Tabebuia avellanedae Lorentz ex Griseb. (Taheebo): In Vitro Culture and the Production of Naphthoquinones

Abstract

Bignoniaceous plants of the genus Tabebuia grow throughout southern North America to South America. Tabebuia avellanedae Lorentz and Griseb. [synonym T. heptaphylla Vellosoi Toledo, T. impetiginosa Mart. ex DC. (Standl.), and T. ipê (Mart. ex Schum.) Standl.] is native to South America from Brazil to northern Argentina (Williams 1936; Hashimoto 1962; da Silva et al. 1977). The bark of the plant has been used as a diuretic and astringent. This plant has many colloquial names: Ipê, Ipê roxo, Ipê cavatan, Ipê comum, Ipê de São Paulo, Ipeuva, Aipê, Cavatan, Guiraiba, Lapacho, Pau d’Arco Roxo, Pau d’ArcoVelmelho, Peuva, Peuva roxa, Piuva, Queraiba, or Upeuva in Brazil; Lapacho or Lapacho negro in Argentina; Lapacho in Paraguay; Tayihú in Guarani; and Taheebo in ancient Inca (Hashimoto 1962; da Silva et al. 1977; Accorsi 1988). In an ancient language of the Incas, Quechua, which is still retained by the inhabitants of the sierras, Tabebuia species are called Tahuari (Williams 1936). T. avellanedae grows well in the semitropical regions of Brazil. The erect trunk of the tree with its spreading branches reaches a height of 30–50 m. The palmate compound leaves are composed of five to seven microphylls. The leaves are opposite, sharply toothed, and long pointed. The five-lobed rosy or purple showy blossoms, similar in shape to those of the genus Catalpa, open in mid- July to September (Fig. 1). The plants bear long suspended pods containing numerous seeds in September to October. The seeds are broadly winged. The timber is valuable for general construction and cabinetwork. The recent rediscovery of Tabebuia plants as effective drugs for cancer has made T. avellanedae an important medicinal resource (Hartwell 1968; Gottlieb and Mors 1980; M.M. Rao and Kingston 1982; Accorsi 1988; Ueda and Tokuda 1990; Zani et al. 1991; Saizarbitoria et al. 1992).