Prota 11(1): Medicinal plants/Plantes mιdicinales 1
Bull. Mens. Soc. Linn. Paris 1: 752 (1888).
2n = 22
Mpelepele, mwango, mtonga mwitu (Sw).
Origin and geographic distribution
Schizozygia coffaeoides occurs from DR Congo east to Somalia, Kenya and Tanzania, and south to Malawi, Angola and Mozambique and also in Comoros.
In Kenya the pounded or grated root of Schizozygia coffaeoides mixed with coconut oil is applied to sores. A root infusion is taken against dizziness. Inflamed eyes are treated by exposing them to steam from boiled leaves, while ringworm-infected skin is washed with an aqueous leaf extract.
Five schizozyganes have been isolated from the root bark and leaves of Schizozygia coffaeoides; these are hexacyclic N-acyl indole alkaloids, with schizozygine and isoschizogaline as main compounds. Schizozyganes have so far not been found elsewhere in the Apocynaceae, but they are related to certain alkaloids which occur in Hunteria and Aspidosperma. Leaf extracts show significant fungistatic activity against the dermatophytic fungi Trichophyton mentagrophytes and Microsporum gypseum, and also against Candida albicans and a phytopathogenic fungus, Cladosporium cucumerinum, indicating a broad spectrum of antifungal activity. In further tests with fungi and bacteria, it was shown that 7,8-dehydro-19β -hydroxyschizozygine was the most active antifungal compound, and isoschizogaline the only active antibacterial compound.
The fruits of Schizozygia coffaeoides are reported to be poisonous.
Shrub or small tree up to 4(8) m tall, with white latex, repeatedly dichotomously branched; bark rough, brown, lenticels pale. Leaves opposite, simple and entire; stipules absent; petiole 0.510 mm long; blade obovate, up to 25 cm Χ 11 cm, base cuneate, apex acuminate, glabrous, pinnately veined with lateral veins conspicuous. Inflorescence a congested cyme, 2 together in forks of branches, 715 mm long; peduncle up to 3 mm long; bracts narrowly oblong, 35 mm long. Flowers bisexual, 5-merous, regular, fragrant; pedicel 23 mm long; sepals free, elliptical, imbricate, 36 mm long, apex acute or acuminate; corolla creamy-yellow, tube cylindrical or urn-shaped, 45 mm long, shortly hairy around the stamens, lobes obliquely obovate to nearly hook-shaped, curved to the right, 24 mm long, in bud overlapping to right; stamens inserted in the upper part of the corolla tube, anthers sessile, triangular, introrse; ovary superior, composed of 2 free rounded carpels, style slender, pistil head with basal cylindrical part and a 2-lobed stigma. Fruit composed of 2 ellipsoid almost free follicles, 715 mm Χ 35 mm, laterally compressed, irregularly striate, glabrous, yellow to orange, dehiscent, each follicle 1-seeded. Seeds obliquely ellipsoid, 56 mm long, with a deep groove in the middle and shallowly grooved at the other side, with minute warts, surrounded by a thin pulpy red to orange aril. Seedling with epigeal germination; cotyledons ovate, rounded at base and apex.
Schizozygia comprises a single species and belongs to the tribe Tabernaemontanae. Schizozygia coffaeoides can be found flowering and fruiting throughout the year.
Schizozygia coffaeoides occurs in moist forest and riverine forest. It grows on sandy or loamy soils, up to 1500 m altitude.
Genetic resources and breeding
Schizozygia coffaeoides is fairly widespread and it does not appear to be threatened.
Work is progressing on the purification of active antifungal and antibacterial compounds in Schizozygia coffaeoides.
Barink, M.M., 1983. A revision of Pleioceras Baill., Stephanostema K. Schum. and Schizozygia Baill. (Apocynaceae). In: Leeuwenberg, A.J.M. (Editor). Series of revisions of Apocynaceae 1113. Mededelingen Landbouwhogeschool Wageningen 837. Wageningen, Netherlands. pp. 2155.
Kariba, R.M., Houghton, P.J. & Yenesew, A., 2002. Antimicrobial activities of a new schizozygane indoline alkaloid from Schizozygia coffaeoides and the revised structure of isoschizogaline. Journal of Natural Products 65(4): 566569.
Kariba, R.M., Siboe, G.M. & Dossaji, S.F., 2001. In vitro antifungal activity of Schizozygia coffaeoides Baill. (Apocynaceae) extracts. Journal of Ethnopharmacology 74: 4144.
Omino, E.A., 2002. Apocynaceae (part 1). In: Beentje, H.J. & Ghazanfar, S.A. (Editors). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 116 pp.
Omino, E.A. & Kokwaro, J.O., 1993. Ethnobotany of Apocynaceae species in Kenya. Journal of Ethnopharmacology 40: 167180.
Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.
Hajicek, J., Taimr, J. & Budesinsky, M., 1998. Revised structure of isoschizogamine. Tetrahedron Letters 39: 505508.
Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.
Timberlake, J., Golding, J. & Clarke, P., 2004. Niassa botanical expedition June 2003. Occasional Publications in Biodiversity No 12. Biodiversity Foundation for Africa, Famona, Bulawayo, Zimbabwe. 43 pp.
Correct citation of this article:
Boone, M.J., 2006. Schizozygia coffaeoides Baill. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes mιdicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.