N, Tatematsu A, Koshimizu K. Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan.

References

External links

*

{{Taxonbar, from=Q135192

Ochnaceae
Vulnerable plants
Flora of Cameroon
Flora of the Republic of the Congo
Trees of the Democratic Republic of the Congo
Flora of Ivory Coast
Flora of Equatorial Guinea
Flora of Gabon
Flora of Ghana
Flora of Liberia
Flora of Nigeria
Flora of Sierra Leone
Flora of Sudan
Flora of Uganda
Taxonomy articles created by Polbot