Tabebuia rosea

The naphthoquinones with acid hydroxyl function like lapachol are easily extracted with bases. They are also extracted in a Soxhlet apparatus with EtOH, and the resulting extract is then exhaustively extracted with AcOEt to yield a residue rich in naphthoquinones [115-116]. The naphthoquinones are mainly isolated from the wood and heartwood but there some examples of isolation from the roots [46, 48, 53, 58, 65, 66, 75, 78]. The study of commercial herbal products sold as Taheebo, Pau d Arco, Lapacho, and Ipe roxo carried out by Girard et al [117], showed important differences in the content of lapachol and other related naphthoquinones present in extracts of Tabebuia ssp Tabebuia rosea, T. cassinoides, T. impetiginosa, and T. chrisantha. Similar works using HPLC techniques have been carried out by Awang et al. [118]. 

Joshi K C, Bansal R K, Singh P 1974 Mass and NMR spectral studies of sitost-4-en-3-one from Tabebuia rosea DC. Indian J Chem 12 903-904... 

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